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

Bio 120 study guide (FINAL EXAM) **cumulative**

by: Jamisha Evans

Bio 120 study guide (FINAL EXAM) **cumulative** BIO 120

Marketplace > Western Kentucky University > Biology > BIO 120 > Bio 120 study guide FINAL EXAM cumulative
Jamisha Evans
GPA 3.71

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

My laptop stopped working on me this week, which is where all my study soup files are. i have finals to study for as well so im sorry if my study guide isnt very good. i still included information ...
Sahi, Shivendra
Study Guide
Bio, 120, study, guide, final, exam
50 ?





Popular in Biology

This 25 page Study Guide was uploaded by Jamisha Evans on Monday May 2, 2016. The Study Guide belongs to BIO 120 at Western Kentucky University taught by Sahi, Shivendra in Winter 2016. Since its upload, it has received 89 views. For similar materials see BIOL CONC CELLS METAB GENETICS in Biology at Western Kentucky University.

Similar to BIO 120 at WKU


Reviews for Bio 120 study guide (FINAL EXAM) **cumulative**


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: 05/02/16
Bio 120 study guide (FINAL EXAM) Biology Study Guide Test 2 Chapter 4: Prokaryotic cells ad Eukaryotic cells  Cell structure • Discovery of cells ♦ Cells were discovered by Robert Hooke in 1665 • Cell theory ♦ All organisms are composed of cells ♦ Cells are the basic unit of life ♦ Cells rise from preexisting cells • All cells today represent a continuous line of descent from the first living cells • Cell size ♦ Cell size is limited. Most cells are relatively small due to the reliance on diffusion of substance in and out of cells ♦ Rate of diffusion can be affected by… • Amount of surface area available • Temperature • Concentration gradient • Distance • Microscopes ♦ Not all cells are visible to the naked eye • Resolution- minimum distance two points can be apart and still be distinguished as two separate points ◊ Objects must be 100µm apart for the naked eye to be able to distinguish the objects as two rather than one. ♦ There are two broad groupings of life according to morphology 1. Prokaryotes: Lack a membrane-bound nucleus 2. Eukaryotes: have nucleus(membrane bond organelles) ♦ There are three domains according to phylogeny • Bacteria- Prokaryotic • Archaea-Prokaryotic • Eukarya- Eukaryotic ♦ Prokaryotic cells-structural overview • All prokaryotes lack membrane-bound nucleus. • Archaeal cell structure is relatively poorly understood • Bacterial cells vary greatly in size and shape, but most contain several structural similarities… ◊ Plasma membrane ◊ A single chromosome ◊ Ribosomes which synthesize proteins ◊ Stiff cell wall • Most prokaryotic cells species have one chromosome which contains a long strand of DNA and a few supportive proteins. • In addition to the large chromosome, many bacteria contain plasmids ◊ Plasmids are small supercoiled circular DNA molecules which are found in the nucleoid ◊ Plasmids usually contain genes that help the cell adapt to the environment (example: Drug resistance) ♦ Prokaryotic cells- Internal Structure • Other structures are contained within the cytoplasm… ◊ Ribosomes: consist of RNA molecules and protein for protein synthesis. All prokaryotic cells contain ribosomes. ◊ Photosynthetic Membranes: located inside prokaryotes. ♦ Prokaryotic Cells- External Structure • Flagella: tail like structure on cell surface which spins to move the cell. The flagella is the prokaryotic cells mechanism of movement.( in most prokaryotes) • Cell wall: tough fibrous layer that surrounds the plasma membrane. Contains peptidoglycan • Capsule: an additional layer outside the cell wall composed of lipids or glycolipids ♦ Bacterial organelles • Bacteria contain internal compartments called organelles (“little organs”) ◊ Organelle: membrane bound compartment inside cell that contains enzymes or structures specialized for a particular function • Organelles are common in eukaryotic cells ♦ Eukaryotic cells- Introduction • Many are multicellular, others are unicellular • Larger than prokaryotic cells • It is difficult for molecules to diffuse across the entire cell because of the large size of eukaryotic cells (refer to above: Rate of diffusion is affected by… surface area availability) ◊ Large cell volume is broken up into smaller membrane bound organelles to solve this problem ♦ Eukaryotic cells compared to prokaryotic cells • There are four key differences between eukaryotic and prokaryotic cells… 1. Eukaryotic chromosomes are found in a membrane bound compartment called nucleus 2. Prokaryotic cells are smaller than prokaryotic cells 3. Eukaryotic cells contain extensive mounts of internal membrane 4. Eukaryotic cells feature a diverse and dynamic cytoskeleton  Cell structure ♦ Nucleus : contain genetic information • Nucleolus- located inside nucleus. Where ribosomal RNA synthesis takes place • Nuclear envelope- also known as nuclear membrane ◊ Double membrane • In eukaryotes DNA is divided into multiple linear chromosomes ◊ Chromatin- Consist of chromosomes and proteins ♦ Endomembrane system: series of membranes throughout the cytoplasm which divides the cell into compartments where different cellular functions occur • One of the fundamental distinctions between eukaryotes and prokaryotes ♦ Rough endoplasmic reticulum • Structure… ◊ Network of membrane-bound tubes and sacs studded with ribosomes. • The ribosomes give it its rough texture • Rough ER is continuous with the nuclear envelope • Function... ◊ Synthesize proteins with help of ribosomes ◊ New proteins are folded and processed in the rough ER lumen ♦ Smooth endoplasmic reticulum • Structure… ◊ Lacks ribosomes associated with the rough ER • Function… ◊ Used to break down poisonous lipids ◊ Reservoir for Ca2+ ions ♦ Golgi apparatus • Structure… ◊ flattened tack of interconnected membranes • Function… ◊ in packaging ◊ distribution of molecules that are synthesized at one location and used at another, within or outside the sell ◊ Distribute proteins to different parts of the cell where they are needed ♦ Ribosomes • Structure… ◊ Non- membranous ◊ Large and small subunits which contain RNA (specifically rRNA) molecules and proteins ◊ Can be attached to rough ER or free in cytosol( aqueous component of cytoplasm in cell) ◊ Made up of ribosomal RNA (rRNA)- protein complex • Function… ◊ Protein synthesis • Protein synthesis also requires messenger RNA (mRNA) an transfer RNA (tRNA) ♦ Microbodies: enzyme-bearing membrane-enclosed vesicles • Peroxisomes ◊ Contain enzymes involved in oxidation of fatty acids and produces a byproduct called Hydrogen peroxide (H2O2) ◊ Specialized peroxisomes in plants called glyoxysomes are packed with enzymes that oxidize fats to form a compound that can be stored as energy for the cell. ♦ Lysosomes • Structure… ◊ Single membrane bound structures found in animal cells, containing about 40 different digestive enzymes • Function: ◊ Used for digestion and waste processing • How are materials delivered to lysosomes ◊ Materials are delivered to the lysosomes by three processes • Phagocytosis: indigestion of bacteria or other material (type of endocytosis) • Autophagy: destruction of cells in body • Receptor-mediated endocytosis: specific molecules are ingested into cell (type of endocytosis) ◊ Endocytosis: process by which the cell membrane can pinch off a vesicle to bring outside material into cell • Pinocytosis is a type of endocytosis, along with phagocytosis and receptor-mediated endocytosis, which brings fluid into the cell ♦ Vacuoles • Structures: ◊ Membrane bounded structures in plants with various functions depending on the cell type ◊ There are different types of vacuoles… • Central vacuoles in plant cells • Contractile vacuole of some fungi and protists • Storage vacuoles • Function: ◊ Some contain digestive enzymes ◊ Some are specialized for digestion ◊ Most vacuoles are used for water storage and or storage of ions to help cell maintain normal volume. ♦ Mitochondria: found in all types of eukaryotic cells • Structure: ◊ Bound by membranes (double membrane) • Outer membrane • Intermembrane space • Inner membrane has cristae( ) ♦ On surface of inner membrane and also embedded within it are proteins hat carry out oxidative metabolism • ATP synthesis (oxidative metabolism) • Matrix • Function: ◊ Have own DNA and manufacture their own DNA ribosomes ♦ Chloroplast • Structure: ◊ Double membrane structure found in most plant and algae cells. They also contain their own DNA. (Do these characteristics sound familiar? These characteristics are the same as the characteristics found in mitochondria) ◊ Contain membrane bound, flattened structure called thylakoids, which are stacked into piles called grana. Outside the thylakoids is the solution called the stroma • Function: ◊ Convert light energy to chemical energy. In other words, they perform photosynthesis. **Endosymbiosis proposes that some of today’s eukaryotic organelles evolved by a symbiosis arising between to cells that are free-living. A prokaryote as engulfed by another cell and became a part of it which was the precursor of modern eukaryotes.** Example: Mitochondria and chloroplasts ♦ Eukaryotic cell walls • Plants and protest cell walls are made up of cellulose • Fungi cell walls are made up of chitin • Plants have primary and secondary cell walls ♦ Cytoskeleton: network of protein fibers found in all eukaryotic cells • Function: ◊ Supports shape of cell ◊ Keeps organelles in fixed locations ◊ Constantly forming and disassembling ◊ Aids in cell movement and transport of materials within cell • Cytoskeleton has 3 types of fibers ◊ Microfilaments ◊ Microtubules ◊ Intermediate filaments ♦ Centrosomes • Region surrounding centrioles in almost all animal cells. Centrioles are usually not present in plants and fungi ♦ Extracellular matrix (ECM) • Structure: ◊ Protective layer over cell’s surface linked to cell’s cytoplasm by integrin’s. Collagen may be abundant in ECM • Function: ◊ Secrete an elaborate mixture of glycoproteins into space around ECM  Cell communication ♦ Cell-to-cell interactions • Surface proteins give cells identity ◊ Cells make contact, read each other, and react ◊ Major histocompatibility complex (MHC) proteins- recognition of self and non-self-cells by immune system. • Self-antigen binds to self-receptor and non-self-antigen binds to non-self receptor ___________________________________________________________________________ Chapter 5: Membranes  Membrane structure • Made up of phospholipids arranged in a bilayer • Fluid mosaic model (proposed by Singer and Nicholson)- model of membrane ♦ Cell-surface receptors: Receptor proteins in PM receives chemical message ♦ Cell-to-cell identity markers: PM membrane proteins which identify cell types ♦ Cell-to-cell adhesion proteins: cells use specific proteins to glue them together  Channel proteins ♦ Ion channels: some of the membrane protein can function as ion channel proteins • They allow the passage of ions • Gate channels: open or close in response to electrical or chemical stimulus • Moves from high to low concentration. Therefore energy is not needed because it relies in concentration gradient (passive transport).  Carrier proteins ♦ Types of carrier proteins used in active transport are… • Uniporters- move one molecule at a time ( HELPFUL TIP: Uni- means one) • Symporters- move two molecules in same directions • Antiporters- move two molecules in opposite directions ___________________________________________________________________________ Chapter 10: How cells divide  Cells go through a cell cycle consisting of four phases (G1, S, G2 & M)  Functions of mitosis • Growth • Wound repair • Asexual reproduction  Cell cycle • Cell cycle: the orderly sequence of events that occurs from the formation of a eukaryotic cell through the duplication of its chromosomes to the time it undergoes cell division ( the order of the cell cycle is (G1,S,G2,M) ♦ G1 phase: cell growth and preparation for replication INTERPHASE ♦ S phase: DNA replicates/DNA synthesis ♦ G2 phase: prepares for nuclear division ♦ M phase: division of nucleus • Mitosis (M Phase) is a continuous process with five subunits ♦ Prophase • Spindle apparatus assembles • Nuclear envelope ♦ Prometaphase • Occurs after disassembly of nuclear envelope • Microtubule attachment • Chromosomes begin to move to center of cell ♦ Metaphase • Alignment of chromosomes along metaphase plate • Future axis of cell ♦ Anaphase • Centromeres split • Sister chromatids pulled apart ♦ Telophase • Spindle apparatus disassembles • Chromatids arrive to respective poles • Nucleolus reappears in each new nucleus • Pretty much the opposite of events in prophase  Cytokinesis • Usually occurs immediately after mitosis • Cytoplasm divides to form two daughter cells • Each cell has its own nucleus and complete set of organelles  Cell-cycle checkpoints • There are 3 distinct cell cycle checkpoints ♦ G1: determines whether the cell will continue through the cycle and divide, or exit and enter G0 ♦ Factors that affect whether cells pass the G1 checkpoint: 1. Cell size 2. Nutrient availability 3. Social signals from other cells 4. Health of DNA ♦ G2: cells stop growing here if chromosome replication has not proceeded properly or if DNA is damaged ♦ M:cell ceases during metaphase if chromosome are not properly attached to mitotic spindle ♦ The three checkpoints prevent the division of cells that are damaged or that have Problems Biology 120 test 3 Chapter 6 & 7: Energy, Metabolism & Cellular respiration & Fermentation • Thermodynamics : branch of chemistry concerned with energy changes ◊ Laws of thermodynamics ♦ First law: energy can only be change form but cannot be created or destroyed. The total amount of energy in the universe remains constant ♦ Second law: energy transformations are spontaneously to convert matter from a more ordered/less stable form to a less ordered/ more stable from. Entropy is constantly increasing. • Feedback inhibition ◊ The end-product of pathway binds to an allosteric site on enzyme that catalyzes the first reaction in pathway. ♦ Raw materials and energy are not wasted ◊ Changes enzyme so that the initial enzyme cannot bind to it which as a result the whole pathway shuts down.  Enzymes: biological catalysts • Most enzymes are proteins • The shape of an enzyme stabilizes a temporary association between substrates • Enzymes are not changed or consumed in a reaction  The steps of cellular respiration • Cellular respiration: Any suit of reactions that produces ATP in an electron transport chain. • Cellular respiration has four steps: ◊ Glycolysis- glucose(6 Carbon) is broken down to pyruvate (3 Carbon) ◊ Pyruvate processing- pyruvate is oxidized to form acetyl CoA ◊ Citric acid cycle- Acetyl CoA is oxidized to CO2 ◊ Electron transport and chemiosmosis.- series of compounds that transfer electron donors to electron receiver via redox reactions. • Glycolysis ◊ First step in glucose oxidation ◊ Feedback inhibition regulates glycolysis ♦ Feedback inhibition: occurs when an enzyme in a pathway is inhibited by the product of that pathway. ♦ Cells that can stop glycolic reactions when ATP is abundant can conserve their stores of glucose for times when ATP is scarce. ◊ Glycolysis occurs in the cytoplasm. ♦ The glucose molecule is broken down to 2 molecules of pyruvate. Each molecule of pyruvate consists of 3 carbon. ◊ The remaining reactions occur in the Mitochondria ♦ Pyruvate produced during glycolysis is transported from the cytosol (part of the • Pyruvate processing ◊ Second step in glucose oxidation ◊ Catalyzed by the enzyme pyruvate dehydrogenase in the mitochondrial matrix ◊ In the presence of oxygen, pyruvate undergoes a series of reactions that result in the product molecule acetyl coenzyme A (CoA). ♦ Remember, during glycolysis, glucose (6C) is broken down to 2 molecules of pyruvate each consisting of (3C). So therefore pyruvate processing results in 2 molecules of acetyl (CoA) ◊ During these reactions another NADH molecule is synthesized • Citric acid cycle ◊ Third step in glucose oxidation ◊ The acetyl CoA produced by pyruvate processing enters the citric acid cycle ◊ Located in mitochondrial matrix ♦ Each acetyl CoA is oxidized to two molecules of CO2 ◊ Some of the potential energy release is used to: ♦ Reduce NAD+ to NADH ♦ Reduce FAD ( Flavin…) to FADH2 (electron carrier) ♦ Phosphorylate GDP to GTP which is later converted to ATP ♦ Citrate is the first molecule in the citric acid cycle ♦ The citric acid cycle completes glucose oxidation ◊ To summarize… ♦ The citric acid cycle begins with acetyl CoA and ends with CO2 ♦ The potential energy that is released is used to produce NADH and FADH2 and ATP ♦ When energy supplies are high the cycle slows down. • Free energy changes NADH and FADH2 ◊ For each glucose molecule that is oxidized to 6 CO2, the cell reduces 10 molecules of NAD+ to NADH and 2 molecules of FAD to FADH2 and produces molecules of ATP by substratelevel phosphorylation. ◊ The ATP can be used directly for cellular work. However most of glucose’s original energy is contained in the electrons transferred to NADH and FADH2, which then carry them to oxygen (the final acceptor of electron transport system) • The electron transport chain ◊ Fourth step in cellular respiration ◊ Occurs in the cristae (the inner mitochondrial membrane) ◊ The proteins involved in these reactions make up what is called an electron transport chain ◊ Oxygen is the final electron acceptor in the electron transport chain (receives final electron) ◊ The transfer of electrons along with protons to oxygen forms water. ◊ ETC produces a proton gradient (higher concentration of protons outside of inner membrane of mitochondria) • Chemiosmosis hypothesis ◊ The ETC pumps protons from the mitochondrial matrix to the intermembrane space ◊ The proton motive force from the electrochemical gradient can be used to make ATP in process called chemiosmosis ♦ Chemiosmosis: movement of ions across a selectively permeable membrane from an area of high concentration to low concentration ◊ ATP Synthase ♦ ATP Synthase : complex enzyme ♦ Protons flowing through ATP synthase result in subunits change shape and catalyze (cause) the phosphorylation of ADP to ATP. ♦ ATP synthase produces 25 of the 29 ATP molecules produced per glucose molecule during cell respiration  Aerobic and anaerobic respiration • All eukaryotes and prokaryotes use oxygen as the final receptor of the electron transport chain in the process of aerobic respiration. • Some prokaryotes, especially those in oxygen-poor environments use other electron receptors in the process of anaerobic respiration.  Fermentation • Cellular respiration can to occur without oxygen. ◊ Fermentation is a metabolic pathway that generates NAD+ from NADH which allows glycolysis to continue producing ATP in the absence of oxygen. ♦ Fermentation occurs when pyruvate or a molecule derived from pyruvate accepts electrons from NADH ◊ Fermentation is extremely inefficient compared to cellular respiration ♦ Fermentation produces only two ATP molecules per glucose molecule while cellular reparation produces about 29 ATP molecules peer glucose molecules • Types of fermentation ◊ Lactic acid fermentation: pyruvate accepts electrons from NADH. Lactate and NAD+ are produced. Occurs in muscle cells ◊ Alcoholic fermentation: pyruvate is converted to acetaldehyde and CO2, acetaldehyde accepts electrons from NADH. Ethanol and NAD+ are produced. Occurs in yeast ______________________________________________________________________________ Chapter 8: Photosynthesis  Photosynthesis overview • Energy for all life essentially comes from photosynthesis • Key structure in photosynthesis is chloroplast Chloroplast ◊ Double membrane structure ◊ Thylakoid membrane: contains chlorophyll and other photosynthesis pigments. The pigment are clustered into photosystems ♦ Grana: stacks of flatt4ened sacs of thylakoid membrane. The stroma lamella connect grana. ♦ Stroma: semiliquid surrounding thylakoid membranes ♦ Stomata: controls CO2 availability. Allows CO2 in and O2 out  Stages of photosynthesis • Light dependent reactions ◊ Require light ◊ Make ATP and reduce NADP+ to NADPH (high energy molecule) • Light independent reactions (Dark reaction) ◊ Includes carbon fixation ◊ May or may not occur in presence of light ◊ Uses ATP and NADH form light dependent reactions to synthesize organic molecules from CO2  Photosystems • Consist of 2 major elements: antenna complex and reaction center ◊ Antenna complex: captures photons from sunlight and channels the to the reaction center chlorophylls ◊ Reaction center: when chlorophyll I reaction center absorbs a photon of light, an electron is excited to a higher energy level  Light dependent reaction • Occurs in thylakoid membrane of chloroplast • Involves photosystem I (P700) and II (P680) ◊ Begins with photosystem II ♦ Photosystem II generates ATP ♦ Electrons lost form photosystem II oxidize water producing free electrons and oxygen gas. ◊ Photosystem I generates NADPH • Noncyclic type of photophosphorylation (electron flows in a noncyclic fashion; Z scheme) • ATP (photophosphorylation) and NADPH synthesis ◊ Photophosphorylation: ATP is being synthesized in photosynthesis • Source of electrons is photolysis of water • In light dependent reaction… ◊ Photon of light is captured by a pigment molecule ◊ Energy is then transferred to the reaction center ◊ Electrons move through carriers to reduce NDP+ to NADH ◊ ATP created by hydrogen proton gradient • B6-f is the proton pump embedded in the thylakoid membrane  Light independent reactions • Occurs in stroma of chloroplast • Involves only photosystem II • Cyclic (electrons flow in a cyclic fashion) • Uses NADPH and ATP form light reaction • Involves carbon fixation (Calvin cycle) ◊ Calvin cycle is also called C3 pathways because the starting molecule is a 3 carbo molecule ( PGA) ◊ Enzyme ribulose bisphosphate carboxylase/oxygenase or rubisco; RuBP ( this enzyme can fix carbon or oxygen) ◊ Calvin cycle has 3 steps 1. Carbon fixation: RuBP (5C)is added to CO2 producing PGA (3C) (key step in Calvin cycle) 2. Reduction: PGA is reduced to G3P which is used for synthesis of glucose. 2 G3P are used to for synthesis of glucose. (glucose is not a direct product of the cycle) 3. Regeneration of RuBP: G3P is used to regenerate RuBP  Importance of Rubisco enzyme • Can fix carbon or oxygen ◊ Great amount of oxygen mean Rubisco will fix oxygen (oxygenase) ◊ Great amount t of carbon means rubisco will fix carbon( carboxylase) • Most abundant enzyme on earth • Inefficient  Other types of photosynthesis • There are other types of photosynthesis besides C3 pathway (C4 and CAM) • Comparing and contrasting C4 and CAM pathways ◊ Both use C4 and C3 pathways ◊ C4 photosynthesis occurs in two different cells ♦ C4 pathway occurs in mesophyll cells and C3 pathway occurs in bundle sheath cells ◊ C3 photosynthesis is separated by time ♦ C4 pathway occurs at night and the C3 pathway occurs during day Biology 120 test 4 Chapter 11 (Sexual reproduction and meiosis)  An overview of meiosis  Meiosis reduces chromosome number by half which is why it is called reduction division  Just before meiosis begins, each chromosome in the diploid (2n) parent cell is replicated  After replication, each chromosome consists of identical sister chromatids attached at the centromere.  Meiosis consists of two cell divisions (meiosis I and meiosis II)  Meiosis I  Diploid parent cell produces two haploid daughter cells  Homologs in each chromosome pair separate and go to different daughter cells  Although the daughter cells are haploid (n) each chromosome still consist of two identical sister chromatids  No replication (S phase) after meiosis I (between meiosis I and II)  Meiosis II  The sister chromatid of each chromosome separate and go to different daughter cells  Meiosis II is similar to meiosis II  The four haploid daughter cells produced by meiosis II also have one of each type of chromosome, but now the chromosomes are replicated  Remember: there is no replication between meiosis I and meiosis II. Replication only occurs before meiosis I during Interphase.  In meiosis chromosomes are reduced from 2n to n (diploid to haploid)  In animals, the diploid daughter cells that comes from the haploid original cell, becomes gametes through a process called gametogenesis.  Fertilization  Fertilization results in a diploid zygote  When two haploid gametes fuse during fertilization, a full complement of chromosomes is restored.  The cell that results from fertilization is diploid (zygote 2n)  Each diploid individual receives a haploid chromosome set from both its mother (maternal chromosomes) and its father (paternal chromosomes)  Phases of meiosis  Interphase- DNA replication/synthesis  Meiosis I: separation of homologous chromosomes  Prophase I  Metaphase I  Anaphase I  Telophase I  Meiosis II: separation of sister chromatids (like mitosis)  Prophase II  Metaphase II  Anaphase II  Telophase II ***Same names just different roman murals (I and II) ***  Phases of Meiosis in detail  Interphase: Chromosomes in parent cell at an expanded (non-visible) state and from sister chromatids.  Meiosis 1  Early Prophase I: Chromosomes become visible, nuclear envelope disappears and spindle apparatus forms. The two homologous chromosomes pair (synapsis).  Late Prophase I: Sister chromatids cross over and exchange genetic information. Spindle apparatus attaches to the centromere.  Metaphase I: Chromosome are aligned at equatorial plate by the spindle apparatus  Anaphase I: homologs separate and move to opposite side of cell  Telophase and cytokinesis: spindle apparatus disappears and nuclear envelope reappears. Chromosomes move to opposite sides of the cell and then the cell divides. ** Begins with one 2n; Diploid (parent cell) and Ends with two n; Haploid (daughter cells)  Meiosis II  During Meiosis II, practically the same processes occurs as the process in Meiosis I except, that there are two cells and each cell has only one set of chromosomes. ** Begins with two n; Haploid (daughter cells) and Ends with four n; Haploid (daughter cells)  Crossing over  Occurs only during Prophase I and contact is maintained until Anaphase I.  At each point where crossing over occurs, sister chromatids get physically broken at the same point ad attached to each other.  Results in exchange of genetic information between homologous chromosomes which results in recombinant chromosomes (combination of traits that differ from those found in parents.)  Can occur at many locations of the synapsed homologs  Clarification: during crossing over, non-sister chromatids of the homologues chromosomes cross over and attach to each other.  Remember that sister chromatids are either of the two chromatids formed by replication of a single chromosome. Notice that the sister chromatids are crossing over each other and produce gametes with a different genetic makeup than their parents.  Chiasmata: site of crossing over  Crossing over allows the offspring produced to be genetically different from parents instead of a clone. This is we may greatly resemble our parents but we don’t look exactly like them.  Errors in Meiosis  Failures during meiosis will produce games with the incorrect number of chromosomes.  Nondisjunction: failure of chromosomes to move to opposite pols during meiosis I or II.  Produces gametes with less or more number or chromosomes.  Aneuploid gametes: Gametes with improper number of chromosomes.  Can lead to miscarriages, or offspring disabilities (Down syndrome, Turners syndrome, etc.) ____________________________________________________________________________________ Chapter 12 (Patterns of Inheritance) NMT= Non-Mendelian Trait  Gregor Mendel’s experiment system th  19 century monk  Studied heredity  Heredity: transmission of traits from parents to their offspring.  Trait: a characteristic of an individual  Studied dichotomous traits and how they are passed on to their offspring.  2 possible alleles for each trait  The combination one has ( 1 from om, 1 from dad) is called genotype (genetic makeup)(ex: Aa.. etc)  Physical make-up is called phenotype (ex: Brown hair)  Homozygous: 2 matching alleles  Heterozygous: 2 different ales (non-matching) EXAMPLE: Homozygous: aa or AA Heterozygous: Aa  Gregor sought to answer specific questions  Why do offspring resemble their parents  How does transmission of traits occur  Two hypothesis were formulated to try to answer these questions  Blending inheritance : parental traits blend and offspring have intermediate traits  Inheritance of acquired characteristics: modified parental traits passed on to offspring  First model organism in genetics: Garden pea plants  Genetics: branch of biology that focusses on inheritance of traits  Mendel chose garden pea plant as model organism to study genetics because  Easy to grow  Short reproductive cycle  Produces large number of seeds  Mating’s are easy to control  Traits are easily recognizable  How did Mendel arrange mating  Self- fertilization: pollinate self (pea plants can do this)  Mendel prevented the peas from fertilizing themselves by removing the male reproductive organs (contains pollen) for each flower. He used the pollen to fertilize the female reproductive organs of flower on different plants. This process is called cross fertilization.  What traits did Mendel study?  Seven easily recognizable traits (he observed the phenotypes)  Pod shape  Pod color  Seed color  Seed shape  Flower and pod position  Stem length  Mendel worked with pure lines (homozygous )which produced identical offspring when self pollinated  Mendel’s experimental method  3 stages  Produce true breeding strains for each trait  Cross fertilize true breeding strains  Allow hybrid offspring to self-fertilize and count number of offspring showing each form of the trait.  Monohybrid crosses  Cross that studies only 2 variations of a single trait (EXAMPLE: seed shape; wrinkled or smooth  In every monohybrid cross he got a 3:1 ratio after the F2 generation. 3 dominant and 1 recessive  F1 generation (first filial generation)  Mendel crossed 2 homozygous breeding strains (RR and rr) (parent generation)  The results: Each offspring was heterozygous dominant (Rr and Rr) (F1 generation)  F2 generation ( Second filial generation)  Offspring from first filial generation were used to create the F2 generation (Rr and Rr)  The results: The phenotypic ratio: 3 round: 1 wrinkled The genotypic ratio: 1 homozygous dominant: 2 heterozygous dominant: 1 homozygous recessive (RR, Rr,Rr and rr)  Mendel’s conclusion from his experiment  The plants did not show intermediate traits. The traits were distinct.  Dihybrid crosses  Cross that studies two separate traits in a single cross  True breeding lines for two traits  RRYY (round and yellow) x rryy (wrinkled and green)  F1 generation shows the dominant phenotypes for each trait (Seed shape; Round, Seed color; Yellow)  F1 generation  RRYY and RRYY were crossed (parent generation)  The results: RrYy and RrYy (F1 generation)  F2 generation  RrYy and RrYy from F1 generation crossed  The results: RRYY, Rryy, rrYy, rryy Phenotypic ratio: 9:3:3:1 Genotypic ratio: 1:1:1:1  Genes, alleles and genotypes  Hereditary determinates for a trait are now called genes  Each individual has two versions of each gene called alleles.  The different alleles are responsible for the variation in the traits that Mendel studied.  Alleles are an individual’s genotype (allelic makeup). The genotype majorly affects the phenotype (physical makeup)  Alleles don’t blend.  The presence of alleles do not mean guarantee expression  Rr: In this case little “r” is shown but not expressed this is a dominant genotype because the dominant trait is expressed.  In order for a genotype to be recessive both alleles have to be present ( little “r”; rr)  Principles of segregation  During gamete formation two alleles for a gene segregate and are rejoined at random. One from each parent.  Mendel developed the principle of segregation  Pedigree charts  Used to track the inheritance patterns in families.  Incomplete dominance: heterozygote intermediate between 2 homozygotes (EX: pink flowers(offspring) from white and red flowers(parents)) (NMT)  Codominance: heterozygote shows some aspect of the phenotypes of both homozygotes (EX: type AB blood; A and B are codominant) (NMT)  Epistasis: offspring doesn’t have an alleles from parents (R.A Emerson crossed 2 white variants of corn; result was 9 purple corn and 7 white corn (NMT)  Extensions to Mendel  Mendel’s model of inheritance assumes that each trait is controlled by a single gene  Each gene has only two alleles  There is a clear dominant recessive relationship between alleles.  Most genes do not follow this criteria  Polygenic inheritance: Multiple genes are involved in controlling the phenotype of a trait. These traits show a continuous variation (EX: Eye color, Human height) (NMT)  Pleiotropy: An allele that has more than one effect on the phenotype (EX: diseases like sickle cell; multiple symptoms can be traced back to one defective allele) (NMT)  Multiple alleles :May be more than 2 alleles for a gen in a population (EX: ABO types in humans (3 alleles) ) (NMT) ______________________________________________________________________________ Chapter 14: The genetic material (Review Nucleic acids Ch.3)  Fredrick Griffith  Studied streptococcus pneumonia, a pathogenic bacterium causing pneumonia  S strain: causes pneumonia  R strain: does not cause pneumonia  He injected live S strain, live R strain, heat killed S strain, and heat-killed S+R strain into a mouse. Only the live S strain, and heat-killed S+R strain killed the mouse. This concluded that DNA is genetic material and not protein.  Chargaff  Amount of Adenine=amount of thymine  Amount of cytosine=amount of guanine  Rosalind Franklin  Identified the 3D structure of DNA with X-ray diffraction studies.  Discovered DNA is helical  Watson and crick  Used evidence form Chargaff and Franklin  Created the helical structure of DNA  DNA double helix  Antiparallel  Complementarity of bases  A forms 2 hydrogen bonds to T  C forms 3 hydrogen bonds to G  To remember this, think of how C is the third letter in the alphabet (3 H bonds) , and remember it pairs with G. then remember that A to T has one bond less.  Semiconservative  Combination of daughter and parent genetic material on one DNA double helix.  Determined by Meselson and Stahl  DNA replication  Requires…  Something to copy (template)  Something to do copying (enzyme)  Building blocks to make the copy (deoxyribonucleotide subunits)  Steps in DNA replication  Initiation: replication begins  Elongation: new strands of DNA synthesized by DNA polymerase  Termination: replication stops  Key information about DNA replication  DNA polymerase (III) is the key replicating enzyme  Adds new bases to 3’ end of existing strands  Can only synthesize in 5’ to 3’ (limitation)  Requires help of RNA primer which is removed one replication is complete  Helicase: uses energy form ATP to unwind DNA  Topoisomerase: prevent supercoiling  DNA gyrase (type of Topoisomerase)  DNA replication is semidiscontinuous  This is because the leading strand is synthesized continuously while the lagging strand is synthesized discontinuously  Okazaki fragments on lagging strand which are connected by RNA primer and made by DNA polymerase III. The RNA primer later Removed by DNA polymerase I and replaced with DNA fragments  Okazaki fragments are complementary to the lagging strand template  DNA polymerase I is like the “proof reader” which makes sure there were no mistakes made.  Eukaryotic DNA replication  More complicated than prokaryotic replication because  There is a large amount of DNA in multiple chromosomes  Linear structure  Similar enzymology  Requires new enzymatic activity for dealing with ends only  Multiple origins of replication for each chromosome  Initiation requires more factors to assemble both helicase and primase complexes onto the template then load the DNA polymerase with its sliding clamp unit.  Telomeres  Specialized structures found on the ends of eukaryotic chromosomes (protects ends of chromosomes)  Limitation: unable to replicate lagging strand  DNA repair  2 types  Specific repair: targets single kind of lesion in DNA and repairs only that damage  Photo repair: repair damage caused by UV light  Nonspecific: repairs multiple kinds of lesions in DNA  Excision repair: damaged region is removed and replaced by DNA synthesis. Undamaged strand is used as template ______________________________________________________________________________ Chapter 15: Gens and how they work  Central dogma  DNA to RNA to protein  DNA: information storage  mRNA: information carrier  Proteins: active cell machinery  DNA to mRNA (transcription; which occurs in the nucleus)  mRNA to protein (translation ;which occurs in the cytoplasm)  Exceptions to central dogma  Sometimes info flows in the opposite direction- from RNA back to DNA  Reverse transcriptase is used  Francois Jacob and Jacques Monod  Proposed that RNA molecules act as a link between genes  Genetic code  Specifies relationship between sequence of nucleotide bases in mRNA and the corresponding sequence of amino acids in a protein  Transcription and translation in eukaryotes  Transcription and translation are separated. mRNA are synthesized in the nucleus and then transported to the cytoplasm for translation by ribosomes. *** To help you study, take the practices quizzes on McGraw Hill at the end of the chapters included in the study guide (Dr. Sahi class)***


Buy Material

Are you sure you want to buy this material for

50 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."

Anthony Lee UC Santa Barbara

"I bought an awesome study guide, which helped me get an A in my Math 34B class this quarter!"

Steve Martinelli UC Los Angeles

"There's no way I would have passed my Organic Chemistry class this semester without the notes and study guides I got from StudySoup."

Parker Thompson 500 Startups

"It's a great way for students to improve their educational experience and it seemed like a product that everybody wants, so all the people participating are winning."

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.