Biology101 Exam #2 Study Guide
Biology101 Exam #2 Study Guide BIO101
Popular in Biology 101
Popular in Biology
verified elite notetaker
This 17 page Study Guide was uploaded by emilyecclestone on Thursday February 11, 2016. The Study Guide belongs to BIO101 at Wake Forest University taught by Dr. Carole Gibson in Fall 2015. Since its upload, it has received 36 views. For similar materials see Biology 101 in Biology at Wake Forest University.
Reviews for Biology101 Exam #2 Study Guide
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: 02/11/16
Biology 101: Exam #2 Regenerative Medicine 1. What is it? • Process of replacing, engineering, or regenerating human cells, tissues, or organs to restore or establish normal function, o Dr. Anthony Atala 2. How does it work? • Take stem cells, figure out what signals they need, use them to build new tissues (tissue engineering) • “Scaffolding”- generally extra cellular matrix proteins • Extra Cellular Matrix o Molecules that fill spaces between cells o Builds scaffolding § Natural mold for building new organs using cells from their own body 3. What does it do? Why is it important? • Types o Gene therapy o Genetic screening o Cloning o Genetic modification o Transgenic Stem cells 1. What is it? • Undifferentiated/Unspecialized cells o They haven’t decided which gene to turn on o Immortal cells o Self-renewing o Potency 2. How does it work? • 1. Multipotent o Differentiate into only a few cell types § i.e. only different kinds of skin cells or blood cells o Many are available, BUT have limited use o Examples: adult stem cells and umbilical stem cells • 2. Pluripotent o Come from the zygote or very early embryoà totipotent stem cell o Can develop into any kind of cell § Including trophoblast cells of the blastocyst o Hard to findà very few available o Embryonic stem cells: § Undifferentiated pluripotent § Can grow fast and long § Cells inside embryo when it’s a blastocyst • Blastocyst is destroyed when stem cells are removed when 4-5 days old • 3. Induced Pluripotent Stem Cells o Genetically altered adult stem cells § Induced/prompted in a lab to take on characteristics of embryonic stem cells o Can behave and express some of same genes that are normally expressed in embryonic stem cells BUT not exact duplicate o No blastocyst, no fertilization 3. What does it do? Why is it important? • Regenerating cells; using natural scaffolding/used to create new organs via your own cells • Examples of how stem cells are used: o Retinal Cells- replace dead cells in retina to cure diseases like glaucoma and macular degeneration o Skin Cells- create new skin cells to replace damaged ones (burn victims) o Nerve Cells- repair damage caused by spinal injuries to enable paralyzed victims to regain movement o Blood Cells- bone marrow transplants for cancer patients who are immune-compromised as a result of chemotherapy • For Stem Cell Use o Cells grown are genetically identical to the adultàno difficulties with rejection of new cells o Can be taken from embryos that have stopped developing and would have died anyways o Cells are taken at a stage when embryo has no nervous systemàcan arguably feel no pain o Can develop into any type of cell o Potential to repair damage of failure caused by injury or disease o Further potentialàthey could become a complete organ and/or be used to create a new organ (natural scaffolding) • Against Stem Cell Use o Requires creation of an embryo that is destroyed § At what point do we afford the right to life? o If embryo was not destroyed, then be a clone of the individual o More research needed on adult stem cells o Stem cells can develop into [cancerous] tumor cells Induced pluripotent stem cell 1. What is it? • Adult somatic cell • Can take any cell regardless of age of person and it can be redesigned/redirected to become a stem cell 2. How does it work? • Turns on 4 genes that are normally turned on in embryonic cells o behaves like embryonic stem cells • generated by a manipulation of a differentiated somatic stem cell 3. What does it do? Why is it important? • Pluripotent adult stem cells are hard to find (very few available) • Can become many different types of cells • If correct genes are activated, any adult cell can become a stem cell, thus becoming a blastocyst • Why important- o Using somatic cellà stem cell without even having an embryo because the stem cell is from a person’s own body Cloning 1. What is it? • Clone: o A group of genetically identical organisms or a group of cells artificially derived from a single parent cell. o Cloningàprocess 2. How does it work? • Somatic Cell Nuclear Transfer o Method of [reproductive] cloning using differentiated cells o Replacing the nucleus from a specialized cell o Process § Nucleus from an egg cell is removed • Removing genetic information from cell § The egg is fused with the nucleus from a somatic cell of another donor • Making the egg cell diploid § Electric shock is delivered to stimulate the egg to divide § Once this process has begun, egg is implanted into the uterus of a surrogate § Developing embryo will have same genetic info as the donor that contributed the diploid nucleusà a clone • Therapeutic human cloning o Purpose- create an embryo to supply stem cells for medical use o Same format as reproductive cloning, BUT when the cell is a blastocyst the ball is broken and stem cells cultured 3. What does it do? Why is it important? • Creates an embryo that is genetically identical to the donor cell • Different uses of cloning: o Reproductive cloning § Animal cloningàsave endangered species, copy elite animals o Therapeutic cloning § Embryonic stem cellsàmake transplantable cells, damaged tissues o Transgenic techniques § GMOsàresearch models, xenotransplantation • Issues: o Is it ethical? § Involves creation and destruction of human embryos • At what point do we afford the right to life? o Short tangent sequences à shortened life § Telomeres are sequences of short nucleotide repeats at end of chromosomes § Ex: Dolly the sheep Somatic cell nuclear transfer 1. What is it? • [cell] cloning process 2. How does it work? • Replacing the nucleus of an egg with a nucleus rom a specialized egg 3. What does it do? Why is it important? • Creates an embryo that is genetically identical to the donor cell Human Genome Project 1. What is it? • James Watson! • International cooperative venture established to sequence the complete human genome 2. How does it work? • Reading your gene sequence • Genetic screening o Testing an individual for the presence or absence of a gene 3. What does it do? Why is it important? • For/Advantages o Right to know if you have a genetic defect that leads to a disease or a carrier for a disease o Future understanding of many genetic diseases o Development of genomic libraries o Production of gene probes to detect sufferers and carriers of disease o Pharmaceutical production o Family planning o Prenatal diagnosis • Against/Disadvantages o Invasion of privacy o Potential discrimination/stigma associated with having a certain gene (i.e. employment/medical insurance, etc.) o Abort of fetus if problems are found Genetically Modified Organisms (GMOs) 1. What is it? • Genetically altered by humans/scientists • Also known as transgenic organisms o Organisms that carry a foreign gene 2. How does it work? • Outside gene added to and organism to “improve” it (ex: food) • Engineering animals to enhance production o Sheep producing more wool • Engineering animals to produce desired products o Producing certain grade of milk 3. What does it do? Why is it important? • Widely debated o Is it safe/healthy? o Is it ethical? à Does it kill other organisms in the process? • Benefits: o Allows for introduction of a characteristic that wasn’t present in the gene pool § Selective breeding could not have produced desired phenotype o + nutrient value o + places plants can grow § Disease resistance, pest resistance, etc. o + productivity o Genetic diversity of crops § If all crops have the same genes and aren’t resistance to certain diseases, if the disease spreads then it would wipe out the whole population • Negatives: o Could have currently unknown harmful effects o Accidental release of transgenic organism into the environment may cause competition with native plant species o Possibility of cross pollination o Long term risks unknown Transgenic 1. What is it? • Transgenic organism is one that has had foreign DNA inserted into its genome • Transgenic is generally used to refer animals (GMO is for plants) • Possible because the genetic code is universal 2. How does it work? • Step 1: microinjection into nucleus of fertilized egg (use technique of recombinant DNA gene) à all we have to do is get that gene into the genome • Step 2: Transfer foreign gene into embryonic stem cells, add the cells to blastocyst • Gene of interest is inserted into the egg cell then into “surrogate mother” 3. What does it do? Why is it important? • Widely debated à is it ethical? • Positives: o Transgenic animals are used for “pharming” à generating animals that can produce pharmaceutically important products in their milk or animals that are nutritionally enhanced o Transgenic animals are also important for research § i.e. for the study of the function of particular genes, their proteins, and how they are regulated. Gene Therapy 1. What is it? • Treatment of genetic disorders with recombinant DNA • Treatment that aims to cure human disease by replacing defective genes with functional ones o BUT only diseases that are caused by single gene defect 2. How does it work? • In cases where an individual has a disease caused by a single gene defect, a vector can be used to transport a normal copy of the gene to the affected cells • Vector is usually a disabled virus inserted into the individual affected / embryo to replace defective genes with new ones • Example of a gene therapy protocolàto replace defective genes in white blood cells o 1. Remove white blood cells o 2. Use vector to insert normal gene into chromosome o 3. Replace cells into patient o 4. Repeat every few months 3. What does it do? Why is it important? • If successful, this eliminates the symptoms of the disease. • Can prevent the individual who is affected by a disease from passing it on to their offspring • Examples of gene therapy: o Cystic fibrosis- dysfunction of lungs and other organs o SCID (immune deficiency)- replaced gene allows for the production of the enzyme ADA, which helps a person fight off infection o Cure for Thalassemia- blood disorder, inability to make proper hemoglobin. Result, anemia. Cure is in sight • Positives: o Prenatal diagnosis o Family planning o Huntington’s disease detection • Issues: o Should we be changing nature? o Is it too expensive? o Is it too dangerous? o Where do we draw the line? What is normal? o Slippery slope o Cheating (performance enhancing drugs) Photosynthesis 1. What is it? • Process by which plants and other autotrophs (organisms that capture energy of sunlight by photosynthesis) use energy of sunlight to make energy-rich molecules using CO2 and water. 2. How does it work? • Photosynthesis captures sunlight to make “food” (energy) o “Photo” § Chloroplasts capture the energy of sunlight § Water is split à releases oxygen as a by-product o “Synthesis” § Captured energy is used to convert CO2 into energy- rich sugar glucose • Light Dependent Reaction: o Solar energy is converted to chemical energy in the form of a reduced electron acceptor o 2 separate “photosystems” § Photosystem II • Sends it excited electrons to an ETC couple to ATP Synthaseàgenerates ATP § Photosystem I • Electrons from Photosystem I replace electrons lost in Photosystem II • Passes its excited electron to an electron carrier that uses it to reduce CO 2 o Passes to the electron carrier NADP • NADP accepts electron and grabs a protonàforms NADPH • NADPH passes electrons onto CO 2 • Light Independent Reaction: o Calvin Cycle o NADPH reduces CO 2 § Uses its H to reduce CO 2 o Reduced CO mo2ecules are combined to make glucose 3. What does it do? Why is it important? • Inputs: Sunlight + H2O+ CO =2O 2 • Outputs: O2 + Glucose (C6H1206) • Goal of photosynthesis is to make glucose sugar for energy • Convert sunlight to energy • Almost all oxygen in the atmosphere comes from photosynthesis o Life as evolved to be dependent on oxygen because it is required for cell respiration Cell Respiration 1. What is it? • Controlled release of energy from organic compounds in cells to ATP o Using the energy to add a P to ADP à ADP+P=ATP 2. How does it work? • Begins with glucose, which is broken down during glycolysis • Glycolysis occurs in the cytoplasm o Produces a net gain of 2 ATP o Produces 2 pyruvate • Anaerobic respiration o Fermentation § Produces lactic acid • Aerobic respiration o Starting with Kreb’s Cycle § Occurs in the mitochondria § Net yield of 1 ATP, 3 NADH, 1 FADH • These are used in the ETC o Occurs in the mitochondria o Yields a total of 36 ATP 3. What does it do? Why is it important? • ATP is the energy source the cells use to do work Glycolysis 1. What is it? • Breakdown of sugar • Oxidation of glucose in the cytoplasm 2. How does it work? • Occurs in the cytoplasm • Glucose is broken down into two 3-carbon sugars. o Molecules are oxidized § Results in removal of H and passed onto NAD o Energy is releasedà 2 ATP 3. What does it do? Why is it important? • First steps in the oxidation of glucose • Some yeast and bacteria live anaerobically, and these organisms derive their energy from glycolysis Pyruvate 1. What is it? • End product of glycolysisà pyruvate 2. How does it work? • Broken down into CO2 and water and a large amount of ATP is formed 3. What does it do? Why is it important? • Used to generate small amounts of energy provided by glycolysis • Conversion of pyruvate replenishes the levels of the hydrogen acceptor for glycolysis to occur o Resultsà lactate in animals; ethanol & CO2 in plants fungi (yeasts), bacteria Fermentation 1. What is it? • Process involved in cell respiration • Series of chemical reactions that takes place after glycolysis in the absence of oxygen • Conversion of pyruvate into ethanol and CO2 2. How does it work? • O2 is not neededàanaerobic respiration • Anaerobic respiration: o No oxygenàETC can’t work § Last electron acceptor of ETC is oxygen § If no working ETC to accept H from NADH, NADH gives H back to the pyruvate • Pyruvate is reduced by the NADH formed in glycolysis. • In animals, the product is lactate. • When oxygen becomes availableàlactate gives H back to NAD, the NADH goes on to the mitochondria, and the product, pyruvate, continues to be oxidized. 3. What does it do? Why is it important? • Some yeast and bacteria live anaerobically, and these organisms derive their energy from glycolysis. • When organisms undergo fermentation, the products are ethanol and CO2. Aerobic respiration 1. What is it? • Process involved in cell respiration • Series of reactions that occurs in the presence of oxygen and converts energy stored in food into ATP 2. How does it work? • Oxygen is present • 1. Glycolysis • 2. Krebs Cycle • 3. ETC • Uses pyruvate from glycolysis • Both pyruvate and NADH will go to the mitochondria o Pyruvate continues to be oxidized • NADH passes its H to the ETC • NAD is recycled • As pyruvate is oxidizedà H that is removed is passed to NADàNADH • NADH passes H to ETC • Electron from H is passed from one molecule to the next o Along ETC • Final electron acceptor is oxygen 3. What does it do? Why is it important? • Glucose + oxygen à energy + carbon dioxide + water • Both the pyruvate and the NADH will go to the mitochondrion, where the pyruvate continues to be oxidized and the NADH passes its H to the electron transport system, and NAD is recycled. Electron Transport chain 1. What is it? rd • Process involved in cellular respirationà 3 stage in aerobic respiration • A series of molecules embedded in the inner mitochondria membrane 2. How does it work? • Needs O2 to function - • High energy electrons (e ) are passed from NADH down a chain of molecules o Powers a series of reactions that channels energy into the formation of many ATP molecules • Each step along, a small amount of +nergy is released • Energy is used to move protons (H ) into space between the two membranes o Establishes protein gradient 3. What does it do? Why is it important? • Produces the bulk of ATP during aerobic respiration • Maintains proton gradientà contain potential energy Evolution 1. What is it? • Change in the frequency of gene alleles in a population from one generation to the next. • Can be adaptive or non-adaptive 2. How does it work? • These two processes must take place for evolution to occur: o A source of variation between individuals of one species § Crossing over, mutation, independent assortment o A change in allele frequency in the gene pool of a population § Natural selection 3. What does it do? Why is it important? • Population is more adapted to the environment • Evidence for evolution: o Anatomy § Homologous structures • Structures that are anatomically similar but have been adapted for different purposesàsuggest common ancestry o Embryology § Shared features between early amphibian embryosàcommon ancestry o Artificial selection/Selective breeding § The frequency of a certain allele in a population can be changed o Vestigial traits § Suggest that organisms at one time had a need for a certain structure, but no longer need it to succeed in their environment o Fossil record § Shows gradual changes in species over great periods of time Natural selection 1. What is it? • The process through which adaptive evolution occurs, by which certain inherited traits make it easier for individuals to live, grow, reproduce by changing the genetic makeup of populations over time • Credited by Charles Darwin and Alfred Wallace 2. How does it work? • Genetic diversity is necessary for natural selection • Population has a diversity of alleles for most of its traits o Alleles have arisen by gene mutations • Change in the environmentàcreate a situation where one of these alleles gives an advantage to those who have it o More likely to survive and reproduce § Allele will be represented at a greater frequency in the next generation • Not only changes phenotypes, but also genotypes 3. What does it do? Why is it important? • Evolutionary mechanism à adaptation • Population is more adapted to the environment • Increases likeliness of individuals survival Non-adaptive evolution 1. What is it? • Change in frequency of a certain allele is not due to a selective pressure • Any change in allele frequency that does not itself lead a population to become more adapted to its environment 2. How does it work? • Due to either a loss of diversity in the population o Population bottleneck § When a population is reduced to just a few members and many diverse alleles are lost § Founder effect • When a small number of members of a population leave and establish their own population • Other causes: o Mutation o Genetic drift o Gene flow 3. What does it do? Why is it important? • Evolutionary mechanism à adaptation Genetic drift 1. What is it? • Changes in allele frequencies of a population between generations; tends to have more dramatic effects in smaller populations than smaller ones 2. How does it work? • Smaller population gets separated from larger oneàevolves indifferently • Population has been set aside 3. What does it do? Why is it important? • Explains how a population can break into 2 species • Also can explain distribution of alleles (allele frequency) • Will have greater effect in smaller populations • Tends to decrease genetic diversity of a population o Some alleles are lost and others have 100% frequency Founder effect 1. What is it? • One of the examples of non-adaptive evolution • A small number of members of the population leave and establish their own population 2. How does it work? • Occurs when a small group of “settlers” (founders) splits from a main population and establishes a new one à type of genetic drift • Newly established population may have lower genetic diversity than the original population 3. What does it do? Why is it important? • Evolutionary mechanism à adaptation • May have certain alleles that are now represented with a greater frequency than in the larger population Artificial selection 1. What is it? • Encouraged selection of some traits, but discourage some traits forced by humans/scientists 2. How does it work? • Selective breedingà when man directly intervenes in the breeding of animals to produce desired traits in offspring o Examples: § Breeding… • Horses for speed (racehorses) vs. strength and endurance (draft horses) • Dogs for herding (sheepdogs), hunting (beagles), or racing (greyhounds) • Cattle for increased meat production or milk • Zebras in an attempt to retrieve the coloration gene from the extinct Quagga 3. What does it do? Why is it important? • Scientifically selected traitsàchanging the characteristics of animals by artificial means • Domesticated breeds can show significant variation compared to their wild counterparts o Demonstrating evolutionary changes in a much shorter time frame than might have occurred naturally Gene flow 1. What is it? • Process of non-adaptive evolution • A source of variation within a given population 2. How does it work? • Alleles move from one population to another o Via immigration and/or emigration 3. What does it do? Why is it important? • Can/may increase genetic diversity in a population • Once population has lost genetic diversity, there are only two ways it can be reintroduced: o Mutation o Gene flow Mutation 1. What is it? • An alteration in gene sequence(s) • A permanent change to the genetic composition of an individual 2. How does it work? • Substitution of one nucleotide dilation of one or more nucleotide inversions • Introduces new alleles into a population • Substitution • Depletion • Inversion 3. What does it do? Why is it important? • Evolutionary changes in a gene pool can have lasting consequences for a population à becomes more adaptive to its environment Variation • Members of a population are not clones of each other, rather a variety exists • Initially due to… o Mutation o Separation of homologous chromosomes in the production of gametes • Reproduction promotes variation o Independent assortment o Crossing over • Some versions will be better adapted to the particular environment than others Speciation 1. What is it? • Species definition à a group of organisms that can interbreed and PRODUCE FERTILE OFFSPRING • Genetic divergence of populations leading overtime to reproductive isolation and formation of new species. o Ligers (lions + tigers) à sterile offspring, can’t reproduce 2. How does it work? • Reproductive isolation: two of the same species of the population can no longer SUCCESSFULLY mate • Post-zygotic isolation à horse + donkey = mule can’t produce sex cells à genetic line ends 3. What does it do? Why is it important? • Natural selection can lead to allopatric speciation Darwin • 1895 book à origin of species by Natural Selection o Identified this process • HMS Beagle à 1830s voyage exhibition • Observed how organisms were built for their habitat o Most known example à FINCHES § Breaks adapted to food available to each island § Increased fitness/adaptation to environment • Individuals don’t evolve à natural selection produces evolutionary change because it changes genetic composition of populations à occurs between interactions and environment. • Basic principles: o 1. Traits are inherited o 2. There is a variation in traits (phenotypes) o 3. Some traits make an organism more adapted to it environment o 4. Those more adaptedàsurvive to reproduce Recap: Mechanism of How allele Adaptive/ Non How diversity is Evolution frequency adaptive affected changes Natural Selection Individuals w/ Adaptive Usually decreases favorable alleles – unfavorable reproduce alleles may be preferably eliminated from increasing allele population frequency Mutation New alleles are Non-adaptive Increases – new created randomly alleles are introduced to population Gene Flow Alleles move from Non-adaptive Increases – new one population to alleles are added another to the population Genetic Drift Allele frequencies Non-adaptive Usually decreases change due to – alleles maybe change of events eliminated from population
Are you sure you want to buy this material for
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'