New User Special Price Expires in

Let's log you in.

Sign in with Facebook


Don't have a StudySoup account? Create one here!


Create a StudySoup account

Be part of our community, it's free to join!

Sign up with Facebook


Create your account
By creating an account you agree to StudySoup's terms and conditions and privacy policy

Already have a StudySoup account? Login here

AP Biology

by: Vicki Chow

AP Biology LING 100

Marketplace > Biology > LING 100 > AP Biology
Vicki Chow
Introduction to Languages and Linguistics

Almost Ready


These notes were just uploaded, and will be ready to view shortly.

Purchase these notes here, or revisit this page.

Either way, we'll remind you when they're ready :)

Preview These Notes for FREE

Get a free preview of these Notes, just enter your email below.

Unlock Preview
Unlock Preview

Preview these materials now for free

Why put in your email? Get access to more of this material and other relevant free materials for your school

View Preview

About this Document

Complete AP Biology study guide based on 2012-2013 course material.
Introduction to Languages and Linguistics
Biology, Science, AP, Advanced Placement, Study Guide
75 ?




Popular in Introduction to Languages and Linguistics

Popular in Biology

This 69 page Bundle was uploaded by Vicki Chow on Wednesday September 10, 2014. The Bundle belongs to LING 100 at a university taught by a professor in Winter. Since its upload, it has received 361 views.

Similar to LING 100 at University


Reviews for AP Biology


Report this Material


What is Karma?


Karma is the currency of StudySoup.

You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!

Date Created: 09/10/14
Term 1 Evolution EVOLUTION ORGANISMIC EVOLUTION changes in populations species or groups species both a pattern amp a process occurs because populations vary by the frequency of heritable traits represented by alleles for genes that modify morphology form or structure physiology or behaviour changes in allele frequencies in populations over time Microevolution A describes details of how populations of organisms change from generation to generation amp how new species originate change in allele frequencies in a population over generation Macroevolution A describes patterns of changes in groups of related species over broad periods of geologic time Qgt patterns determine phylogeny A evolutionary relationships between species amp groups of species systematics A classification of organism amp determination of evolutionary relationships abundant evidence A some species change over time other species diverge into one or more new species others become extinct 4gt MENDEL proposed a model for pattern of inheritance parents passed on discrete units genes to offspring Discrete characters A eitheror basis eg widow39s peak Quantitative characters A vary along a continuum eg hair colour LAMARCK one of the earliest advocates for the idea of evolution Three ideas Qgt Use amp disuse A body parts of an organism will develop or weaken with usage Qgt Inheritance of acquired traits A body features acquired during the lifetime of an organism can be passed on to offspring A only change in genetic material can be passed on Qgt Natural transformation of species A each subsequent generation is slightly different A towards some ultimate higher order of complexity incorrect PALEONTOLOGY provides fossils that reveal prehistoric existence of extinct species A changes in species amp formation of new species can be studied Stlta A sedimentary rock which appears in layers deeper amp older A more dissimilar to current life gt Qgt new species appeared amp disappeared Qgt Catastrophism A each boundary between strata represents a catastrophe extinctions were common BIOG EOGRAPHY unrelated species in different regions of the world when found in similar environments A natural selection in evolution PHYLOGENETIC SPECIES CONCEPT shared common ancestor amp different from others with a separate common ancestor CLADOGENESIS separate species formed from branching off a common ancestor ANAGENESIS one species evolving from a common ancestor without any other species being formed in the process PAEDOMORPHIC keeping a trait from earlier stages of life in order to adapt to the environment HETEROCHRONY childhoodlike stage of life cycle becomes longer to fit new needs eg how to walk PLEIOTROPY when one gene affects several different phenotypic traits EVOLUNTIONARY NOVELTY being able to do new things lets the species fill out different roles eg swimming vs running ALLOMETRIC GROWTH organs grow in response to the amount of use over time in a species eg lots of running A bigger lungs ECOLOGICAL SPECIES CONCEPT defines species as a set of organisms making use of a single niche BIOLOGICAL SPECIES CONCEPT individuals can only produce healthy children with a mate from their own species COMPARATIVE EMBRYOLOGY similar stages in development ontogeny in related species A help establish evolutionary relationships mmgmz HOMOLOGY similarity resulting from common ancestry explained by descent with modification despite different functions can be explained with evolutionary trees gt hypotheses about the relationships between different groups can be made using different types of data eg anatomical amp DNA sequence data CONVERGENT EVOLUTION evolution of similar analogous features in distantly related groups due to adaptations VESTIGAL STRUCTURES remnants of features that served important functions in organism39s ancestors A no longer used COMPARATIVE ANATOMY Homologous structures A body parts that resemble one another in different species due to a common ancestor Qgt different appearance but resemble one another in how they are put together Analogous structures A body parts that resemble one another in different species due to adaptation MOLECULAR BIOLOGY closely related species share higher percentages of nucleotide amp amino acid sequences of DNA than distantly related species all living things share same genetic code GRADUALISM Hutton amp Lyell A changes in Earth39s surface can result form slow continuous actions still operating today UNIFORMITARIANISM mechanisms of change are constant over time ADAPTATION organisms change according to their environment new species A gradual accumulation of adaptation to different environments increase an individual s fitness A ability to survive NATURAL SELECTION quotsurvival of the fittest cause of adaptive evolution differences in survival amp reproduction among individuals as a result from interaction with the environment can increase or decrease allele frequencies due to environmental impact Darwin39s arguments for evolution Qgt All species are capable of producing more offspring than the environment can support Populations tend to remain stable in size except for seasonal fluctuations Resources are limited Individuals compete for survival There is variation among individuals in a population Much variation is heritable Only the most fit individuals survive Evolution occurs as favourable traits accumulate in the population 5555556 STABILISING SELECTION eliminates individuals with extreme or unusual traits most common trait best adapted middle ground DIRECTIONAL SELECTION favours traits at one extreme range of traits favoured traits can become more amp more extreme A change in allele frequencies DISRUPTIVE SELECTION DIVERSIFYING SELECTION favours extreme or unusual traits A both ends of the spectrum common traits are selected against SEXUAL SELECTION differential mating of animals in a population females can increase their fitness by increasing quality of offspring males can increase their fitness by increasing the quantity of offspring Male competition A contests of strength that award mating opportunities to the strongest male Female choice A traits or behaviours attractive to females often leads to sexual dimorphism A difference in the appearance of males amp females can be disruptive ARTIFICIAL SELECTION form of directional selection carried out by humans eg dog breeding SOURCES OF VARIATION Sexual reproduction A new combinations of alleles genetic recombination Qgt Crossing over A exchanges of DNA between nonsister of homologous chromosomes during prophase I of meiosis Qgt Independent assortment of homologues A daughter cells with random combinations of maternal amp paternal chromosomes are made during metaphase I Qgt Random ioining of gametes during fertilisation A contributes to the diversity of the gene combinations in the zygote Diploidy A presence of 2 copies of each chromosome in a cell A recessive alleles can be hidden in heterozygous individuals Aneuploidy A abnormal number of chromosomes extra or missing A can lead to birth defects Outbreeding A mating with unrelated partners Balanced polymorphism A maintenance of different phenotypes in a population Qgt Heterozygote advantage A heterozygous condition has a greater advantage than either homozygous condition Qgt Hybrid vigour Heterosis A superior quality of offspring resulting from2different inbred strains of plants Qgt Frequency dependent selection Minority advantage A least common phenotypes have a selective advantage A phenotypes alternate between low amp high frequencies MUTATIONS changes in the genetic code of an organism provide raw material for new variation amp can invent new alleles usually deleterious A harmful NEUTRAL VARIATION variation without selective value eg fingerprints GENE FLOW introduction or removal of alleles from a population when individuals leave or enter emigration amp GENETIC DRIFT random increase or decrease in alleles Founder effect A small group from population of origin has different allele frequencies Qgt Bottleneck effect A population undergoes dramatic decrease in size A change in allele frequencies NONRANDOM MATING individuals choose mates based upon their particular traits may also occur if mates only choose nearby individuals Inbreeding A mating with relatives Sexual selection A females choose males based upon appearance behaviour etc Qgt Qgt GENETIC EQUILIBIRUM HARDYWEINBERG EQUILIBRIUM allele frequencies in a population remain constant from generation to generation no evolution is occurring Must meet following conditions No natural selection A all traits selectively neutral Mutations don t occur No gene flow A isolated from other populations gt Qgt No genetic drift A population is large Qgt Mating is random Determined by evaluating following values Allele frequencies for each allele p q gt Qgt Frequency of homozygotes p2 qz Qgt Frequency of heterozygotes 2pq not obeyed in most natural populations but serves as a starting point to reveal how allele frequencies are changing AVERAGE HETEROZYGOSITY measures the average percent of loci that are heterozygous in a population SPECIES group of individuals capable of interbreeding SPECIATION formation of new species Allopatric speciation A population divided by a geographic barrier so that interbreeding is prevented Qgt A evolve separately due to natural selection Qgt Sympatric speciation A formation of new species without the presence of a geographic barrier Balanced polymorphism A individuals are reproductively isolated from other subpopulations A gene pools diverge Polyploidy A having more than the normal 2 sets of chromosomes in diploid Zn cells as a result of nondisjunction of all chromosomes during meiosis Hybridisation A2distincty different forms of a species mate along a geographic boundary called a hybrid zone A hybrids eventually diverge from parent populations Qgt Adaptive radiation A relatively rapid evolution of many species from a single ancestor when ancestral species is introduced to an area with diverse geographical or ecological conditions PREZYGOTIC ISOLATING MECHANISMS mechanisms that prevent fertilisation Habitat isolation A species don t encounter one another due to where they live Temporal isolation A species mate or flowers during different seasons or times of day Qgt Behavioural isolation A species don t recognise other species as mates due to differences in courtship rituals release of pheromones mating songs etc Qgt Mechanical isolation A male amp female sexual structures are incompatible Qgt Gametic isolation A male gametes don t survive in the environment of the female gamete eg internal fertilisation or female gametes don t recognise male gametes POSTZYGOTIC ISOLATING MECHANISMS mechanisms that prevent formation of fertile progeny Hybrid inviabilitv A zygote fails to develop properly amp aborts before reaching reproductive maturity Hybrid sterility A zygote become a functional adult but is reproductively sterile gt Qgt Hybrid breakdown A hybrids produce offspring with reduced viability or fertility DIVERGENT EVOLUTION two or more species originate from a common ancestor amp become increasingly different over time may be a result of allopatric speciation sympatric speciation or adaptive radiation CONVERGENT EVOLUTION two unrelated species share similar traits due to similar ecological conditions PARALLEL EVOLUTION two related species or lineages have made similar evolutionary changes after divergence from a common ancestor COEVOLUTION evolution of one species in response to new adaptation that appear in another species eg predator amp prey PHYLETIC GRADUALISM says that evolution occurs by gradual accumulation of small changes PUNCTUATED EQUILIBRIUM says that evolution consists geologically long periods of time with little or no evolution interrupted by short period of rapid evolution TAXONOMY ordered division amp naming of organisms HIERARCHICAL CLASSIFICATION Linnaeus introduced this Qgt Kingdom phylum class order family genus species PHYLOGENETIC TREES evolutionary relationships depicted in branching diagrams A show patterns of descent amp common ancestry Branch point A represents divergence of2species Sister taxa A groups that share an immediate common ancestor Rooted tree A includes a branch to represent the last common ancestor of all taxa in tree Polytomy A branch from which more than2groups emerge Phylograms A length of branch reflects number of genetic changes Ultrametric A length of branch reflects amount of time 4gt 5556 CLADE group of species that includes an ancestral species amp all its descendants within a tree Monophyletic A valid clade consists of ancestor species amp all descendants gt Qgt Paraphyletic A consists of an ancestral species amp some but not all descendants Qgt Polyphyletic A consists of various species that lack a common ancestor SHARED ANCESTRAL amp DERIVED CHARACTERS character that originated in an ancestor of the taxon eg backbones evolutionary novelty unique to a particular clade eg hair MAXIMUM PARSIMONY assumes that the tree with the few evolutionary events is the most likely MAXIMUM LIKELIHOOD a tree can be found that reflects the most likely sequence of evolutionary events GENE DUPLICATION amp DUPLICATED GENES increases the number of genes in a genome A more opportunities for evolutionary change Qgt Orthologous found in a single copy in the genome homologous between species passed in a straight line from generation to generation ended up in different gene pool due to speciation can diverge only after speciation occurs Qgt Paralogous result from gene duplication A more than one copy in genome can diverge within the clade that carries them often evolve new functions HORIZONTAL GENE TRANSFER movement of genes from one genome to another Qgt transposable elements amp fusion of organisms CLINE graded change in a trait along a geographic axis geographic variation CHEMICAL EVOLUTION describe processes that are believed to have contributed to the origin of life HETEROTROPH THEORY the first cells were heterotrophs A incapable of making own food ORIGIN OF LIFE Earth amp its atmosphere formed primordial atmosphere consisted of CO CO2 H2 N2 H2O S HCI amp HCN amp little or no O2 Primordial seas formed Earth cooled A gases condensed to produce primordial seas consisting of water amp minerals Complex molecules were synthesised Energy catalysed formation of organic molecules from inorganic molecules A organic quotsoup Energy provided mostly by UV light but also lightning radioactivity amp heat Qgt Complex molecules included acetic acid formaldehyde amp amino acids A later serve as monomers unit building blocks for the synthesis of polymers Qgt Oparin amp Haldane independently theorised that simple molecules could only form because oxygen was absent A would have prevented formation of organic molecules by supplanting most reactants in chemical reactions Stanley Miller tested these theories A simulated primordial conditions Polymers amp sef repicating molecules were synthesised monomers combined A polymers some of these reactions may have occurred by dehydration condensation A polymers formed by monomers by removal of water molecules Qgt LWOMS A abiotically produced polypeptides Organic molecules were concentrated amp isolated into protobionts Protobionts A precursors of cells that could carry out chemical reactions enclosed within a border across which materials could be exchanged but couldn t reproduce Microspheres amp coacervates A experimentally amp abiotically produced protobionts that have some selectively permeable qualities Primitive heterotrophic prokaryotes formed Qgt Heterotrophs A organisms that obtain energy by consuming organic substances Qgt organic quotsoup A source of organic material for heterotrophic cells Primitive autotrophic prokaryotes formed mutation A heterotroph could produce own food A autotroph manufacture own organic compounds using light energy or energy from inorganic substances Oxygen amp the ozone layer formed amp abiotic chemical evolution ended autotrophic activity A oxygen released A accumulated in atmosphere A interacted with UV light A Qgt Qgt 4gt 4gt gt ozone layer Qgt incoming UV light absorbed A major source of energy for abiotic synthesis of organic molecules terminated Eukaryotes formed endosymbiotic theory ENDOSYMBIOTIC THEORY eukaryotic cells originated from a mutually beneficial association between various types of prokaryotes mitochondria chloroplasts etc A establish themselves inside another prokaryote A eukaryote Evidence includes Mitochondria amp chloroplasts have their own DNA Ribosomes of mitochondria amp chloroplasts resemble those of bacteria amp cyanobacteria Mitochondria amp chloroplasts reproduce independently of their eukaryotic host binary fissionesque Mitochondria amp chloroplasts have2membranes both phospholipid bilayers Thylakoid membranes of chloroplasts resemble photosynthetic membranes of cyanobacteria 4gt 556 Cell Processes lntrogction to Metzgoolism METABOLISM totality of an organism39s chemical reactions emergent property of life that arises from interactions between molecules within the cell METABOLIC PATHWAY begins with a specific molecule amp ends with a product each step is catalysed by a specific enzyme Catabolic pathways release energy by breaking complex molecules A simpler compounds Anabolic pathways consume energy to build complex molecules from simpler ones 4gt BIOENERGETICS study of how organisms manage their energy resources ENERGY capacity to cause change can change from one form to another Kinetic energy A associated with motion gt Heat thermal energy A kinetic energy associated with random movement of atoms or molecules Qgt Potential energy A energy that matter possesses because of its location or structure Chemical energy A potential energy available for release in a chemical reaction THERMODYNAMICS study of energy transformations FREE ENERGY energy that can do work where temperature amp pressure are uniform eg in a living cell measure of a system39s instability A tendency towards a stable state EXERGONIC amp ENDERGONIC REACTIONS proceeds with net release of free energy spontaneous eg breakdown of organic molecules absorbs free energy from its surrounding nonspontaneous ENERGY COUPLING use of an exergonic process to drive an endergonic one used by cells to manage energy resources usu mediated by ATP WORK chemical transport or mechanical in cells ATP ADENOSINE TRIPHOSPHATE cell39s energy shuttle composed of ribose a sugar adenine a nitrogenous base amp 3 phosphate groups drives endergonic reactions by phosphorylation A transfer of a phosphate group to another molecule CATALYST chemical agent that speeds up a reaction without being consumed by it Qgt Enzymes are catalytic proteins FREE ENERGY ACTIVATION ACTIVATION ENERGY initial energy needed to start a chemical reaction often supplied in the form of heat from the surroundings SUBSTRATE reactant that an enzyme acts on enzyme binds to substrate A enzyme substrate complex active site A where enzyme binds to substrate Qgt Qgt COFACTORS nonprotein enzyme helpers may be inorganic eg ionic form of a metal or organic Qgt Organic A coenzyme includes vitamins COMPETITIVE amp NONCOMPETITIVE INHIBITORS bind to the active site of an enzyme A compete with substrate bind to another part of an enzyme A change shape A less effective active site eg toxins poisons pesticides antibiotics ALLOSTERIC REGULATION occurs when a regulatory molecule binds to a protein at one site amp affects the protein39s function at another site may either inhibit or stimulate an enzyme s activity Qgt Cooperativity A form of allosteric regulation that can amplify enzyme activity Cellt r Respiration AEROBIC RESPIRATION consumes organic molecules amp O2 A yields ATP Qgt Anaerobic respirationA similar to aerobic but consumes compounds other than O2 CELLULAR RESPIRATION includes both aerobic amp anaerobic respiration usu refers to aerobic Sugar Oxygen A Carbon dioxide Water Energy Three stages A glycolysis citric acid cycle Krebs cycle amp oxidative phosphorylation OXIDATIONREDUCTION REACTIONS REDOX REACTIONS chemical reactions that transfer electrons between reactants Oxidation A substance loses electrons is oxidised Reduction A substance gains electrons is reduced Reducing agent A electron donor Oxidising agent A electron receptor 4gt Qgt Qgt Qgt GLYCOLYSIS decomposition of glucose to pyruvate pyruvic acid 4 main steps 2 ATP added that are converted to ADP A changes glucose in preparation of subsequent steps 2 NADH produced A NADH coenzyme forms when NADquot combines with 2 energyrich electrons amp H obtained from an intermediate molecule during the breakdown of glucose A energyrich molecule Qgt 4 ATP produced Qgt 2 pyruvate formed KREBS CYCLE CITRIC ACID CYCLE TRICARBOXYLIC ACID TCA CYCLE details what happens to pyruvate Qgt Krebs cycle describes what happens to 1 but 2 pyruvate are produced in glycolysis 2 main steps Before Krebs Pyruvate to acetyl CoA gt pyruvate combines with coenzyme A CoA to produce acetyl CoA 1 NADH amp 1 CO2 are also produced Qgt Krebs Cycle 3 NADH 1 FADH2 1 ATP CO2 acetyl CoA combines with OAA oxaloacetate to form citrate citric acid 3 NADH amp 1 FADH2 coenzyme A accepts electrons are made CO2 is released CO2 produced A exhaled by animals when they breathe OXIDATIVE PHOSPHORYLATION process of extracting ATP from NADH amp FADH2 occurs when a phosphate group is added to ADP to form ATP A electrons in the electron transport chain supply energy to generate H gradient A energy for ATP synthase to generate ATP from ADP amp a phosphate group Electrons from NADH amp FADH2 pass along an electron transport chain consists of proteins that pass these electrons from one carrier protein to the next some carrier proteins such as cytochromes include nonprotein parts containing iron Qgt along each step of the chain electrons give up energy used to phosphorylate ADP A ATP Qgt NADH provides electrons that have enough energy to generate about 3 ATP while FADH2 produces about 2 ATP Qgt the final electron acceptor oxygen A accepts the 2 electrons A forms water Qgt cytochrome c A carrier protein that is ubiquitous among organisms MITOCHONDRIA where Krebs cycle amp oxidative phosphorylation occur 4 distinct areas Outer membrane Qgt consists of double layer of phospholipids Qgt intermembrane space narrow area between inner amp outer membaranes where protons accumulate in the form of H ions Qgt Inner membrane a double phospholipid bilayer has convolutions called cristae sing crista oxidative phosphorylation occurs here A electron transport chain transports H ions from the matrix to the intermembrane space Matrix fluid material that fills the area inside the inner membrane Krebs cycle occurs here CHEMIOSMOSIS mechanism of ATP generation A occurs when energy is stored in the form of a proton concentration gradient across a membrane Five main steps Krebs cycle produces NADH amp FADH2 in the matrix CO2 also generated substratelevel phosphorylation occurs to produce ATP Electrons are removed from NADH amp FADH2 Protein complexes in the inner membrane remove electrons from these molecules A electrons move along electron transport chain from one protein complex to the next H ions protons are transported from the matrix to the intermembrane compartment Protein complexes transport H ions from the matrix across the inner membrane amp to the intermembrane space A pH amp electrical gradient across the inner membrane is created H transferred to intermembrane space A pH decreases in the intermembrane space increases in the matrix 0 increases further as electrons at the end of the electron transport chain combine with H amp oxygen A water lead to proton pH amp electrical charge voltage gradients A potential energy reserves ATP synthase generates ATP ATP synthase A channel protein in the inner membrane 0 allows protons in the intermembrane compartment to flow back into the matrix A protons flowing back generate energy for ATP synthase to generate ATP 4gt 5 5 5 5 SUBSTRATE LEVEL PHOSPHORYLATION occurs when a phosphate group amp its associated energy is transferred to ADP to form ATP substrate molecule molecule with phosphate group donates the high energy phosphate group occurs during glycolysis ALCOHOL FERMENTATION form of anaerobic respiration that occurs in plants fungi amp bacteria 2 steps Pyruvate to acetaldehyde For each pyruvate 1 CO2 amp 1 acetaldehyde are produced A CO2 formed is source of carbonation in fermented drinks Acetaldehyde to ethanol Energy in NADH used to drive reaction A release of NAD For each acetaldehyde 1 ethanol is made amp 1 NAD produced goal of pathway is to free NADquot to allow glycolysis to continue 4gt 4gt LACTIC ACID FERMENTATION pyruvate is converted to lactate lactic acid A NADH gives up its electron to form NADquot in the process A can now be used for glycolysis humans amp other mammals A lactate transported to liver A converted back to glucose when surplus ATP is available 4gt Photosvnthesis PHOTOSYNTHESIS process of converting energy in sunlight to energy in chemical bonds especially glucose 6CO2 6H2O light A C8H22O8 602 reverse of cellular respiration with different energy source Begins with ight absorbing pigments in plant cells A pigment molecule able to absorb the energy from light only within a narrow range of wavelengths A different pigments capable of absorbing different wavelengths act together Include green chlorophyll a amp chlorophyll b amp cartenoids red orange or yellow 0 Light is absorbed A energy from light incorporated into electrons within atoms that make up the molecule A energised electrons unstable amp almost immediately re emit absorbed energy A energy reabsorbed by electrons of a nearby pigment molecule A process continues 0 Process ends when energy is absorbed by either a E or E700 chlorophyll a molecule numbers represent the wavelengths at which they absorb the maximum amount of light A different from other chlorophyll molecules because of their association with various nearby pigments P700 with other pigments A pigment cluster called photosystem I PSI P880 with other pigments A pigment cluster called photosystem II PSII NONCYCLIC PHOTOPHOSPHORYLATION process of making ATP from ADP amp P using energy derived from light all of its reactions require light A ight dependent reactions H20 ADP P2 NADP light A ATP NADPH 02 H begins with PS II amp follows 7 steps PS II Electrons trapped by P880 in PII are energised by light Primary electron acceptor t5 2 energised electrons trapped by P880 in PII are passed to a molecule called the primary electron acceptor first in a chain of electron acceptors Electron transport chain Electrons pass through an electron transport chain A consists of proteins that pass electrons from one carrier protein to the next 0 Ferrodoxin amp cytochrome A carrier proteins that include nonprotein parts containing iron Analogous to chains in oxidative phosphorylation 0 Phosphorylation 2 electrons move quotdown electron transport chain A lose energy 0 Energy lost is used to phosphorylate about 15 ATP molecules Photosystem I Electron transport chain terminates with PS I with P700 A electrons energised by sunlight again A passed to a different primary electron acceptor NADPH 2 electrons pass through a short electron transport chain A at the end of the cahain they combine with NADP amp H to form NADPH coenzyme energyrich Splitting of water 2 electrons that originated in PS II incorporated into NADPH A loss of these electrons from PS II replaced when H2O is split into 2 electrons 2 H3939 amp 2 O2 0 Manganesecontaining protein complex catalyses reaction 0 2 electrons replace lost electrons from PS II one H provides H in NADPH 2 O2 contributes to released oxygen gas CYCLIC PHOTOPHOSPHORYLATION second sequence occurs when electrons energised in PS I are recycled energised electrons form PS I join with protein carriers amp generated ATP as they pass along the electron transport chain A return to PSI A energised again to participate in cyclic or noncyclic photophosphorylation occurs simultaneously with noncyclic photophosphorylation 2 electrons passing through generate about 1 ATP CALVIN CYCLE CARBON REDUCTION CYCLE C3 CYCLE quotfixes CO2 A takes chemically unreactive inorganic CO2 amp incorporates it into an organic molecule that can be used in biological systems function of pathway is to produce a single molecule of glucose A must repeat 6 times amp use 6 CO2 molecules ight independent reaction A does not directly use light 6CO2 18ATP 12 NADPH H A 18ADP 12NADPquot C5H12O5 glucose 4 main steps Carboxylationz 6CO2 combine with RuBP to produce 12 PGA the enzyme rubisco catalyses the merging of CO2 amp A ribulose biphosphate PGA phosphoglycerate is first product formed amp contains 3 carbon atoms A reason for alternate name of C3 photosynthesis Reduction 12 ATP amp 12 NADPH are used to convert 12 GPA to 12 GBP energy in ATP amp NADPH molecules incorporated into E A very energyrich molecule ADP Pi amp NADP are released amp then reenergised in noncyclic photophosphorylation Regeneration 6 ATP are used to convert 10 GBP to 6 RuBP regenerating the 6 RuBP originally used to combine with CO2 allows the cycle to repeat Carbohydrate synthesis The remaining 2 GBP are used to build glucose A combined to form disaccharides amp polysaccharides Other monosaccharides eg fructose amp maltose can also be formed 4gt 4gt 4gt 4gt CHLOROPLASTS sites where both ight dependent amp ight independent reactions of photosyntehsis occur contain 6 areas Outer membrane like the plasma membrane consists of a double layer of phospholipids Intermembrane space Qgt narrow area between inner amp outer membranes Qgt Inner membrane second membrane double phospholipid bilayer L Wei fluid material that fills the area inside the inner membrane Calvin cycle occurs here mm suspended within the stroma pancakelike membranes A individual membrane layer entire stack A granum pl grana 0 membranes contain protein complexes including photosystems PS I amp PS II cytochromes amp other electron carriers of ight dependent reactions Thylakoid lumen inside of thylakoid where H ions accumulate CHEMIOSMOSIS IN CH LOROPLASTS mechanism of ATP generation that occurs when energy is stored in the form of a proton concentration gradient across a membrane analogous to ATP generation in mitochondria 4 main steps H ions accumulate inside thylakoids H released into the lumen of the thylakoids when water is split by PS II H carried from stroma A lumen by a cytochrome in the electron transport chain between PS ll amp PS I A pH amp electrical gradient across the thylakoid membrane is created H accumulates inside A pH decreases inside pH 5 increases outside the stroma pH 8 H positively charged A electrical voltage gradient ATP synthases generate ATP the pH amp electrical gradient represent potential energy channel proteins called ATP synthases allow H to flow through the thylakoid membrane amp out to the stroma A energy generated provides energy for ATP synthases to phosphorylate ADP to ATP 0 3 H A 1 ATP The Calvin cycle produces G3P using NADPH CO2 amp ATP end of electron transport chain following PS I A electrons combine with NADP amp H A NADPH NADPH ATP CO2 A 2 GBP generated A used to make glucose or other carbohydrates 4gt 4gt 4gt 4gt PHOTORESPIRATION rubisco is also able to fix oxygen A fixation of oxygen leads to reduced CO2 fixing efficiency A fixing both products formed when 02 is combined with RuBP are not useful A need to be broken down by peroxisomes specialised cellular organelles found near chloroplasts C4 PHOTOSYNTESIS instead of being fixed by rubisco into PGA CO2 combines with E to form E by being fixed with E carboxylase Qgt OAA has 4 carbon atoms A C4 OAA converted to malate A shuttled through plasmodesmata to bundle sheath cells A malate converted to pyruvate amp CO2 A pyruvate shuttled back to mesophyll cells where ATP is broken down into AMP to convert pyruvate back to PEP CO2 is spatially segregated increases efficiency of photosynthesis A little oxygen can reach bundle sheath cells reduced time when stomata are open A found in hot dry climates A advantage over C3 plants eg sugar canes CAM PHOTOSYNTHESIS crassulacean acid metabolism 4 parts PEP carboxylase fixes CO2 to OAA A converted to malic acid gt Qgt malic acid is shuttled to vacuole of cell Qgt stomata are open at night PEP carboxylase is active malic acid accumulates in ce s vacuole Qgt stomata are closed during the day A malic acid is shuttled out of the vacuole amp converted back to OAA requires 1 ATP A ADP A release of CO2 A fixed by rubisco A Calvin cycle proceeds CO2 is temporally segregated eg pineapples Cell Communication SIGNAL TRANSDUCTION PATHWAY series of steps by which a signal on a ce s surface is converted into a specific cellular response Sutherland A cells receiving signals go through reception transduction and response multistep pathways have the benefits of amplifying the signal via enzyme cascades more response and contributing to the specifity of the response may regulate the activity of enzymes affect physical characteristics of the cell eg cell shape the same signal can have different effects with different proteins and pathways LOCAL REGULATORS AND HORMONES used by animal cells to communicate over short distances used by plants and animals for ong distance signalling LIGAND signal molecule MEMBRANE RECEPTORS G protein coupled receptor Qgt works with the help of a G protein acts as an onoff switch if GDP is bound to G protein A inactive Receptor tyrosine kinases Qgt attach phosphates to tyrosines Qgt can trigger multiple signal transduction pathways at once Ligandgated ion channel Qgt acts as a gate when the receptor changes shape Qgt signal molecules binds as a ligand to the receptor A gate allows specific ions eg Naquot Ca2 through a channel in the receptor PROTEIN KINASES AND PROTEIN PHOSPHATASES transfer phosphates from ATP to protein A phosphorylation remove phosphates from proteins A dephosphorylation acts as molecular switch A turns activities on and off SECOND MESSENGERS small nonprotein water soube molecules or ions that spread throughout a cell by diffusion participate in pathways initiated by G protein coupled receptors and receptor tyrosine kinases cyclic AMP and calcium ions are common second messengers CYCLIC AMP cAM P AND ADENYLYL CYCLASE one of the most widely used second messengers A usu activates protein kinase A A phosphorylates various other proteins enzyme in the plasma membrane that converts ATP to cAMP in response to an extracellular signal CALCIUM IONS Ca2 act as second messengers in many pathways important A cells can regulate its concentration signal relayed by signal transduction pathway A may trigger increase in calcium in cytosol pathways leading to release of calcium involve insositol triophosphate IP3 and diacylglycerol DAG as additional second messengers CASPASES main proteases enzymes that cut up proteins that carry out apoptosis triggered extracellular deathsignalling ligand DNA damage in the nucleus protein misfolding in the endoplasmic reticulum 4gt SCAFFOLDING PROTEINS large relay proteins to which other relay proteins are attached can increase signal transduction efficiency by grouping together different proteins involved in the same pathway The Cell Cvcle CELL DIVISION reproduction of cell 2 phases A nuclear division cytokinesis division of material in nucleus division of cytoplasm unicellular organisms A division of one cell reproduces entire organism multicellular organisms depend of this for development from a fertilised egg growth and repair integral part of the cell cycle A life of a cell from formation to its own division SOMATIC CELLS AND GAMETES nonreproductive cells have 2 sets of chromosomes reproductive cells sperm and eggs have 1 set of chromosomes CHROMATIN complex of DNA and protein in eukaryotic cells that condenses during cell division A chromosomes SISTER CHROMATIDS two identical halves of each chromosome joined at the centromeres HOMOLGOUS CHROMOSOMES two copies of each chromosome A pair one from father one from mother INTERPHASE period during which the cell is not dividing chromatin in enclosed within a clearly defined nuclear envelope within the nucleus 1 or more nucleoli are visible outside the nucleus A 2 microtubule organising centres MTOCs centrosomes lie adjacent to one another in animals A each MTOC contains a pair of centrioles 4gt MITOSIS Prophase nucleoli disappear and chromatin condenses into chromosomes gt Qgt nuclear envelope breaks down Qgt mitotic spindle is assembled A begins as MTOCs move apart to opposite poles A microtubules develop from each MTOC increasing in length by the addition of tubulin units to the microtubule ends away from the MTOC microtubules from each MTOC connect to a kinetochore specialised region in centromere Qgt microtubules tug on kinetochore A chromosomes move back and forth Metaphase chromosomes distributed across metaphase plate plane lying between the 2 poles of the spindle ends when microtubules still attached to kinetochores pull each chromosome apart into 2 chromatids Term 2 Genes amp Heredity DNA Replication TRANSFORMATION change in genotype amp phenotype due to assimilation of foreign DNA BACTERIOPHAGE viruses that infect bacteria that are widely used in molecular genetics research CHARGAFF S RULES in any species the number ofA amp T bases will be equal amp the number of G amp C bases will be equal Qgt explained by the WatsonCrick model purines pair with pyridimines SEMICONSERVATIVE MODEL when a double helix replicates each daughter molecule will have one quotconserved strand amp one newly made strand proven by Matthew Meselson amp Franklin Stahl Qgt competing models gt conservative parent strands rejoin amp dispersive each strand is a mix of old amp new PROCESS OF DNA REPLICATION Helicase unwinds DNA producing a replication fork Singe strand binding proteins prevent the single strands of DNA from recombining Topoisomerase removes twists amp knots from that form in the doublestranded template as a result as helicaseinduced unwinding Primase initiates DNA replication at special nucleotide sequence origins of replication with short segments of RNA nucleotides RNA primers DNA polymerase attaches to the RNA primers amp begins adding DNA nucleotides to the complement strand Leading strand is assembled continuously as the DNA uncoils Lagging strand is assembled in short Okazaki fragments joined by DNA ligase RNA primers are replaced by DNA nucleotides ORIGIN OF REPLICATION where replication begins gt 2 DNA strands are separated amp open up a replication quotbubbe REPLICATION FORK a Y shaped region at the end of each replication bubble where new DNA strands are elongating HELICASES enzymes that untwist the double helix at the replication forks SINGLE STRAND BINDING PROTEIN binds to amp stabilises singlestranded DNA until it can be used as a template TOPOISOMERASE corrects quotoverwinding ahead of replication forks A breaks swivels amp rejoins DNA strands PRIMER short initial nucleotide RNA strand 510 nucleotides 3 end A starting point for new DNA strand PRIMASE enzyme that can start an RNA chain from scratch amp adds RNA nucleotides one at a time using parental DNA as a template DNA SYNTHESIS each nucleotide added A nucleoside triphophate E supplies adenine to DNA similar to ATP Qgt has deoxyribose ATP has ribose sugars each monomer of dATP joins A 2 phosphate groups lost as molecules of pyrophosphate Qgt breaking these bonds provides the chemical energy required for the process DNA POLYMERASE catalyses the elongation of new DNA at the replication fork cannot initiate synthesis of a polynucleotide A can only add nucleotides to the 3 end along a template strand of DNA A synthesises a leading strand continuously towards the replication fork ANTIPARALLEL 2 strands of DNA oriented in opposite direction nucleotides only added to free 3 end A can only elongate in 5 A 3 direction LEADING STRAND 3 5 strand where replication occurs continuously LAGGING STRAND 5 3 strand that is synthesised as a series of fragments Okazaki fragments which are joined by DNA ligase MISMATCH REPAIR repair enzymes correct errors in base pairing NUCLEOTIDE EXCISION REPAIR nuclease cuts out amp replaces damaged stretches of DNA TELOMERES nucleotide sequences at the end of eukaryotic chromosomal DNA molecules that postpone the erosion of genes TELOMERASE catalyses the lengthening of telomeres in germ cells DNA DAMAGE can be caused by chemical radioactive emissions X rays UV light amp certain molecules eg in cigarette smoke Protein Svnthesis GENE EXPRESSION the process by which DNA directs protein synthesis includes transcription amp translation ONE GENE ONE POLYPEPTIDE HYPOTHESIS each gene dictates the production of a specific polypeptide eg enzymes amp proteins PROTEIN SYNTHESIS process that describes how enzymes amp other proteins are made from DNA Qgt transcription RNA processing translation CELLULAR CHAIN OF COMMAND DNA A RNA A protein MESSENGER RNA mRNA a single strand of RNA that provides the template used for sequencing amino acids into a polypeptide form codons that read in the 5 3 direction based on the triplet code A 64 kinds 20 amino acids Qgt must be read in correct reading frame correct grouping in order for the specific polypeptide to be produced decoded by the genetic code TRANSFER RNA tRNA short RNA molecule that is used for transporting amino acids to their place on the mRNA template Qgt anticodon pairs with mRNA codon A wobble allows anticodon to basepair with more than one codon 3 end attaches to an amino acid RIBOSOMAL RNA rRNA building blocks of ribosomes A proteins rRNA large amp small ribosomal subunits Qgt ribosome coordinates activities of mRNA amp tRNA during translation Qgt 3 binding sites I Psjite A holds tRNA with polypeptide chain I Asjrce A holds tRNA with next amino acid I Esjrce A exit site where tRNAs leave RNA POLYMERASE main enzyme that catalyses the formation of RNA from the DNA template a sequence of nucleotides on the DNA molecule serves as a promoter region A where RNA polymerase complex binds moves along DNA in 5 3 direction PROMOTER sequence of DNA to which RNA polymerase attaches to A transcription TRANSCRIPTION first stage of gene expression RNA is synthesised under the direction of DNA as a template Qgt produces messenger RNA mRNA Consists of three stages Qgt Initiation I RNA polymerase attaches to a promoter region on the DNA amp begins to unzip the DNA into 2 strands I promoter region for mRNA transcription often contains a TATA box I transcription factors mediate binding of RNA polymerase amp initiation 0 transcription initiation complex A completed assembly of transcription factor amp RNA polymerase bond to promoter Qgt Elongation I RNA polymerase unzips the DNA amp assembles RNA nucleotides using one strand of the DNA as a template I elongation of RNA molecule occurs in 5 3 direction Qgt Termination I Bacteria A RNA polymerase reaches the end of the terminator I Eukaryotes A Polymerase continues transcription after pre m RNA is cleared from RNA chain amp eventually falls off PRIMARY TRANSCRIPT initial RNA transcript before RNA processing from any gene TEMPLATE STRAND provides a template for ordering the sequence of nucleotides in an RNA transcript mRNA PROCESSING both ends of the primary transcript are altered amp other interior parts are added or deleted before the molecule gets sent out for translation gt 9amp9 P PPG 5 I added to 5 end of mRNA I provides stability amp an attachment point for the smaller ribosomal subunit I protects mRNA from hydrolytic enzymes I facilitates export of mRNA gt Poy Atail A A A AA 3 I attached to 3 end of mRNA I provides stability I controls movement of mRNA across nuclear envelope I protects mRNA from hydrolytic enzymes I facilitates export of mRNA Qgt RNA splicing A small nuclear ribonucleus proteins snRNPs delete introns amp join extrons I Introns amp extrons A intervening noncoding regions express a code for a polypeptide Qgt Alternative splicing A some genes code for more than one polypeptide depending on which segments are treated as exons during RNA splicing I same RNA transcript different mRNAs can be produced SPLICEOSOMES a variety of proteins amp snRNPs that recognise splice sites DOMAINS discrete regions of a protein A different exons different domains Qgt exon shuffling A may result in new proteins RIBOZYMES catalytic RNA molecules that act as enzymes amp can splice RNA Qgt Properties that allow RNA to function as an enzyme I can from 3D structure I can base pair with itself I some bases contain functional groups I may hydrogenbond with other nucleic acid molecules TRANSLATION mRNA tRNA amp ribosomal subunits transported across nuclear envelope A cytoplasm correct match of amino acids attach to 3 end of tRNAs A aminaoacyltRNA energy for translation provided by E molecules Consists of three stages Qgt Initiation I small ribosomal subunit attaches to a special region near the 5 end of mRNA I tRNA anticodon UAC attaches to mRNA at start codon AUG I nitration factors bring in large ribosomal subunit to complete translation initiation complex I complete ribosome formed with tRNA occupying the P site Qgt Elongation I next tRNA bearing an amino acid binds to the A site of the ribosome I previous amino acid picked up A eventual chain I previous tRNA leaves via E site I remaining tRNA translocates from A site to P site Qgt Termination I stop codon enters A site I release factor accepted protein A water added instead of amino acid I translation initiation complex breaks apart A parts released I polypeptide by receive more processing by the ER or a Golgi body before being used or sent out of the cell SIGNAL PEPTIDE mark polypeptides A ER or secretion Qgt bound byto signal recognition particles SRP POLYRIBOSOM ES POLYSOM ES when more than one ribosome translates a single mRNA at the same time itations amp l2NA Organisation MUTATION any sequence of nucleotides that doesn t exactly match the original DNA molecule from which it was copied change in genetic material of a cell or virus POINT MUTATION change in a single nucleotide of a gene Qgt Substitution A An incorrect nucleotide takes the place of a correct one Qgt Deletion A A nucleotide is omitted from the sequence Qgt Insertion A A nucleotide is added to the sequence I Frameshift mutation A Altered reading frame due to insertion or deletion SILENT MUTATION new codon still codes for the same amino acid due to wobble MISSENCE MUTATION new codon codes for a new amino acid NONSENSE MUTATION new codon codes for a stop codon MUTAGENS physical or chemical agents that cause mutations Qgt Carcinogens A mutagens that activate uncontrolled cell growth cancer PROOFREADING DNA polymerase checks each new nucleotide with the template strand MISMATCH REPAIR enzymes repair errors that escape proofreading of DNA polymerase EXCISION REPAIR enzymes remove nucleotides damaged by mutagens Qgt complementary strand of damaged strand used as a template to repair error CHROMATIN matrix of DNA packaged with proteins in eukaryotes HISTONES proteins responsible for the first level of DNA packing in chromatin Qgt adding methyl groups A condenses Qgt adding phosphate groups A loosens Qgt adding acetyl groups acetylation to positively charged lysines in tails A loosens amp promotes initiation of transcription NUCLEOID DNA is quotsupercoied amp found here in bacterium NUCLEOSOM ES beadlike DNA histone complexes EUCHROMATIN DNA is loosely bound to nucleosomes DNA in these regions A actively transcribed HETEROCHROMATIN nucleosomes are tightly compacted A DNA is inactive stains darker than euchromatin forms centromeres amp telomeres TRANSPOSONS JUMPING GENES transposable genetic elements that can move to a new location on the same or a different chromosome A effect of a mutation may consist only of DNA that code for an enzyme that enables it to be transported or contain genes that invoke replication of the transposon Molecular Cjenetics of Viruses amp I3acteria BACTERIOPHAGES viruses that only attack bacteria NUCLEIC ACID either RNA or DNA that contains the hereditary information of the virus either double or singlestranded CAPSID protein coat that encloses the nucleic acid assembled form capsomeres VIRAL ENVELOPES surround the capsids of some viruses amp incorporate phospholipids amp proteins from the cell membrane of the host LYTIC CYCLE phage reproductive cycle where the host s cell wall is digested virus that only produces with this cycle A virulent phage LYSOGENIC CYCLE viral DNA temporarily incorporated into the DNA of the host cell Qgt dormant stage A prophage bacteria provirus virus also involved in retrovirus life cycle inactive until triggered by a stimulus A lytic cycle RESTRICTION ENZYMES recognise amp cut up certain phage DNA RETROVIRUSES ssRNA viruses that use reverse transcriptase to make a DNA complement of their RNA Qgt manufacture RNA immediately or begin lysogenic cycle VIROIDS circular RNA molecules that infect plants amp disrupt their growth PRIONS sow acting virtually indestructible infectious proteins that cause brain diseases in mammals BINARY FISSION chromosomes replicate amp cell divides into 2 cells PLASMIDS short circular DNA molecules outside the chromosomes Qgt episomes can be incorporated into the bacterial chromosome CONJUGATION DNA exchange between bacteria pilus pl pili connect with recipient bacterium gt chromosomal or plasmid DNA sent to recipient F amp R PLASMIDS contains the genes that enable bacteria to produce pili provide bacteria resistance against antibiotics TRANSDUCTION new DNA is introduced into the genome of a bacterium by a virus TRANSFORMATION bacteria absorbs DNA from their surroundings amp incorporates it into its genome Qgt facilitate by specialised proteins on the cell membrane of some bacteria Regulation of Gene Expression OPERON unit of DNA that controls transcription of a gene that contains the promoter operator structural genes amp regulatory gene OPERATOR can block the action of RNA polymerase if occupied by a repressor protein STRUCTURAL GENES contain DNA sequences that code for several related enzymes that direct the production of some particular end product REGULATORY GENE lies outside the operon region amp produces repressor proteins Qgt occupy the operator region amp block action of RNA polymerase ACTIVATOR PROTEINS produced by regulatory genes that assist in attachment of RNA polymerase to the promoter region COREPRESSOR molecule that cooperates with a repressor protein gt switch an operon off INDUCIBLE ENZYMES produced by the operon substance required to induce the operon eg lactose with lac operon in Ecoli REPRESSIBLE ENZYMES structural genes stop producing enzymes in the presence of an active repressor eg trp operon in E coli REGULATORY PROTEINS repressors amp activators influence how readily RNA polymerase will attach to a promoter region A numerous activators influence transcription NUCLEOSOME PACKING influences whether a section of DNA will be transcribed Qgt methylation A harder Qgt acetylation of histones A uncoiling amp transcription RNA INTERFERENCE short interfering RNAs block mRNA transcription or translation or degrade existing mRNA A prevents transcription Qkarvotic Cjenomes GENOMIC IMPRINTING methylation regulates expression of either maternal or paternal alleles of certain genes at the start of development CONTROL ELEMENTS segments of noncoding DNA that regulate transcription by binding certain proteins critical to precise regulation of gene expression in different cell types ENHANCERS distal control elements may be far away from gene or in an introns PROXIMAL CONTROL ELEMENTS located close to the promoter PROTEASOMES giant protein complexes that bind protein molecules amp degrade them ONCOGENES cancer causing genes PROTO ONCOGENES corresponding normal cellular genes A normal cell growth amp division Qgt converted by movement of DNA amplification point muations TUMOURSUPPRESSOR GENES help prevent uncontrolled cell growth Qgt repair damaged DNA control cell adhesion inhibit cell cycle in cellsignalling pathway MUTATION IN ras amp p53 GENES hyperactive Ras protein A increased cell division prevent suppression of cell cycle A normally prevents passing on of mutations MICRORNAS small singlestranded RNA molecules that can bind to mRNA A degrade mRNA or block its translation Recombinant DNA amp Biotechnology GENE CLONING using bacteria to make multiple copies of a gene RECOMBINANT DNA contains DNA segments or genes from different sources RESTRICTION ENZYMES from bacteria A usu used to combat invading viruses very specific A DNA cut at specific recognition sequences of nucleotides restriction sites usually staggered yield restriction fragments STICKY END 5 OVERHANG unpaired extension resulting from cutting double stranded DNA VECTOR amp CLONING VECTOR fragment of foreign DNA being introduced original plasmid GEL ELECTROPHORESIS DNA fragments of different lengths are separated by length shorter farther as they diffuse through a gel under the influence of an electrical field SINGLE NUCLEOTIDE POLYMORPHISMS single basepair sites that vary in a population Qgt result in restriction fragment length polymorphisms RESTRICTION FRAGMENT LENGTH POLYMORPHISMS fragments between individuals of the same species differ in length due to slight differences in DNA sequences SHORT TANDEM REPEATS short sequences of nucleotides 25 base pairs that repeat multiple times Qgt number of repeats varies among individuals COMPLEMENTARY DNA cDNA DNA obtained directly from mRNA that codes for the desired polypeptide with reverse transcriptase from retroviruses POLYMERASE CHAIN REACTION PCR using synthetic primers that initiate replication at specific nucleotide sequences exponential growth in replication can be triggered with rapid heating followed by rapid cooling GENOMIC LIBRARY collection of recombinant vector clones produced by cloning DNA fragments from an entire genome BACTERIAL ARTIFICIAL CH ROMOSOME large plasmid that has been trimmed down A can carry large DNA insert NUCLEIC ACID PROBE used to identify clone carrying gene of interest A has sequence complementary to the gene Qgt process is nucleic acid hybridisation EXPRESSION VECTOR cloning vector with a highly active prokaryotic promoter ELECTROPORATION applying a brief electric pulse to create temporary holes in plasma membranes A insertion of recombinant DNA into eukaryotic cells RESTRICTION FRAGMENT ANALYSIS DNA fragments produced by restriction enzyme digestion A sorted by gel electrophoresis SOUTHERN BLO39I39I39ING gel electrophoresis of DNA fragments amp nucleic acid hybridisation NORTHERN BLOTI39ING gel electrophoresis of mRNA A hybridisation with a probe on a membrane A compare mRNA of different developmental stages REVERSE TRANSCRIPTASE POLYMERASE CHAIN REACTION mRNA amp reverse transcriptase combined to make cDNA A run on gel A mRNA of interest identified DNA MICROARRAY ASSAYS compare patterns of gene expression in different tissues times or conditions IN VITRO MUTAGENESIS mutations introduced to a cloned gene A alters or destroys function TRANSGENIC animals or plants with genes introduced from other species E brvonic Development EMBRYONIC DEVELOPMENT a singlecelled zygote A different cell types tissues A organs A organ systems A organism orchestrated by gene expression NUCLEAR TRANSPLANTATION nucleus of an unfertilised egg cell A replaced with nucleus of a differentiated cell A norma development TOTI POTE NT cell that can generate a complete new organism PLURIPOTENT stem cells that can give rise to multiple but not all cell types STEM CELL relatively unspecialised cell that can reproduce itself indefinitely amp differentiate into specialised cells of one or more types esp embryonic CELL DETERMINATION cell is committed to its final fate precedes differentiation involves expression of genes for tissuespecific proteins CELL DIFFERENTIATION production of tissuespecific proteins to become specific types of cells CYTOPLASMIC DETERMINANTS maternal substances in egg that influence early development INDUCTION signal molecules from embryonic cells cause transcriptional changes in nearby target cells leads to specialised cell types EMBROYNIC LETHALS embryos with lethal mutations eg legs in head MATERNAL EFFECT GENES EGGPOLARITY GENES control orientation of egg gt organism MORPHOGENS gradient of substances establish an embryo s axes amp other features Qgt in relation to the gradient hypothesis SEGMENTAITON GENES produce proteins gt direct formation of segments after major body axes are formed APOPTOSIS programmed cell death via cell signalling eg human hands PATTERN FORMATION development of spatial organisations of tissues amp organs Qgt occurs continually in plants mostly embryos amp juveniles in animals POSITIONAL INFORMATION molecular cues that control pattern formation Qgt tell a cell its location relative to axes amp other cells Biological Interactions The Historv of Life on Earth PROTOBIONTS aggregates of abiotically produced molecules surrounded by a membrane or membranelike structure that exhibit simple reproduction amp metabolism chemical homeostasis RIBOZYMES RNA molecules that catalyse reactions eg making complementary copies of short stretches of their own sequence or other short pieces of RNA STRATA layers of sedimentary rock where fossils can be found RADIOMETRIC DATNIG parent isotope decays to daughter isotope at a constant rate A determine age HALFLIFE time required for half of parent isotope to decay GEOLOGIC RECORD split into Archaen Proterozoic amp Phanenerozoic eras Qgt Phanenerozoic era A multicellular life STROMATOLITES 35 billion year old fossils oldest known rocklike structure made of many layers of bacteria amp sediment OXYGEN REVOLUTION likely caused by cyanobacteriaesque organisms organisms 2722 billion years ago opportunity to gain energy from light organisms A exploit new ecosystems ENDOSYMBIOSIS oldest eukaryotes A 21 billion years mitochondria amp plastids A formerly small prokaryotes within larger host cells Qgt endosymbionts are the ones inside Qgt similarities in inner membrane own DNA ribosomes are prokaryotesque SERIAL ENDOSYMBIONTS mitochondria evolved before plastids through a series of events quotSNOWBALL EARTH suggests that glaciation confined life to equatorial regiondeepsea vents 535325 million years ago CONTINENTAL DRIFT Earth39s plates move slowly over the mantle A plates can collide separate slide past each other quotlong fuse PANGAEA shape of Earth39s continents 11 billion 600 million amp 250 million years ago quotall earth Qgt recent one had shallow water habitat colder amp drier inland global cooling when it broke up A allopatric speciation MASS EXTINCTION rate of extinction increases dramatically A major geological boundaries ADAPTIVE RADIATION common ancestor A diversely adapted species I3acteria amp Archaea PEPTIDOGLYCAN network of sugar polymers crosslinked by polypeptides in bacterial cell walls Qgt archaea have polysaccharides amp protein inside instead GRAMPOSITIVE amp GRAMNEGATIVE groups of bacteria based on cell wall composition Qgt negative A less peptidoglycan toxic outer membrane more antibiotic resistance CAPSULE polysaccharide or protein layer that covers many prokaryotes FIMBRIAE attachment pili A prokaryotes can stick to substrate or other individuals in colony SEX PILI longer than fimbriae allow exchange of DNA TAXIS ability to move toward or away from certain stimuli NUCLEOID REGION where prokaryotic genome is located as a ring of DNA no membrane ENDOSPORES metabolically inactive remain viable in harsh conditions for centuries TRANDUCTION movement of genes between bacteria by bacteriophages CONJUGATION genetic material is transferred between bacterial cells F FACTOR piece of DNA required to produce sex pili Qgt separate plasmid or in bacterial chromosome Qgt cells containing the F plasmid A DNA donors during conjugation transferrable Qgt in chromosome of cell A donor during conjugation recipient A recombinant bacterium R PLASMIDS carry genes for antibiotic resistance PHOTOAUTOTROPH obtains energy from light amp carbon from CO2 CHEMOAUTOTROPH obtains energy from inorganic chemicals amp carbon from CO2 PHOTOHETEROTROPH obtains energy from light amp carbon from organic compounds CHEMOHETEROTROPH obtains energy from organic compounds amp carbon from organic compounds OBLIGATE AEROBES require 02 for cellular respiration OBLIGATE ANAEROBES poisoned by 02 use fermentation or anaerobic respiration FACULTIVE ANAEROBES can survive with or without 02 NITROGEN FIXATION conversation of atmospheric nitrogen N2 A ammonia NH3 HETEROCYTES nitrogenfixing cells that exchange metabolic products with photosynthetic cells BIOFILMS surface coating colonies where metabolic cooperation occurs in some prokaryotic species EXTREMOPHILES archaea that live in extreme environments Qgt halophiles salt amp thermophiles heat METHANOGENS live in swamps amp marshes produce methane as waste strict anaerobes PROTEOBACTERIA Gram negative include photo amp chemoautotrophs heterotrophs aerobic or anaerobic Qgt gig A usu closely associated with prokaryotic hosts i A eg soil bacterium A converts N2 A NH3 Gamma A eg sulphur bacteria Ecoi Dim A eg slime secreting myxobacteria Epsilon A eg ones that cause blood poisoning amp stomach ulcers 556 BACTERIAL SHAPES M A spherical Biilli A rod Spirilla A spiral CHLAMYDIAS parasites within animal cells SPIROCHETES helical heterotrophs eg ones that cause syphilis amp Lyme disease CYANOBACTERIA photoautotrophs generate O2 CHEMICAL CYCLING chemoautotrophs acts as decomposers nitrogenfixing ones add usable nitrogen SYMBIOSIS relationship between larger host amp smaller symbiont mutualism commensalism parasitism EXOTOXINS cause disease even if producing prokaryote is absent ENDOTOXINS released when bacteria die amp cell walls break down BIOREMEDIATION use of organisms to remove pollutants from the environment Angiosperm Reproduction amp Biotechnology FERTILISATION of gametes A sporophyte dominant generation in angiosperms STAMEN consists of filament topped by an anther A produces pollen CARPEL has style with stigma A pollen lands goes down to ovary amp its ovules COMPLETE amp INCOMPLETE FLOWERS has all 4 organs doesn t have all four organs Qgt clusters of flowers A inflorescences POLLEN GRAINS develop from microspores in pollen sacs A successful pollination anther A stigma A produces pollen tube into ovary to discharge sperm A 2celled male gametophyte amp cell wall MEGASPORES produced by meiosis in ovule A embryo sacs female gametophytes DOUBLE FERTILISATION results from discharge of 2 sperm from pollen tube A embryo sac Qgt one fertilised egg other combines with polar nuclei A 3n endosperm food storing Qgt each ovule A seed ovary A frlrc SEED COAT hard protective coat that protects embryo amp endosperm HYPOCOTYLE RADICLE amp EPICOTYL shoot root amp shoot tip below embryonic axis that terminates in the radicle embryonic root above cotyledons COLEOPTILE amp COLEORHIZA two sheathes that enclose embryo of grass seed A young shoot young shoot IMBIBITION uptake of water due to low water potential of seed A initiates germination FRUIT protects enclosed seed aids in seed dispersal A dry if ovary dries out fleshy is ovary is thick soft amp sweet Qgt Simple A simple or several fused carpels peas Qgt Aggregate A single flower multiple separate carpels raspberry Qgt Multiple A inflorescence pineapple Qgt Accessory A contains other floral parts in addition to ovaries apple FRAGMENTATION separation of parent plant into parts A whole plants asexual reproduction vegetative reproduction APOMIXIS asexual production of seeds from diploid cell DIOECIOUS species that have stamens amp carpels on different plants SELF INCOMPATABILITY plant rejects its own pollen A blocks growth in pollen tube CALLUS mass of dividing undifferentiated cells that forms when stem is cut A adventitious roots STOCK amp SCION provides root system grafted onto stock PROTOPLAST FUSION creating hybrid plants by fusing protoplasts A plant cells with cell walls removed BIOFUELS made by fermentation amp distillation of plant material s eg cellulose Plant Responses to Internal amp External Signals ETIOLATION morphological adaptations for growing in darkness Qgt exposure to light causes de etioation A sprouts amp roots grow normally CELL SIGNAL PROCESSING reception transduction amp response due to a hormone or environmental stimulus Qgt Reception internal amp external signals detected by receptors proteins that change as a reponse to certain stimuli Qgt Transduction second messengers transfer amp amplify signals from receptors Qgt Response signal transduction pathway leads to regulation of one or more cellular activies I usu involve increased activity of enzymes transcriptional or post transcriptiona modification SPECIFIC TRANSCRIPTION FACTORS bind directly to specific regions of DNA control transcription of genes POSITIVE TRANSCRIPTION FACTORS proteins that increase transcription of specific genes Qgt negative transcription factors have the opposite effect POSTTRANSLATIONAL MODIFICATION modification of existing proteins in signal response Qgt usu includes phosphorylation of specific amino acids HORMONES chemical signals that coordinate different parts of an organism TROPSIM any response resulting curvature of organs towards or away from stimulus caused by hormones PHOTOTROPISM plant39s response to light A bend towards light if coleoptile is present Qgt caused by chemical messenger auxin any chemical that promotes elongation of coleoptile AUXIN involved in root formation amp branching affects secondary growth by inducing cell division in vascular cambium amp influencing differential of secondary xylem AUXIN TRANSPORTER PROTEINS move hormone from basal end of one cell A apical end of neighbouring ACID GROWTH HYPOTHESIS auxin stimulates proton pumps in plasma membrane Qgt lower pH of cell wall A activate expansins enzymes that loosen plant39s cell wall CYTOKININS stimulate cytokinesis produced in actively growing tissues eg roots APICAL DOMINANCE terminal bud s ability to suppress development of auxiliary buds Qgt involves interaction of cytokinesis amp auxin GIBBERELLINS have a variety of effects such as stem elongation fruit growth amp seed germination Qgt stimulate cell elongation amp cell division in stems GERMINATION after water is imbibed release of gibberellins from the embryo signals seeds to germinate BRASSINOSTEROIDS chemically similar to the sex hormones of animals A induce cell elongation amp division in stem segments ABSCISIC ACID slows growth A seed dormancy amp drought tolerance ETHYLENE produced in response to stress eg drought injury infection flooding etc Qgt effects include response to mechanical stress senescence leaf abscission fruit ripening Qgt induces triple response A allows growing shoot to avoid obstacles SENESCENCE programmed death of plant cells or organs LEAF ABSCISSION change in balance of auxin amp ethylene A when leaves fall down in autumn PHOTOMORPHOGENESIS effects of light on plant morphology BLUELIGHT PHOTORECEPTORS control hypocotyl elongation stomatal opening amp phototropism PHYTOCH ROM ES pigments that regulate many of the plant39s responses to light Qgt red light amp far red light increased amp inhibited germination shade avoidance CIRCADIAN RHYTHMS cycles that are about 24 hours long governed by internal clock PHOTOPERIODISM physiological response to photoperiod SHORTDAY amp LONGDAY PLANTS light period lt critical length light period gt critical length DAYNEUTRAL PLANTS flowering is controlled by plant maturity not photoperiod FLORIGEN the flowering signal A not yet chemically identified GRAVITROPISM roots show positive against shoots show negative towards STATOLITHS specialised plastids containing dense starch grains A may be used to detect gravity THIGMOMORPHOGENESIS changes in form due to mechanical disturbance Qgt thigmotropism A growth in response to touch ACTION POTENTIALS transmission of electrical impulses due to responses to mechanical stimulation ENVIRONMENTAL STRESSES include drought flooding cold stress etc Qgt Drought I plants reduce transpiration by closing stomata A slows growth reduces exposed surface area I growth of shallow roots A inhibited Qgt Flooding I destruction of root cortex cells A air tubes A survive oxygen deprivation Qgt Salt stress I plants produce solutes tolerated at high concentrations A water potential of cells more negative than soil solution Qgt Heat stress I heat shock proteins protect other proteins from being denatured Qgt Cold stress I plants alter lipid composition of membranes A decreased fluidity due to cold METHYUASMONIC ACID can activate expression of genes involved in plant defenses VIRULENT AND AVIRULENT PATHOGENS plant has little specific defense against may harm but doesn t kill GENEFORGENE RECOGNITION recognition of pathogenderived molecules by protein products of specific plant disease resistance genes R PROTEINS activate plant defenses A signal transduction pathways Qgt include hypersensitive response and systemic acquired resistance HYPERSENSITIVE RESPONSE cell and tissue death near infection site production of phytoalexin and PR proteins A attack pathogen stimulate changes in cell wall to confine pathogen SYSTEMIC ACQUIRED RESISTANCE systemic expression of defense genes longlasting Qgt triggered by salicylic acid A synthesised around infection site Animal Form and Function ANATOMY the biological form of an organism PHYSIOLOGY the biological functions an organism performs INTERSTITIAL FLUID fills space between cells A allows for movement of material into and out of cells EPITHELIAL TISSUE covers outside of body lines organs and cavities within the body A closely joined cells Qgt cuboidal dice columnar sideways bricks or sguamous floor tiles Qgt arrangement may be simple single layer stratified multiple tiers or pseudostratified single layer of varying lengths CONNECTIVE TISSUE binds and supports other tissues A sparsely packed cells scattered throughout extracellular matrix A matrix consists of fibres in liquid jellylike or solid foundation Qgt Collagenous fibres A strength and flexibility Qgt Elastic fibres A stretch and snap back to original length Qgt Reticular fibres A join connective tissue with adjacent tissue made of protein and contains fibroblasts secrete protein of extracellular fibres and macrophages LOOSE CONNECTIVE TISSUE bind epithelia to underlying tissues holds organs in place CARTILAGE strong and flexible support material eg nose FIBROUS CONNECTIVE TISSUE found in tendons attach muscles to bone and ligaments connect bones orjoints ADIPOSE TISSUE BLOOD AND BONE stores fat for insulation and fuel composed of blood cells and cell fragments in blood plasma mineralised and forms skeleton MUSCLE TISSUE consists of muscle fibres long cells A contract in response to nerve signals Qgt Skeletal muscle striated A responsible for voluntary movement Qgt Smooth muscle A responsible for involuntary body activities Qgt Cardiac muscle A responsible for contraction of heart NERVOUS TISSUE senses stimuli and transmits signals throughout the animal Qgt Neurons A transmit nerve impulses Qgt Glial cells lglial A help nourish insulate and replenish neurons NERVE IMPULSES AND HORMONES fastacting temporary slowacting ong asting REGULATOR uses internal control mechanisms to moderate internal change A environmental fluctuation CONFORMER internal condition may vary to certain external changes NEGATIVE FEEDBACK build up of end product shuts system off A fluctuations above or below a set point ACCLIMIATISATION homeostasis can adjust to changes in external environment THERMOREGULATION maintenance of internal temperature within a tolerable range ENDO AND ECTOTHERMIC heat by metabolism heat from external sources INTERGUMENTARY SYSTEM skin hair and nails A heat regulation VASODILATION AND CONSTRICTION increased blood flow and heat loss decreased blood flow and lowering of heat loss through skin COUNTERCURRENT EXCHANGE transfer of heat between fluids flowing in opposite directions BIOENERGETICS overall flow and transformation of energy in an animal A determines how much food relative to size activity and environment BIOSYNTHESIS body growth and repair synthesis of storage material like fat production of gametes METABOLIC RATE amount of energy used in a unit of time Qgt BLa A endotherm at a comfortable temperature Qgt Standard A ectotherm at rest at a specific temperature TORPOR decreased activity and metabolism hibernation and estivation The Immune Svstem IMMUNE SYSTEM recognises foreign bodies A production of immune cells and proteins INNATE IMMUNITY effective from time of birth include nonspecific responses to pathogens consists of external barriers internal cellular and chemical defenses ACQUIRED IMMUNITY develops after exposure very specific receptor diversity lack of reactivity against host cells immunological memory LYSOZYME enzyme that digest microbial cell walls digestive system HEMOCYTES carry out phagocytosis and secrete antimicrobial peptides A disrupt bacterial plasma membranes BARRIER DEFENSES include skin and mucous membranes of respiratory urinary and reproductive tracts Qgt mucus saliva tears low pH of skin etc TOLLLIKE RECEPTORS recognisable receptors on pathogens A body recognises them A white blood cell engulfs A fuses with lysosome PHAGOCYTIC CELLS cells that carry out phagocytosis Qgt Neutrophils A engulf and destroy microbes Qgt Macrophages A part of lymphatic system found throughout body Qgt Eosinophils A discharge destructive enzymes Qgt Dendritic cells A stimulate development of acquired immunity INTERFERON proteins that provide innate defense against viruses help activate macrophages COMPLEMENT SYSTEM made of 30 proteins causes lysis of invading cells helps trigger inflammation INFLAMMATORY RESPONSE injury A mast cells release histamine A increase local blood supply allows more phagocytes and antimicrobial proteins to enter tissues Qgt E accumulates at site of inflammation rich in white blood cells dead microbes and cell debris Qgt either local or systemic throughout body Qgt M A systemic inflammatory response triggered by pyrogens from macrophages and toxins from pathogens SEPTIC SHOCK ife threatening condition caused by overwhelming inflammatory response NATURAL KILLER CELLS attack damaged cells without Class 1 MHC on surface LYMPHOCYTES white blood cells A recognise and respond to antigens Qgt T cells from thymus B cells from bone marrow Qgt contribute to immunological memory CYTOKINES secreted by macrophages and dendritic cells A recruit and activate lymphocytes ANTIBODIES structurally similar to B cell receptors A lack transmembrane regions that anchor receptors to plasma membrane ANTIGENS AND ANTIGEN RECEPTORS foreign molecule to which a lymphocyte responds 100k identical ones on a single B or T cell Qgt recognise the same epitopeantigenic determinants PLASMA CELLS EFFECTOR B CELLS given rise to by B cells A secrete proteins called antibodies and immunoglobins B CELL RECEPTORS bind to specific intact antigens consist of 2 identical heavy chains and light chains Qgt chains form a constant region each chain contains a variable region A amino acid sequence varies extensively between B cells T CELL RECEPTOR consists of 2 different polypeptide chains A tips variable rest constant can bind to free antigens or on surface of a pathogen A bind to antigen fragments presented on host cell MHC MOLECULES cellsurface proteins that antigen fragments are bound to encoded by a family of genes A maior histocompatability complex Qgt transport and bind antigen fragments to cell surface A antigen presentation A nearby T cell can detect them CLASS I AND II MHCs found on almost all nucleated cell of the body and display peptide antigens to cytotoxic T cells located mainly on dendritic cells macrophages and B cells Qgt antigen presenting cells A display antigens to cytotoxic T cells and helper T cells LYMPHOCYTE DIVERSITY differences in variable region A specificity of antigen receptors Qgt immunoglobin lg gene encodes one chain of the B cell receptor I many different chains can be produced from the same lg chain gene by rearrangement of DNA SELFTOLERANCE lymphocytes tested for sef reactivity A apoptosis or rendered non functiona CLONAL SELECTION proliferation of lymphocytes Qgt shortlived effector cells or ong ived memory cells PRIMARY AND SECONDARY IMMUNE RESPONSES first exposure A plasma cells generated T cells activated to effector forms next exposures A memory cells facilitate a faster more efficient response HUMORAL IMMUNE RESPONSE involves activation and clonal selection of B cells A secreted antibodies for extracellular pathogens CELLMEDIATED IMMUNE RESPONSE activation and clonal selection of cytotoxic T cells for intracellular pathogens HELPER T CELLS AND CD4 surface protein binds Class II molecule A T cell joined to antigen presenting cell when activation occurs A secretes cytokines A stimulate other lymphocytes CYTOTOXIC T CELLS effector cells in ce mediated response make 1 A surface protein that enhances interaction between target and cytoxic cells bind to Class I complex on infected cell A active killer A secretes proteins that destroy infected target B CELLS characterises humoral response A secretion of antibodies activation aided by cytokines and antigen binding helper Ts clonal selection A plasma cells effectors of humoral MONO AND POLYCLONAL ANTIBODIES prepared from a single clone of B cells grown in culture products of many different clones of B cells after exposure to microbial antigen NEUTRALISATION AND OPSONISATION pathogen can no longer infect host A bound to an antibody antibodies bound to antigens increase phagocytosis MEMBRANE ATTACK COMPLEX antibodies with proteins of complement systemA generate complex and cell lysis ACTIVE IMMUNITY develops naturally in response to an infection or immunisation PASSIVE IMMUNITY immediate shortterm protection A injection of antibodies mother to fetus etc ALLERG ENS antigens that cause a hypersensitive response AUTOIMMUNE DISEASES immune system loses selftolerance gt turns against certain molecules eg lupus IMMUNODEFICIENCY hereditary or developmental disease gt prevents proper functioning of innate humoral andor cell mediated defenses Qgt Acquired immunodeficiency results from exposure to chemical and biological agents LATENCY inactive state where virus remains in host Term 3 Animal Form Function amp Development Hormones amp the lE1clocrine Svstem HORMONES chemical signals secreted into circulatory system communicate regulatory messages within body reach all parts of body but only target cells can respond Qgt usu polypeptides proteins amp peptides amines derived from amino acids steroid hormones Lipidsoluble steroid A pass easily through cell membranes receptors inside travel in bloodstream bound to transport proteins response is usu a change in gene expression Qgt steroids thyroid hormones amp hormonal form of vitamin D enter target cells A bind to protein receptors in cytoplasm or nucleus A proteinreceptor complexes act a transcription factors in nucleus to regulate transcription of specific genes Watersoluble polypeptides amp amines A can39t pass through membrane receptors outside secreted by exocytosis travel freely in bloodstream Qgt binding of hormone to receptor initiates a signal transduction pathway A responses in cytoplasm enzyme activation or a change in gene expression same hormone can have different effects A different receptors different signal transduction pathway proteins for carrying out response ENDOCRINE SYSTEM secretes hormones A slower but longeracting responses eg reproduction growth energy metabolism NERVOUS SYSTEM conveys high speed electrical signals along neurons that regulate other cells CHEMICAL SIGNALS bind to receptor proteins or target cells A only those cell respond to signal eg hormones local regulators neurotransmitters neurohormones pheromones ENDOCRINE GLANDS ductless glands that secrete hormones directly into surrounding fluid EXOCRINE GLANDS glands with ducts that secrete substances onto body surfaces or into body cavities eg tear ducts LOCAL REGULATORS nonhormonal chemical signals that travel short distances by diffusion help regulate blood pressure nervous system function amp reproduction 2 types A paracrine amp autocrine PARACRINE SIGNALLING acts on cells near secreting cell types of local regulators A cytokines amp growth factors nitric oxide NO prostaglandins Qgt help regulate aggregation of platelets early step in forming blood clots AUTOCRINE SIGNALLING 39 acts on secreting cell itself NEURONS nerve cells contact target cells at synapses NEUROTRANSM39 39ERS secreted by neurons at synapses A diffuse short distances to bind to receptors on the target cell play a role in sensation memory cognition amp movement NEUROHORMONES class of hormones that originate from neurons amp diffuse through bloodstream PHEROMONES chemical signals released from the body A used to communicate with other individuals of the species used to mark food sources warn of predators attract potential mates EPINEPHRINE ADRENALINE 39 hormone involved in response to shortterm stress binds to receptors on plasma membrane of liver cells triggers release of messenger molecules A activate enzymes A release of glucose into bloodstream NEGATIVE FEEDBACK LOOP inhibits response by reducing initial stimulus regulates many hormonal pathways involved in homeostasis ANTAGONISTIC HORMONE PAIRS 2 hormones that cause the opposite effects of each other regulates many hormonal pathways involved in homeostasis ISLETS OF LANGERHANS clusters of endocrine cells in the pancreas alpha cells produce glucagon beta cells produce insulin INSULIN reduces blood glucose levels Qgt promotes cellular uptake of glucose slows glycogen breakdown in liver promotes fat storage GLUCAGON increases blood glucose levels Qgt stimulates conversion of glycogen to glucose in liver stimulates breakdown of fat amp protein into glucose ECDYSONE amp JUVENILE HORMONE in insects only A released by prothoracic glands promotes retention of larval characteristics former promotes molting in presence ofJH development of adult characteristics without JH HYPOTHALAMUS 39 receives information from nervous system A initiates response through endocrine system PITUITARY GLAND attaches to hypothalamus composed of posterior pituitary amp anterior pituitary Qgt stores amp secretes hormones made in hypothalamus Qgt makes amp releases hormones under regulation of hypothalamus OXYTOCIN released form posterior pituitary amp acts directly on nonendocrine tissues induces uterine contractions amp release of milk positive feedback A stimulus leads to even greater response ANTIDIURECTIC HORMONE ADH 39 enhances water reabsorption in kidneys HORMONE CASCADE PATHWAY 39 hormone stimulates release of a series of other hormones last which activates a nonendocrine target cell eg thyroid hormone A involves hypothalamus anterior pituitary thyroid gland usu regulated by negative feedback TROPIC HORMONE regulates function of endocrine cells or glands ie thyroidstimulating hormone TSH adenocorticotropic hormone ACTH folliclestimulating hormone FSH luteinizing hormone LH Qgt control synthesis of sex hormones NONTROPIC HORMONE 39 targets nonendocrine tissues eg prolactin PRL melanocytestimulating hormone MSH Qgt stimulates lactation in mammals with diverse effects in different vertebrates Qgt influences skin pigmentation in some vertebrates amp fat metabolism in mammals GROWTH HORMONE GH secreted by anterior pituitary has tropic amp nontropic actions promotes growth directly has diverse metabolic effects stimulates production of growth factors THYROID GLAND two lobes on ventral surface of trachea produces 2 iodine containing hormones A triiodothyronine T3 amp thyroxine T4 stimulate metabolism amp influence development amp maturation PARATHYROID HORMONE PTH 39 released by parathyroid glands increases level of blood Ca releases Ca from bone stimulates reabsorption of Ca in kidneys indirect effect A stimulates kidneys to activate vitamin D A promotes intestinal uptake of Caquot from blood CALCITONIN 39 released by thyroid gland decreases level of blood Ca stimulates Caquot deposition in bones amp secretion by kidneys ADRENAL GLANDS adjacent to kidneys each gland consists of adrenal cortex outer portion amp adrenal medulla inner portion Qgt produces small amounts of steroid hormone that function as sex hormones Qgt secretes epinephrine amp norepinephrine noradrenaline I members of class of compounds called catecholamines I secreted in response to stressactivated impulses from nervous system I trigger release of glucose amp fatty acids into blood I increase oxygen delivery to body cells I direct blood toward heart brain amp skeletal muscles I direct blood away from skin digestive system amp kidneys CORTICOSTEROIDS released by adrenal cortex in response in stress triggered by hormone cascade pathway via hypothalamus amp anterior pituitary 2 types A glucocorticords amp mineralocarticoids Qgt influence glucose amp metabolism immune system eg cortisol Qgt affect salt amp water balance eg aldosterone ANDROGENS stimulate development amp maintenance of male reproductive system eg testosterone Qgt causes increase in muscle amp bone mass ESTROGENS stimulate development of female secondary sex characteristics amp maintenance of female reproductive system eg estradiol PROGESTINS primarily involves in preparing amp maintaining uterus eg progesterone MELATONIN released by pineal gland in brain controlled by lightdark cycles primary functions related to biological rhythms associated with reproduction Neurons Svngpses amp Signalling NEURONS nerve cells that transfer information within the body use electrical ong distance or chemical shortdistance signals transmission of information depends on the path of neurons along which the signal travels ganglia simple clusters or a M more complex organisation process information most of a neuron s organelles are in the cell body most have dendrites A highly branched extensions that receive signals from other neurons have an E A usu much longer extension that transmits signals to other cells at synapses Qgt joins cell body at axon hillock synapse A junction between axon amp another cell synaptic terminal of an axon passes information across the synapse using neurotransmitters chemical messengers information transmitted from a presynaptic cell neuron A postsynaptic cell neuron muscle or gland cell glia nourish amp insulate most neurons contain gated ion channels that open or close in response to stimuli can produce hundreds of action potentials per second SENSORY NEURONS transmit information from sensors that detect external stimuli amp internal conditions INTERNEURONS integrate information in ganglia or brain MOTOR NEURONS carry motor output from ganglia or brain A muscle or gland activity CENTRAL NERVOUS SYSTEM CNS where integration takes places includes brain amp nerve cord PERIPHERAL NERVOUS SYSTEM PNS brings information to amp from CNS MEMBRANE POTENTIAL voltage difference in electrical charge across a ce s plasma membrane messages are transmitted as changes in membrane potential changes in response to opening amp closing of gated ion channels RESTING POTENTIAL membrane potential of a neuron not sending signals Kquot greater inside cell Naquot greater outside of cell sodium potassium pumps use ATP to maintain these gradients across the plasma membrane Qgt concentration gradients A chemical potential energy I opening of ion channels converts chemical potential A electrical neuron at this state has many open Kquot channels few open Na channels A Kquot diffuses out anions trapped inside cell contribute to negative charge in neuron at equilibrium A both electrical amp chemical gradients are balanced EQUILIBRIUM POTENTIAL membrane voltage for a particular ion at equilibrium Qgt Kquot A negative Na A positive HYPERPOLARISATION gated Kquot channels open A Kquot diffuses out A inside of cell becomes more negative increase in magnitude of membrane potential DEPOLARISATION gated Na channels open A Na diffuses into cell reduction in magnitude of membrane potential GRADED POTENTIALS changes in polarisation where magnitude of charge varies with the strength of the stimulus VOLTAGEGATED CHANNELS Na amp Kquot channels that respond to a change in membrane potential stimulus depolarises membrane A Na diffuse in via open channels movement of Na in A increases depolarisation A more Na channels open like pos feedback ACTION POTENTIALS massive change in membrane voltage as a result of a strong stimulus occurs if stimulus causes membrane voltage to cross a particular threshold allornone depolarisation of a neuron s plasma membrane signals that carry information along axons frequency of action potentials can reflect the strength of a stimulus can travel long distances by regenerating itself along the axon at site where action potential is generated usu axon hillock an electrical current depolarises the neighbouring region of the axon membrane only travel towards synaptic terminals Qgt inactivated Na channels behind zone of depolarisation prevent it from traveling backwards speed increases with axon s diameter formed only at nodes of Ranvier A gaps in myelin sheath where voltagegated Na channels are found jump between nodes in myelinated axons A saltatory conduction causes the release of the neurotransmitter inside synaptic vesicles ACTION POTENTIAL STAGES 1 Resting Potential Most voltagegated Na amp Kquot channels are closed but some K channels not voltagegated are open 2 Depolarisation Voltagegated Na channels open A Na diffuses into cell 3 Rising Phase Threshold is crossed amp membrane potential increases 4 Action potential is reached 5 Falling Phase Voltagegated Na channels become inactivated voltagegated Kquot channels open amp Kquot flows out of the cell 6 Undershoot Membrane permeability to Kquot is initially higher A voltagegated Kquot channels close A resting potential is restored REFRACTORY PERIOD occurs after an action potential A second action potential cannot be initiated temporarily result of temporary inactivation of Na channels MYELIN SHEATH insulate axons in vertebrates A action potentia s speed increases Qgt made by glia A oligodendrocytes in CNS amp Schwann cells in PNS SYNAPSE junction between neuron amp another cell Qgt Electrical synapse A electrical current flows from one neuron to another Qgt Chemical synapse A chemical neurotransmitter carries information across gap most synapses presynaptic neuron synthesises amp packages the neurotransmitter in synaptic vesicles located in the synaptic terminal A activated by action potential neurotransmitter diffuses across the synaptic cleft A received by postsynaptic cell DIRECT SYNAPTIC TRANSMISSION involves binding neurotransmitter to ligandgated ion channels in postsynaptic cell Qgt release of neurotransmitter A diffuses out of synaptic cleft taken up by surrounding cells degraded by enzymes POSTSYNAPTIC POTENTIAL generated when neurotransmitter binding causes ion channels to open graded amp do not regenerate Qgt Excitatory postsynaptic potential EPSPs A depolarisations that bring membrane potential towards threshold I single EPSP too small to trigger action potential in a postsynaptic neuron I Temporal summation A 2 EPSPs produced in rapid succession A possible action potential I Spatial summation A EPSPs produced nearly simultaneously by different synapses on the same postsynaptic neuron add together A possible action potential Qgt Inhibitory postsynaptic potential PSPs A hyperpolarisations that move membrane potential farther away from threshold I IPSP summation A can counter the effect of an EPSP summed effect determines whether axon hillock reaches threshold amp generates action potential INDIRECT SYNAPTIC TRANSMISSION neurotransmitter binds to a receptor that39s not part of an ion channel activates signal transduction pathway involving a second messenger in postsynaptic cell effects A slower onset but last longer NEUROTRANSMI39I I39ER type of chemical messenger associated with neurons same one can have different effects on different types of cells five major classes Qgt Acetylcholine I common in vertebrates amp invertebrates excitatory transmitter in vertebrates Qgt Biogenic amines I eg dopamine serotonin epinephrine norepinephrine active in CNS amp PNS Qgt Amino acids I eg gamma aminobutyric acid GABA amp glutamate in CNS Qgt Neuropeptides I eg substance P amp endorphins relatively short chains of amino acids Qgt Gases I eg nitric acid carbon monoxide local regulators in PNS affect perception of pain Developmental Fate of Cells DIFFERENTIATION expression of different genes A different cell types Qgt during early cleavage divisions embryonic cells must become different Qgt after cell asymmetries are set up interactions among embryonic cells influence their fate A usu changes in gene expression induction I mediated by diffusible chemicals or cellcell interactions FATE MAPS general territorial diagrams of embryonic development AXES OF THE BASIC BODY PLAN nonamniotic vertebrates A set down early during oogenesis fertilisation amniotes A local environmental differences play a major role in establishing initial differences between cell amp body axes TOTIPOTENT can develop into all cell types usu only zygote embryonic development proceeds A potency becomes more limited CYTOPLASMIC DETERMINANTS egg s cytoplasm is heterogeneous A dividing cells vary in the cytoplasmic determinants they contain unevenly distributed in egg A establish body axes PATTERN FORMATION arrangement of organs amp tissues in their characteristic places in 3D space development of spatial organisation inductive signals play a major role POSITIONAL INFORMATION molecular cues that control pattern formations tells a cell where it is with respect to body axes determines how the cell amp its descendants respond to future molecular signals LIMB BUDS bumps of tissue that become vertebrate limb embryonic cells in them respond to positional information indicating location along 3 axes A proximaldistal anterior posterior dorsa ventra organiser regions A apical ectodermal ridge AER zone of polarising activity ZPA Qgt thickened ectoderm at bud s tip mesodermal tissue under ectoderm where posterior side of bud is attached to the body produces an inductive signal that conveys positional information of quotposterior SIGNAL MOLECULES produced by inducing cells influence gene expression in cells receiving them lead to differentiation amp development of particular structures HOX GENES play a role in limb pattern formation Ecology Ecologv amp the I3iosphere ECOLOGY scientific study of interactions between organisms amp the environment determine distribution of organisms amp their abundance ORGANISMAL ECOLOGY studies how an organism39s structure physiology amp behaviour meet environmental challenges POPULATION group of individuals of the same species living in an area POPULATION ECOLOGY factors affecting how many individuals of a species live in an area COMMUNITY group of populations of different species in an area COMMUNITY ECOLOGY interacting species in a community ECOSYSTEM community of organisms in an area amp the physical factors with which they interact ECOSYSTEM ECOLOGY energy flow amp chemical cycling gt various biotic amp abiotic components LANDSCAPE mosaic of connected ecosystems LANDSCAPE ECOLOGY deals with arrays of ecosystems amp how they39re arranged in a geographic region BIOSPHERE global ecosystem GLOBAL ECOLOGY influence of energy amp materials on organisms across the biosphere DISPERSAL movement of individuals away from centres of high population density or from their area of origin SPECIES TRANSPLANTS includes organisms intentionally or accidentally relocated from their original distribution gt can disrupt ecosystems POTENTIAL RANGE all possible area that an organism can occupy some species limited by habitat selection behaviour factors include interactions with other species predation competition wind rocks soil CLIMATE temperature sunlight water wind ong term prevailing weather conditions of an area Qgt Macroclimate A global regional or local level Qgt Microclimate A very fine patterns eg organisms under a log AIR TEMPERATURE amp BODIES OF WATER warm air overland rises air cools at higher elevation cooler air sinks over water cool air over water moves inland replacing rising warm air overland EFFECTS OF MOUNTAINS amount of sunlight reaching an area local temperature rainfall rising air releases moisture on windward side A quotrain shadow as it absorbs moisture on the leeward side BIOM ES major ecological associations that occupy broad geographic regions land amp water nature determined by varying combinations of biotic amp abiotic factors in terms of area mostly aquatic A stratified into zones by light penetration temperature amp depth PHOTIC ZONE of lakes amp oceans highest aquatic zone sufficient light for photosynthesis APHOTIC ZONE of lakes amp oceans receives little light BENTHIC ZONE of lakes amp oceans organic amp inorganic sediment at the bottom of all aquatic zones Qgt communities of organisms here A benthos DETRITUS dead organic matter that falls from productive surface water A food ABYSSAL ZONE of ocean most extensive part of ocean A 2000 6000m organisms have adapted to continuous cold amp extremely high water pressure INTERTIDAL ZONE of ocean periodically submerged amp exposed by the tides variation in temperature amp salinity mechanical forces of wave action MARINE BETHIC ZONE of oceans seafloor below the surface water of the neritic coastal amp offshore pelagic zone OCEAN PELAGIC ZONE 70 of Earth39s surface phytoplankton zooplankton free swimming animals THERMOCLINE temperature boundary separating warm upper layer amp cold deeper water oceans amp most lakes TU RNOVER semi annua mixing of waters in lakes during spring amp autumn mixes oxygenated water from surface amp nutrientrich water from the bottom OLIGOTROPHIC LAKES nutrientpoor oxygenrich A fish EUTROPHIC LAKES nutrientrich often depleted of oxygen A plants LITTORAL ZONE of lakes shallow amp we ighted A rooted amp floating aquatic plants LIMNETIC ZONE of lakes too deep for rooted aquatic plants A zooplankton amp phytoplankton WETLAND habitat inundated by water at least some of the time supports plants adapted to water saturated soil can develop in shallow basins along flooded river banks coasts of large lakes amp seas among most productive biomes home to diverse invertebrates amp birds ESTUARY transition area between river amp sea salinity varies with rise amp fall of tides nutrientrich highly productive A marine invertebrates amp fish CORAL REEFS calcium carbonate skeletons of coral corals require a solid substrate for attachment DEEPSEA HYDROTHERMAL VENTS of volcanic origin on mid oceanic ridges autotrophs A chemoautotrophic prokaryotes DISTURBANCE modify biome patterns eg storms fire human activity CLIMOGRAPH plot of temperature amp precipitation in a reigon ECOTONE area of intergradation between 2 terrestrial biomes VERTICAL LAYERING may consist of an upper canopy ow tree layer shrub understory ground layer of herbaceous plants forest floor amp root layer provides diverse habitats for animals TROPICAL RAINFORESTS amp DRY FORESTS vertically layered intense competition for light rainfall is relatively constant precipitation is highly seasonal DESERT precipitation is low amp highly variable 30 gt cm per year may be either hot or cold SAVAN NA precipitation amp temperature are seasonal grasses amp forbs make up most of ground cover CHAPPARAL highly seasonal gt cool amp rainy winters hot amp dry summers dominated by shrubs small trees grass amp herbs TEMPERATE GRASSLANDS cold dry winters amp hot wet summers plants adapted to droughts amp fire NORTHERN CONIFEROUS FOREST largest terrestrial biome cold amp long winters summers may be hot TEMPERATE BROADLEAF FOREST cool winters amp hot humid summers significant precipitation has vertical layers TUNDRA long cold winters amp cool summers varied precipitation Qgt has permafrost gt permanently frozen layer of soil that prevent water infiltration vegetation is herbaceous eg mosses grasses lichen etc Animal Behaviour BEHAVIOUR nervous system39s response to a stimulus gt carried out by muscular or hormonal system based on physiological systems amp processes helps animal obtain food maintain homeostasis etc subject to natural selection ETHOLOGY scientific study of animal behaviour esp in natural environments 4 behavioural questions What stimulus elicits the behaviour amp what physiological mechanisms mediate the response How does the animal39s experience during growth amp development influence the response mechanisms How does the behaviour aid in survival amp reproduction What39s the behaviour s evolutionary history 56 56 PROXIMATE CAUSATION quothow explanations focus on environmental stimuli that trigger a behaviour amp genetic physiological amp anatomical mechanisms underlying a behaviour ULTIMATE CAUSATION quotwhy explanations focus on evolutionary significance of a behaviour BEHAVIOURAL ECOLOGY study of the ecological amp evolutionary basis for animal behaviour integrates both proximate amp ultimate explanations FIXED ACTION PATTERN sequence of unlearned innate unchangeable behaviours once initiated usu carried to completion triggered by an external cue gt sign stimulus KINESIS simple change in activity or turning rate in response to a stimulus eg sow bugs are more active in dry areas less active in humid TAXIS automatic oriented movement toward or away from a stimulus eg fish swimming upstream MIGRATION regular longdistance change in location animals orient themselves using the sun amp their circadian clock the North Star Earth39s magnetic field CIRCANNUAL RHYTHM circadian rhythm in relation to the changing seasons eg migration reproduction SIGNAL behaviour that causes a change in another animal39s behaviour COMMUNICATION transmission amp reception of signals PHEREMONES chemical substances emitted gt communication through odours effective at very low concentrations INNATE BEHAVIOUR developmentally fixed under strong genetic influence LEARNING modification of behaviour based on specific experiences HABITUATION simple form of learning that involves loss of responsiveness to stimuli that convey little or no information eg how car alarms go off amp no one responds IMPRINTING behaviour that includes learning amp innate components usu irreversible distinguished from other learning by a sensitive period Qgt limited developmental phase only time when certain behaviours can be learned SPATIAL LEARNING more complex modification of behaviour based on experience with spatial structure of environment use of landmarks COGNITIVE MAP internal representation of spatial relationships between objects in an animal39s surroundings eg food cache halfway between 2 landmarks ASSOCIATIVE LEARNING animals associate one feature of the environment with another Qgt classical amp operant conditioning COGNITION process of knowing that may include awareness reasoning recollection amp judgement PROBLEM SOLVING process of devising a strategy to overcome an obstacle may be partially learned through observation CROSSFOSTERING STUDY young from one species in care of adults of another species TWIN STUDIES in humans used to compare relative influences of genetics amp environment on behaviour GENES amp BEHAVIOUR a master regulatory gene can control many behaviours multiple genes can contribute to a single behaviour differences at a single locus can sometimes have a large effect on behaviour FORAGING food obtaining behaviour includes recognising searching for capturing amp eating food items OPTIMAL FORAGING MODEL foraging behaviour is a compromise between the benefits of nutrition amp costs of obtaining food natural selection should favour behaviour that minimises costs amp maximises benefits MATING BEHAVIOUR includes seeking or attracting mates choosing among potential mates competing for mates results from a type of natural selection called sexual selection PROMISCUOUS no strong pair bonds or lasting relationships MONOGAMOUS one male mates with one female with similar external morphologies POLYGAMOUS individual of one sex mates with several individuals of the other Qgt Polygyny A one male many females Qgt Polyandry A one female many males rare INTERSEXUAL SELECTION members of one sex choose mates on the basis of certain traits INTRASEXUAL SELECTION involves competition between members of the same sex for mates AGONISTIC BEHAVIOUR often ritualised contest that determines which competitor gains access to a resource GAME THEORY evaluates alternative strategies where the outcome depends on each individual s strategy amp the strategy of other individuals eg side botched lizard A blue orange or yellow throat ALTRIUSM behaviour that reduces individual fitness but increases the fitness of others eg nonreproductive naked mole rats sacrificing themselves for their reproductive king amp queen 3 variables A benefit to recipient cost to altruist coefficient of relatedness average fraction of genes shared INCLUSIVE FITNESS total effect an individual has on proliferating its genes by producing its offspring amp helping close relatives produce offspring KIN SELECTION natural selection that favours altruistic behaviour by enhancing reproductive success of relatives RECIPORCAL ALTRIUSM altruistic behaviour towards unrelated individuals can be adaptive if aided individual returns the favour only works if individuals meet repeatedly amp cheaters are punished explains altruism in humans SOCIAL LEARNING learning through observation of others amp forms the roots of culture CULTURE system of information transfer through observation or teaching that influences behaviour of individuals in a population can alter behaviour amp influence the fitness of individuals MATECHOICE COPYING individuals in a population copy the mate choice of others SOCIOBIOLOGY behaviour results from interactions between genes amp the environment study of social learning amp cultural transmission Population Ecology POPULATION ECOLOGY study of populations in relation to environment includes environmental influence on density amp distribution age structure amp population size POPULATION a group of individuals of a single species living the same general area DENSITY number of individuals per unit area of volume estimated with extrapolation from small samples index of population size markrecapture method DISPERSION pattern of spacing among individuals within the boundaries of a population Qgt clumped uniform random IMMIGRATION influx of new individuals from other areas EMIGRATION movement of individuals out of a population DEMOGRAPHY study of vital statistics of a population amp how they change over time LIFE TABLE agespecific summary of the survival pattern of a population Qgt best made following fate of a cohort A group of individuals of same age SURVIVORSHIP CURVE graphic representation of life table data 3 types in terms of death rate gt low gt high Qgt constant Qgt high A low REPRODUCTIVE TABLE FERTILITY SCHEDULE agespecific summary of reproductive rates in a population LIFE HISTORY of an organism the traits that affect its schedule of reproduction amp survival Qgt age at which reproduction beings Qgt how many offspring amp how often SEMELPARITY BIG BANG REPRODUCTION reproduce once amp die best in unpredictable environments ITEROPARITY REPEATED REPRODUCTION reproduce repeatedly best in dependable environments ZERO POPULATION GROWTH birth rate death rate either low or high for both EXPONENTIAL POPULATION GROWTH population increases under idealised conditions rate of reproduction at its maximum A intrinsic rate of increase Jshaped curve on a graph CARRYING CAPACITY K maximum population size the environment can support LOGISITIC POPULATION GROWTH per capita rate of increase declines as carrying capacity is reached sigmoid S shaped curve on a graph some populations overshoot K before settling down A stable not realistic but useful for estimating ALLEE EFFECT individuals have a more difficult time surviving or reproducing if the population size is too small DENSITYDEPENDENT SELECTION K SELECTION selects for life history traits sensitive to population density DENSITYINDEPENDENT SELECTION r SELECTION selects for life history traits that maximise reproduction DENSITYDEPENDENT POPULATION birth rates fall amp death rates rise with population density form of negative feedback DENSITYINDEPENDENT POPULATION birth amp death rates don t change with population density POPULATION DYNAMICS focuses on the complex interactions between biotic amp abiotic factors that cause variation in population size METAPOPULATIONS groups of populations linked by immigration amp emigration high immigration high survival rate greater stability DEMOGRAPHIC TRANSITION moving from high birth amp death rates A low associated with better health care education etc AGE STRUCTURE relative number of individuals at each age can predict population39s growth trends ECOLOGICAL FOOTPRINT amount of land amp water area needed to sustain the people of a nation measures how close we are to the carrying capacity of Earth Community Ecology COMMUNITY assemblage of populations of various species A potential interaction INTERSPECIFIC INTERACTIONS relationships between species in a community eg competition predation mutualism etc INTERSPECIFIC COMPETITION interaction occurs when species compete for a resource in short supply can lead to competitive exclusion A local elimination of a competing species ECOLOGICAL NICHE total of a species use of biotic amp abiotic resources organism39s ecological role RESOURCE PARTITIONING differentiation of ecological niches eg similar species but one on ground amp one in tree fundamental niche may differ from realised niche CHARACTER DISPLACEMENT tendency for characteristics to be more divergent in sympatric same area populations of 2 species than in allopatric different areas populations of the same 2 species PREDATION interaction one species eats the other CRYPTIC COLOURATION camouflage makes prey difficult to spot Qgt Aposematic colouration A bright warning colouration as a sign of effective chemical defense Qgt Batesian mimicry A palatable or harmless species mimics a harmful model Qgt Mijllerian mimicry A 2 unpalatable species resemble each other HERBIVORY interaction herbivore eats parts of a plant or alga SYMBIOSIS relationship where 2 species live in direct amp intimate contact with each other PARASITISM interaction parasite derives nourishment from a host which is harmed in the process endoparasites live inside host ectoparasites live on the external surface MUTUALISM interaction both species benefit Qgt Obligate A one species cannot survive without the other Qgt Facultative A both species can survive alone COMMENSALISM 0 interaction one species benefits the other is apparently unaffected eg oxen amp bird species A receives protection from oxen SPECIES DIVERSITY variety of organisms that make up a community Qgt Species richness A total number of different species Qgt Relative abundance A proportion of each species out of the total number of individuals TROPHIC STRUCTURE feeding relationships between organisms in a community FOOD CHAINS link trophic levels from producers to top carnivores FOOD WEB branching food chain with complex trophic interactions ENERGETIC HYPOTHESIS suggests that length of a food chain is limited by inefficient energy transfer most data supports this theory DYNAMIC STABILITY HYPOTH ESIS proposes that long food chains are less stable than shorter ones DOMINANT SPECIES most abundant or have highest biomass gt total mass of all individuals in a population exert control over occurrence amp distribution of other species most competitive in exploiting resources andor most successful at avoiding predators INVASIVE SPECIES introduced to new environment often lack predators or disease KEYSTONE SPECIES exert strong control on community by their niche not necessarily abundant FOUNDATION SPECIES cause physical changes in the environment amp affect community structure Qgt can acts as facilitators gt positive effects on survival amp reproduction of some other species in the community eg beavers BOTTOMUP MODEL proposes unidirectional influence from lower to higher trophic levels presence or absence of mineral nutrients determines structure TOP DOWN MODEL TROPHIC CASCADE MODEL control comes from trophic level above predators control herbivores which control primary producers BIOMANIPULATION deliberate alteration to help restore polluted communities NONEQUILIBRIUM MODEL describes communities as constantly changing after being buffeted by disturbances Qgt event that changes community removes organisms from it amp alters resource availability INTERMEDIATE DISTURBANCE HYPOTHESIS suggests that moderate levels of disturbance can foster greater diversity compared to high or low levels Qgt High A excludes sow growing species Qgt Low A dominant species may exclude less competitive species ECOLOGICAL SUCCESSION sequence of community amp ecosystem changes after a disturbance Qgt Primary no soil or secondary soil remains EVAPOTRANSPIRATION evaporation of water from soil transpiration of water from plants SPECIESAREA CURVE quantifies idea that all factors being equal large geographic area more speicies PATHOGENS disease causing microorganisms viruses viroids amp prions Qgt can alter community structure quickly amp extensively ZOONOTIC transfer of pathogens from one species to another through a vector eg avian flu H1N1 Ecosystems ECOSYSTEM consists of all the organisms living in a community abiotic factors LAWS OF THERMODYNAMICS energy can39t be created or destroyed only transformed every exchange of energy increases the entropy of the universe LAW OF CONVERSATION OF MASS matter can39t be created or destroyed TROPHIC LEVELS primary producers A primary consumers A secondary consumers A tertiary consumers DETRIVORES decomposers derive energy from detritus nonliving organic matter PRIMARY PRODUCTION amount of light energy converted to chemical energy by autotrophs during a given time period GROSS PRIMARY PRODUCTION GPP total primary production of an ecosystem NET PRIMARY PRODUCTION NPP GPP energy used by primary producers only type of primary production available to consumers STANDING CROP total biomass of photosynthetic autotrophs at a given time LIMITING NUTRIENT element that must be added for production to increase in an area eg nitrogen amp phosphorus in marine production EUTROPHICATION large amounts of nutrients added to a lake A plants grow fish die ACTUAL EVAPOTRANSPIRATION water annually transpired by plants amp evaporation from a landscape related to net primary production SECONDARY PRODUCTION amount of chemical energy in food converted to new biomass during a given period of time PRODUCTION EFFICIENCY fraction of energy stored in food not used for cellular respiration TROPHIC EFFICIENCY percentage of production transferred from one trophic level to the next 520 multiplied over length of food chain BIOMASS PYRAMID each tier represents dry weight of all organisms at one trophic level inverted in certain aquatic ecosystem A zooplankton gt phytoplankton TU RNOVER TIME ratio o fstanding crop biomass to production GREEN WORLD HYPOTHESIS proposes that several factors keep herbivores in check Qgt plant defenses limited availability of essential nutrients abiotic factors intraspecific competition interspecific interactions BIOG EOCHEMICAL CYCLES nutrient circuits in ecosystems that involve biotic amp abiotic components Qgt water carbon nitrogen phosphorus nutrients in gaseous form A globally less mobile eg calcium A locally factors A importance forms major reservoirs key processes WATER CYCLE moves through evaporation transpiration condensation precipitation movement through surface amp ground water CARBON CYCLE reservoirs include fossil fuels soil sediments solutes in ocean CO2 taken up amp released through photosynthesis TERRESTRIAL NITROGEN CYCLE nitrogen A amino acids proteins nucleic acids N2 A NH4 or NO339 ammonification amp nitrification NO339 A N2 denitrification PHOSPHORUS CYCLE makes up nucleic acids phospholipids ATP most important inorganic form A phosphate PO4339 reservoirs A sedimentary rocks of marine origin oceans phosphate binds with soil particles movement often localised CRITICAL LOAD amount of a nutrient that plants can absorb without damaging ecosystem excess nutrients added from outside cycles A exceeded BIOLOGICAL MAGNIFICATION concentrates toxins at higher trophic levels where biomass is lower Conservation Biology amp Restoration Ecology CONVERSATION BIOLOGY seeks to preserve life amp integrates ecology physiology genetics molecular biology evolutionary biology RESTORATION ECOLOGY applies ecological principles to return degraded ecosystem to conditions as similar as possible to their natural state GENETIC DIVERSITY genetic variation within amp between populations SPECIES DIVERSITY variety of species in an ecosystem or throughout the biosphere ENDANGERED SPECIES in danger of extinction throughout all or a significant portion of its range Qgt 12 of birds 20 of mammals 32 of amphibians THREATENED SPECIES likely to become endangered in the foreseeable future BIOPHILIA recognising the value of biodiversity for its own sake ECOSYSTEM SERVICES all processes through which natural ecosystems amp species help sustain human life eg purification of air amp water detoxification amp decomposition of wastes cycling of nutrients moderating weather extremes INTRODUCED SPECIES moved from native locations to new geographic regions no native predators parasites or pathogens A may spread rapidly gain foothold in new habitat A disrupt adopted community OVEREXPLOITATION human harvesting of wild plants or animals at rates exceeding the ability of populations of these species to rebound SMALLPOPULATION APPROACH studies processes that make small populations extinct prone to positive feedback loops A extinction vortex Qgt small population A loss of genetic diversity A reduction in fitness A smaller population MINIMUM VIABLE POPULATION MVP minimum size needed for a species to survive EFFECTIVE POPULATION SIZE based on a population39s breeding potential DECLININGPOPULATION APPROACH focuses on threatened amp endangered populations that show a downward trend regardless of population size emphasises the environmental factors that caused the decline confirm that population is in decline A study species natural history A develop hypotheses for all possible causes of decline A test hypotheses A apply results for recovery MOVEMENT CORRIDOR narrow strip of quality habitat connecting otherwise isolated patches promoted dispersal amp help sustain populations areas of heavy human use A artificial corridors BIODIVERSITY HOT SPOT relatively small area with a great concentration of endemic species amp many endangered amp threatened species ZONED RESERVE recognises that conservation involves working in mostly human dominated landscapes includes relatively undisturbed area amp modified areas around them A buffer zone established as quotconservation areas BIOREMEDIATION use of living organisms to detoxify ecosystems BIOLOGICAL AUGMENTATION use of organisms to add essential materials to a degraded ecosystem eg nitrogenfixing plants gt increase available nitrogen in soil SUSTAINABLE DEVELOPMENT meets needs of people today without limiting the ability of future generation to meet their needs


Buy Material

Are you sure you want to buy this material for

75 Karma

Buy Material

BOOM! Enjoy Your Free Notes!

We've added these Notes to your profile, click here to view them now.


You're already Subscribed!

Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'

Why people love StudySoup

Jim McGreen Ohio University

"Knowing I can count on the Elite Notetaker in my class allows me to focus on what the professor is saying instead of just scribbling notes the whole time and falling behind."

Amaris Trozzo George Washington University

"I made $350 in just two days after posting my first study guide."

Bentley McCaw University of Florida

"I was shooting for a perfect 4.0 GPA this semester. Having StudySoup as a study aid was critical to helping me achieve my goal...and I nailed it!"


"Their 'Elite Notetakers' are making over $1,200/month in sales by creating high quality content that helps their classmates in a time of need."

Become an Elite Notetaker and start selling your notes online!

Refund Policy


All subscriptions to StudySoup are paid in full at the time of subscribing. To change your credit card information or to cancel your subscription, go to "Edit Settings". All credit card information will be available there. If you should decide to cancel your subscription, it will continue to be valid until the next payment period, as all payments for the current period were made in advance. For special circumstances, please email


StudySoup has more than 1 million course-specific study resources to help students study smarter. If you’re having trouble finding what you’re looking for, our customer support team can help you find what you need! Feel free to contact them here:

Recurring Subscriptions: If you have canceled your recurring subscription on the day of renewal and have not downloaded any documents, you may request a refund by submitting an email to

Satisfaction Guarantee: If you’re not satisfied with your subscription, you can contact us for further help. Contact must be made within 3 business days of your subscription purchase and your refund request will be subject for review.

Please Note: Refunds can never be provided more than 30 days after the initial purchase date regardless of your activity on the site.