Final Study Guide Biology 190
Final Study Guide Biology 190 Bio 190
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Date Created: 04/19/16
Final Exam Study Guide Unit 1 DNA 1. 3.143.15 Nucleotide Structure & Nucleic acids Nucleotide structure monomers of nucleic acids; every nucleotide consists of 3 parts: 5 carbon sugar, negatively charged phosphate group, nitrogenous base; Nucleic acid includes DNA and RNA; polymer consisting of many nucleotide monomers; two strands held together by hydrogen bonds 2. 10.110.16 Hershey & Chase, DNA, RNA, DNA Replication, Central Dogma, Transcription, Translation, mRNA processing, & Mutations. Hershey and Chase: Determined that DNA was hereditary material; bacteriophage virus that infects bacteria only made of DNA and protein; phage attaches to bacterial cell and phage injects DNA into bacterium and protein stays outside (label, centrifuge, blend, centrifuge) liquid (protein) vs pellet (DNA and cell contents); DNA is passed from parent to oofspring through DNA replication 2 experiments bacteriophage (only DNA and protein) and labeled protein infect bacteria blend and centrifuge— protein was only in liquid around pellet which means it did not enter the cell bacteriophage and labeled DNA infect bacteria blend and centrifuge DNA was in the pellet which means it entered the cell—it is the genetic material DNA double stranded helical nucleic acid molecule consisting of nucleotide monomers with deoxyribose sugar and nitrogenous bases A, T, C, G; provides directions for its own replication; sugar phosphate backbone; 5’ end is phosphate on carbon 5 and 3’ is attached to OH group on carbon 3 RNA used for protein synthesis; U instead of T; Ribose sugar; much different place than DNA; singlestranded; ribose has an extra oxygen and is very reactive and less stable than DNA DNA replication: 1 parental molecule yields 2 identical daughter DNA molecules (semiconservative); strands assembled from freefloating nucleotides and added using enzymes; DNA helicase untwists DNA and makes bubbles; DNA polymerase catalyzes nucleotide formation of daughter strand and proofreads; DNA ligase connects growing strand: leading strand is continuous and lagging is not because DNA is antiparallel Central Dogma: DNA is transcribed into RNA moves to nucleus RNA is translated into proteins Transcription: synthesis on RNA under the direction of DNA; DNA to mRNA; in nucleus; DNA gets untwisted and separated but only one strand is transcribed (template strand); hydrogen bonds form between template strand and mRNA; Initiation binds to promoter sequence of RNA and begins synthesis; Elongation RNA strand peels away and nucleotides are added to RNA; Termination everything separates (DNA,RNA, RNA polymerase); promoter DNA’ mature when has small G cap and polyA tail and introns out and exons spliced together Translation: the synthesis of protein under the direction of RNA; mRNA to protein; ribosomes are where it takes place; codons (start AUG and stop UGA) and each specifies for a protein; tRNA tRNA is interpreter that helps anticodons match with codons; ribosome have both small and large subunits and they bring mRNA and tRNA close so they can bond Initiation start codon attaches to small unit and the large subunit adds; Elongationcodon recognition between codon and anticodon, peptide bond formation, translocation P site tRNA leaves ribosome and ribosome translocates tRNA in A site to P site; termination stop codons release factor binds to stop codon signaling the end mRNA processing Poly A tail, small G cap, introns out, exons splicing Mutations permanent change in base sequence of DNA within a gene Nucleotide base substitutions only one letter change Silent mutation: No consequences Missense Mutation: affects amino acid Nonsense: affects amino acid by making it a stop codon always bad Frameshift mutation insertion or deletion shifts reading frame Cam be silent, missense, or nonsense 3. 11.1 Lac operon Promoter, operator, 3 lactose genes, repressor. When lactose is absent in env repressor binds to operator and lactose does not get made When lactose is there inactive repressor and RNA polymerase binds to promoter and makes enzymes that help Unit 2 Cell Structure 1. Review basic chemistry from chapter 2 mainly bonds, polar vs. nonpolar, pH, molecules & atoms Molecule held together by covalent bonds; Covalent bonds the strongest, two atoms chare one or more pairs of electrons Nonpolar vs Polar Nonpolar: atoms exert an equal pull on the electrons, the electrons are shared equally (hydrophobic) Polar: Unequal sharing of electrons; negatively charged electrons get pulled closer to the more electronegative atom an it makes that atom partially negative and the other atom partially positive (pretty much anything with an oxygen) (hydrophilic) 2. 3.13.3 Carbon & making and breaking polymers Carbon 4 electrons in outer ring and so it can form 4 covalent bonds; a hydrocarbon Making and Breaking all polymers Dehydration synthesis: links monomers and water gets released Hydrolysis: breaks bonds and consumes water 3. 3.113.13 Proteins Proteins Made of amino acids R groups determine what amino acid it is Polar R groups either bc its charged or because of an OH group Enzymes are proteins chemical catalysts 4. 3.43.9 Carbohydrates & lipids Carbs Glucose and Fructose are sugar monomers or monosaccharides Maltose G+G; Sucrose G+F, hydrophilic or soluble in water Polysaccharide (all made of glucose): Starch storage in plants; unbranched; Amylase breaks it down Glycogenstorage in animals; branched in liver and muscles Cellulose structural in plants for their wall; cellulose breaks it down; we don’t have but cows and termites have bacteria that break it down; highly branched and bonds switch off top to bottom Lipid no monomer, hydrophobic Fatty acid three tails and glycerol Saturated all hydrogens Unsaturated kink (poly many kinks in one tail) bc of double bonds Phospholipid 2 fatty acid tails Hydrophilic (polar) head, hydrophobic tail 5. 1.11.3 Organization & very basic cell information 6. 4.34.4 Differences between eukaryotes and prokaryotes Eukaryotes Organelles are all membranebound (rER, sER, ribosomes, cytoskeleton, golgi, nucleus, mito); animals only lysosomes and centrioles; plants only chloroplast, cell wall, plasmodesmata, and central vacuole; cytoskeleton provides support and mobility Prokaryotes No membranebound organelles; nucleoid is where al DNA is found; only one circular chromosome; fimbriae attachment; ribosomes make proteins; plasma membrane encloses cytoplasm; cell wall and a capsule to glue cell to surfaces 7. 4.54.16 Cells covered in detail including topics such as the endomembrane system Endomembrane System Nuclear Envelope has two membranes that keep nucleus together; traffic cop of nucleus ER Smooth making of lipids; rich in ovaries and testes bc they make hormones (steroids), and livers bc it detoxifies drugs and alc, and stores calcium ions in muscle and nerve cells Rough makes phospholipids that help plasma membrane grow bc vesicles go off and add to them, bound (on rER or membrane) or secreted by cell; 1. Studded ribosomes translate polypeptide that goes into rER; modify with sugar and then foes to transport vesicle and goes to the golgi Golgi Comes to receiving end and adds to membrane of Golgi, contents move through, and then modification (glycosylation or phosphorylation) what gets added tells it where to go, buds off and vesicles is made from membrane of Golgi Lysosome digest everything; they bind to vacuoles and digest it all and can recycle things (organelles) to organic parts Plasma Membrane forms a flexible boundary between the living cell and its surroundings Phospholipid hydrophilic heads face into the cell exposed to the aqueous solutions on both sides of the membrane and out of the cell while hydrophobic tails point inward mingling together and shielding from water; cholesterol and proteins in there Nonpolar Molecules (O , 2O ) e2sily move across membrane Ions and Polar Molecules need help getting across. Some proteins form channels so the polar molecules can get through the membrane Vacuole big vesicles Not in system but part of cell: Ribosomes: Make proteins can be free in cytoplasm or bound to rER or nuclear envelope Mitochondria energy processing Chloroplast photosynthesis Cytoskeleton protein fibers; support and structure; need motor proteins Microfilaments: actin; form 3d network that supports cell bc they don’t have cell walls Intermediate Filaments: made of fibrous proteins, supercoil, anchor organelles ex. Nucleus, permanent Microtubules: mainly globular, act like train tracks for organelles to move along like lysosomes 8. 5.15.9 Membranes, passive and active transport, osmosis, exocytosis, & endocytosis Diffusion: tendency for particles of any kind to spread out evenly in an available space; molecules in a fluid are constantly in motion and they collide with each other and bounce off others and spread into open space. If the membrane is permeable to a molecule—the molecule can easily pass through membrane Equilibrium: when the number of molecules moving in one direction is equal to the number of molecules moving in the opposite direction. Concentration Gradient: substances tend to move from areas of high concentration (where a ton of molecules are) to areas of less concentration (where fewer are) Passive Transport diffusion across a membrane that requires no energy (O and C2 diffus2 easily) Facilitated Diffusion passage of a substance through a specific transport protein across a biological membrane down its concentration gradient. Transport proteins help substances that do not diffuse freely across membrane, without them certain substances wouldn’t be able to cross membrane or would take too long & wouldn’t be useful; t.proteins are specific for the substance they help No energy is used because it is a type of passive transport and works with the concentration gradient Polar molecules and ions use facilitated diffusion Aquaporin the transport protein that helps move water across membrane b/c water is polar Active Transport energy (ATP) must be expended to move a solute against its concentration gradient (toward the side where the solute is more concentrated) 1. Solute Binding solute on the cytoplasmic side of the plasma membrane attaches to a specific binding site on the transport protein 2. Phosphate Attaching (Phosphorylation) ATP transfers one of its phosphate groups to the transport protein 3. Transport Protein changes shape in such a way that the solute goes through and is released on the other side of the membrane 4. Protein reversion Phosphate group detaches and transport protein returns to its original shape Exocytosis export bulky materials ex. Proteins and polysaccharides Transport vesicle filled with macromolecules buds from Golgi goes to plasma membrane then vesicles fuse with membrane and vesicle’s contents spill out of cell. Tears are when salty solutions get exported through exocytosis. Endocytosis cell takes in large molecules; Depression in the plasma membrane pinches in and forms a vesicle enclosing material that had been outside the cell Phagocytosis: “cellular eating” Pinocytosis “cellular drinking” Osmosis with solute concentration Passive transport of water across a selectively permeable membrane in response to differing solute concentrations; Water diffuses until the solute to water concentration is equal on both sides; no solute moves just water; HS and LW vs LS and HW moves to create equilibrium Unit 3 Energy and Metabolism 1. 5.105.15 Energy, ATP, & enzymes ENERGY Cellular Respiration Exergonic bc it releases heat and ATP and then is used to do endergonic reactions in the cell Exergonic release energy; reactants have higher potential energy and release energy and products have less energy Cellulose break down release energy through heat product (glucose) with less potential energy Endergonic absorbs energy; input energy to get more energized products Metabolism total of an organism’s chemical reactions Helps enzymes Cofactor inorganic that helps enzyme; copper, iron, zinc Coenzyme organic that helps enzyme; vitamin Free floating states high entropy but together like glucose molecule has less entropy ENZYMES Induced fit weakens and contorts bond ATP Renewable resource that cells regenerate; Adenosine Triphosphate; each phosphate group is very repelling like a compressed string and therefore is very unstable; hydrolysis energy gets released; phosphorylation transfer phosphate to another molecule 2. 6.66.10 Glycolysis, Krebs cycle, chemiosmosis (may need to review 6.16.5 if you have trouble understanding these sections) Overall production of cellular respiration Heat & ATP GLYCOYSIS 9 steps catalyzed by separate enzymes Single Glucose (6 Carbon) goes in 2 G3P end product of investment and start of payoff phase 2 Net ATP, 2 NADH and 2 (3carbon) pyruvates The 2 NADH will either go a route of NADH or FADH2 and this will cause a change in the end product of ATP because FADH produces less energy CITRIC ACID CYCLE Hans Kreb 2 Turns=cycle Coenzyme A comes in and binds to Oxaloacetate to make Citrate Gets oxidized to a 5 carbon and then to a 4 carbon and then bonds get rearranged to other 4 carbon molecules and when this happens ETC Peter Mitchell Cristae are folds in mitochondrial membrane to create more space for ETC 2 does not move protons—brings in FADH and is reason why we don’t know if its 3238 Mobile electron proteins move energy molecules between protein systems Carrier molecules in each protein Electrons transported and Hydrogen ions or protons pumped out and create gradient bc they are charged and cannot get through on their own CHEMIOSMOSIS ATP Synthase is protein that pumps H+ through which synthesizes ATP About 28 ATP made FADH then it would be less than 28 3. 6.12 ATP production Glycolysis 2 NADH, 2 ATP Pyruvate oxidation 2 NADH Whole cycle 6 NADH, 2 FADH2, 2ATP Chemiosmosis 28 ATP All ATP is made by substrate level phosphorylation or oxidative Unit 4 Mitosis, Meiosis, and Genetics 1. 8.18.6 Mitosis, chromosomes, and cytokinesis CHROMOSOMES Chromatin long thin fibers of DNA that is in a loose state; can be used to make macromolecules because it is not tightly wound. When cell begins to divide the DNA coils and twists to form the tight chromosomes & it does this so that DNA can be easily moved and divided. When chromatin coils up histones help to pack the DNA and also have a huge job in gene regulation. The more tightly wound the DNA the more difficult it is to get information when it is in chromosomal form. CELL CYCLE The cell cycle an orderly sequence of events that extends from the time a cell is first formed from a dividing parent until its own division into two cells Growing phase [G1, S (duplicated chromosomes), G2] cell metabolic activity is very high and many things occur inside the cell; 90% of cells life; cytoplasm is produced; protein and organelle production is high Cellular division (M) Mitosis DNA divides and is evenly distributed between cells; unique to eukaryotes Cytokinesis cytoplasmic division Mitosis: equal division of nucleus into 2 genetically identical daughter nuclei Interphase: cell growth; synthesize new molecules and organelles; content is doubles; centrosomes found in cytoplasm each with two centrioles; chromatin form Prophase: discrete chromosomes 2 identical sister chromatids; mitotic spindle begins to form; microtubules grow out of centrosomes; centrosomes move away from each other Prometaphase: nuclear envelope fragments and disappears; microtubules from centrosomes are present at poles of mitotic spindle; kinetochore of sister chromatid attaches to microtubule from mitotic spindle which causes an agitated motion; protein motors called kinesins (&dynein) use ATP to move the chromosome toward the center of the cell Metaphase: mitotic spindle fully formed and functional; chromosomes line up on metaphase plate Anaphase: sister chromatids are separated at the two centromeres of ach chromosome; kinesin and dynein walk daughter chromosomes toward opposite poles; spindle microtubules that are attached to chromosomes shorten and ones not attached lengthen to lengthen the cell Telophase: (reverse of prophase) cellular expansion continues; nuclear envelope reforms; chromatin reforms; mitotic spindle shrinks and disappears; division of nucleus Cytokinesis: division of cytoplasm; same time as telophase 2. 8.10 and 11.2 (first three paragraphs) cellular differentiation Same genome but different gene expression 3. 8.118.17 Meiosis and related topics 8.12 Humans are said to be diploid organisms because all body cells contain pairs of homologous chromosomes. Tracking of one pair of homologous chromosomes: Each of the chromosomes is duplicated during interphase; The first division, meiosis 1 segregates the two chromosomes of the homologous pair, packing them in separate haploid daughter cells. Each chromosome is still doubled; Meiosis 2 separates the sister chromatids. Each of the four daughter cells is haploid and contains only a single chromosome from the homologous pairs. Meiosis is a type of cell division that produces haploid gametes in diploid organisms; Meiosis is preceded by the duplication of chromosomes. This single duplication is followed by 2 consecutive cell divisions, called meiosis 1 and 2; Because one duplication of the chromosomes is followed by two divisions, each of the four daughter cells resulting from meiosis has a haploid set of chromosomes half as many chromosomes as the parent cell; One of the most important events in meiosis occurs during prophase 1. Meiosis needed for sexual reproduction yields genetically unique haploid daughter cells cells with only one member of each homologous chromosome pair. The chromosomes duplicate only once during the S phase of the preceding interphase. Meiosis entails two nuclear and cytoplasmic divisions, yielding four haploid cells. Prophase 1 duplicated homologous chromosomes pair to form tetrads, sets of four chromatids with each pair of sister chromatids joined at their centromeres. Metaphase 1 tetrads are aligned at the metaphase plate Anaphase 1 pairs of homologous chromosomes separate, but the sister chromatids of each chromosome stay together. At the end of Meiosis 1, there are two haploid cells, but each chromosome still has two sister chromatids. Meiosis 2 virtually identical to mitosis in that it separates sister chromatids. Unlike mitosis, each daughter cell produced by meiosis 2 has only a haploid of chromosomes. Crossing over is an exchange of corresponding segments between nonsister chromatids of homologous chromosomes when they are in the tetrads; The sites of crossing over appear as X shaped regions each called a chiasma a place where two homologous non sister chromatids are attached to each other; Crossing over begins very early in prophase I of meiosis Three sources of genetic variability in sexually reproducing organisms: independent orientation of chromosomes at metaphase I, random fertilization, and crossing over during prophase I of meiosis. 4. 9.119.16 Genetics explored further Mendel’s laws explain inheritance in terms of discrete factors genes that are passed along from generation to generation according to simple rules of probability. Complete dominance the dominant allele has the same phenotypic effect whether regardless of the number of copies. Incomplete Dominance appearance of F1 hybrids falls between the phenotypes of two parental varieties; heterozygotes differ phenotypically from both homozygous types; DOES NOT SUPPORT Dosage dependent idea We see pink because low amount of red not blending; Null ideal piece of DNA that does not produce pigment The ABO blood group phenotype in humans involves three alleles of a single gene and four phenotypes codominant: Both alleles are expressed in heterozygous individuals (IAIB) who have type AB blood; One allele for each parent; O is universal donor and AB is universal receiver Codominance both alleles are expressed at the same exact time. Polygenic inheritance, the additive effect of two or more genes on a single phenotypic character; Creates a continuum of a trait expression; skin pigmentation in humans was controlled by three genes that are inherited separately ABO blood group is completely genetic; RBC and WBC cell counts are extremely based on environmental BCs/ml Only genetics get passed on not environmental effects EXCEPT epigenetic effects such as methylation usually passed on. 5. 9.20 Sex chromosomes We have XY or XX; birds have ZZ (male) ZW (females); social insects no sex chromosomes unfertilized (haploid) males and diploid females Scientific inquiry multiple choice Question what you ask Hypothesis what you think Dependent variable what you measure: seed growth Independent variable what you change throughout experiment: changed water amount Experimental group: too much water and no water Control group: the right amount of water Control variable what you keep the same Biology Unit 5: Evolution and Ecology Ecology: scientific studies that determine how organisms interact with their environment Biotic and abiotic factors together effect how well organism does in the environment Biotic factors: living parts of the environment (other organisms) Abiotic factors: nonliving parts of the environment (nutrients, water) Habitat (niche): specific environment an organism inhabits (includes biotic and abiotic) Levels of organization; Organism: a living thing; studies how they interact with their environment (behavior and physiology) Genus species name Population: group of individuals of the same species living in a particular region; study factors that affect the size of population like seed dispersal effect Community: population of organisms living close enough together that they could possibly interact (all biotic factors in the environment); study interspecies relations Ecosystem: abiotic and biotic factors; study chemical cycles (carbon, nitrogen) and energy flow between organisms and surroundings Landscape: a collection of ecosystems; study the flow of organisms, materials, and energy Biosphere: all of Earth that is inhibited by life Biomes: distinguished by predominant vegetation (types of plants present); provide food, shelter, reproductive, and organic material for decomposition; foundation for communities of organisms commonly found within each type of biome How plants are distributed depends mostly on climate (temp and precipitation) similar climate= similar biome; biological community not specific species Geographically separated biomes look similar b/c of convergent evolution Convergent evolution: similar phenotypic characteristics in independently evolved species living in similar environments Ex: marine reptile from million years ago looks just like todays dolphin because they both adapted to living in salt water over time—random mutations that occurred by chance and took a long time **Do not evolve to environment** Ex: marsupials evolved a pouch to nourish children not placenta because they were isolated Within biomes patchy vegetation not uniform b/c snowfall ,ay break small tress allowing broadleaf trees such as birch to grow or storms and fires can create these openings as well and biomes are becoming altered by global warming snow and ice coverage melting Human alteration of biomes creates species loss Biome types: Tropical forests: warm temp, near equator, lots of sunlight long 1112 hour days, lots of diverse species Tropical dry forest: scarce rainfall both have very Tropical rain forest: lots of rain different plant species Savanna: warm temp, grasses and scattered trees, low rainfall (lots of fires), lots of herbivores Desert: driest biome and very warm Chaparral: mild rainy winter and v dry hot summer (fires), Mediterranean climate, dense and spiny shrubs Temperate grassland: like savannah but no trees and low rainfall Temperate forests: deciduous trees (lose leaves and change color) like oak, birch, maple Coniferous forests (Taiga): evergreen trees like spruce, pine, fir (xmas trees) Tundra: prone to permafrost (ground is permanently frozen); between taiga and polar ice; artic desert Polar ice: very cold and only some mosses and other genera survive Population—have to use same resources, same environmental factors, and are likely to interact and breed with each other Boundaries of pop are defined based on species ecology and question being asked Population ecology: change in pop size and factors that regulate pop over time; can study endangered species Exponential Growth Model: (hardly ever occurs b/c necessary to have ideal conditions) New individuals in pop either are born or immigrate// individuals leave by dying or emigrate Some populations are stable over time like trees in a mature forest but some are very unstable like bacteria Idealized models determine the size of a particular population Change of population over time and under different conditions G=rN G: growth rate of population (number of new individuals per time interval/net increase) Growth rate depends on N r: per capita rate of increase (average contribution of each individual to population growth) or (max capacity of individuals with that population to reproduce) Species specific (bacteria large r, elephants smaller r) but constant N: population size (number of individuals in a pop at a particular time) Hardly ever occurs b/c pops rarely grow in an ideal environment with unlimited space and resources Jcurve sow growth when N is small Idealized picture of unlimited pop growth but all populations are limited by resource availability b/c one or more abiotic or biotic factor will limit population Fur seal: before 1925 low pop bc hunting but when hunting was controlled population grew but leveled out in 1935 because of other limiting factors like space and food Limiting factors: factors that restrict population growth Population introduced to a new environment or rebounding from catastrophic decline population size will grow exponentially Logistic Growth Model Idealized pop growth that is slowed by limiting factors as the pop size increases Exponential growth x mathematical expression that describes the effect of limiting factors on pop size K−N K ) G=rN ¿ K: carrying capacity (max pop size that a particular environment can sustain); species specific and v dependent on the resource availability; can alter k within species if in different locations; k is not fixed because biotic and abiotic factors (temp, food, parasites) will effect because resources are finite Outset N is very small compared to K but as population increases N gets larger and gets closer to K and therefore KN/K gets smaller At carrying capacity, population has reached max size S curve G=0 flatlining and K is reached More realistic because it takes in to count the limiting factors Real populations in nature: Population growth will be small when the pop size is either small or large ad highest when the pop is at an intermediate value in comparison to the carrying capacity; low pop size resources are abundant and exponentially growth occurs; however, the increase is small because the pop size is small; high pop size limiting factors oppose increases in pop size bc less food per individual or few open reproductive areas so birth rate decreases bc of limiting factors and death rate increases and after a period of time the birth rate and death rate will equal and so the pop stabilizes at the carrying capacity Density dependent factors: limiting factors whose intensity is based on population size Results in intraspecific competition conspecific (same species) individuals compete for limited resources; more individuals will be present more decline of birth ratesmore competition for food and so not enough food if you have offspring Humans j curve, exponential growth b/c birth # is outweighing death now Advances in nutrition, sanitation, and medical care changed r because death rate decreased and birth rate was the same—started during early 20 century Lots of researches thought that earth’s carrying capacity was going to be reached because of density dependent factors High pop densities in mice induced high levels of stress and pushed their puberty times back and depression of immune system—increase in death rate and decrease in birth rate of mice; crowding affects in mic were also seen in other mammal species 1962 Growth rate peaked and then from there on birth control and ppl wanted less kids and formed downward trend: demographic transition from high birth and death rate to low birth and death rate—reduced family size and women are delaying reproduction Mexico—zero pop growth (Spanish flu) Less developed nations higher rate of increase and reason why exponential rate of humans is such Age structure: broad base large proportion of children and births Population momentum: Population momentum refers to population growth at the national level that would occur even if levels of childbearing immediately declined to replacement level; explains why human population size is still increasing through the rate of increase has decreased Pop momentum predicts that human pop is going to continue to ncrease to 8 bill in the next 20 years—do we have enough resources on the planet to sustain 9 billion people? NO the pop in 2025 will need to double the amount of food present now and agricultural production is already strained and water is already used 6x over the past 70 years and rivers are drying up; much more land is needed—but take over more land than many species will go extinct Ecological footprint: (resource availability and usage) estimate of the amount of land required to provide the raw materials an individual or nation consumes—food, fuel, water, housing, water disposal, etc; total area of ecologically productive land is divided by the global pop each person has like 5 acres (2.1 global hectares); global hectare is the worldaverage ability to produce resources and absorb waste; each person takes over 4x what the average is—very large ecological deficit; US consumption of food and fuel is very high and largest ecological footprint; our ecological deficit may be just as damaging as the pop growth itself. If everyone lived the way we do in the US then we would need 4.5 Earths; Recycle and don’t waste food or water or turn lights off Stopping a rapidly expanding population is very difficult and will continue to expand for several decades even if birth rate is decreased ****Abiotic factors; natural disasters, precipitation, air quality, immigration, temp ****Biotic factors: food, illness/disease, competition between humans; antibiotic resistance Evolution Charles Darwin Galapagos Islands finch’s beak shape based on diet; formulated theory of evolution—descent with modification; species present today are descendant from ancestral species: On the Origin of Species delayed publication b/c of religion and someone else in 1858 Alfred Wallace conceived the theory of evolution independently; Wallace sent Darwin his publication and they came up with the same conclusions joint presentation; Darwin published his book; natural selection accounts for descent with modification Artificial selection only allowing individuals with certain traits to reproduce Humanbased selective process; all are varieties of a single species Wild chicken and chicken on farms for us to eat are v different All dog breeds came from a wolf at some point; artificial selection is why we have dog breeds Natural selection Observations: Members of a population often vary in their inherited traits All species are capable of producing more offspring than the environment can support Inferences: Individuals whose inherited traits give them a higher probability of surviving and reproducing in a given environment tend to leave more offspring that other individuals This unequal production of offspring will lead to the accumulation of favorable traits in a population of generations limited resources and therefore only a portion of offspring survive each generation; only tiny fraction of offspring actually complete development and reproduce; individuals who have traits that confer the ability to survive food shortage, disease, finding mates, reproducing are more likely to survive and therefore reproduce; then these individuals pass these adaptive traits onto their offspring The basis of traits are alleles adaptive alleles within a population Natural selection is very environmentally based; traits are advantages only in certain locations Random genetic mutation must occur and that is what natural selection works with Natural selection, evolution, and sexual selection Species: group of individual organisms that can reproduce viable and fertile offspring The number of populations and the number of individuals within each population varies widely based on geographic location, the life history of the species, and other factors Male donkey and female horse mule: sterile and therefore not a species bc not fertile Female donkey and male horse hinny; sterile and ^^^^ Evolution: change in the allele frequency within a population/ species over generations Individual organisms do not evolve during their environment Not a single individual becoming accustomed to a new environment Not a change in the physical appearance of an individual Most common level of evolution: natural selection Needed for natural selection preexisting genetic variation Only phenotypic features that are heritable only genetic components of variation is relevant to natural selection FE dye your hair will not affect your children bc its not heritable Variation comes from alleles which have mutated randomly Mutation is the ultimate source of genetic variation for evolution Only matters in gametes not somatic cells Mutations that alter protein function are often harmful but rarely a mutant allele produces a selective advantage to an individual Occurs way more often when environment changes so that alleles that were once not advantages are now advantages—rare white rabbit helps in snow climate Chromosomal mutations are often harmful errors in meiosis can also account for genetic variation Mutated repeated segments of DNA can persist over many generations Ancestral mammals has a single odor detecting gene and meiosis errors resulted in duplication and mice have about 1300 odor detecting genes Prokaryotic mutations can spread quickly—bc they have a short generation time; all haploid so only one allele so allele has an effect instantly Mutation rate in animal and plants is 1/100000 on average bc of long generation time, low mutation rate, and diploid genomes prevent most mutations form significantly affecting genetic within a population or species from one generation to the next—takes a longer time for the effect In sexually reproducing organisms unique combination of alleles that each individuals inherits from mother and father Mutations come from crossing over, independent orientation, and random fertilization Natural selection does not produce genetic variation Natural selection must work with whatever genetic variation exists/ must already be present Survival of the fittest is ill—more like reproduction of the fittest Genetic variation mutation, meiosis, sexual reproduction not natural selection Evolution is not goal directed; will not lead to the perfectly adapted organism; result of environment to environment; phenotypic characteristics in one environment may be beneficial but neutral or harmful in a different area; natural selection does not cause beneficial mutations to occur BONUSES: Sexual selection form of natural selection in which individuals with certain traits are more likely than other individual to obtain mates Sexual dismorphism females and males look different within a species: in size, forms of ornamentation, and colors Usually males are more ornamented sex Intrasexual selection individuals compete with members of the same sex for mates; physical combat and displays deers running at each other to fight for female; males involved in competeions and displays Intersexual selection females choose their mates based on certain ornamentation Indicator of male quality whoever wins is a higher quality male and so female would want the winner who is more healthy and fit; males that win often produce more offspring because they win the male; energy for coloration are most fit Seahorses males get pregnant female gets chosen by size reversal of how sexual selection occurs Handicap signals long tail that is hard to live if the male can survive with handicap signal must be high quality male
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