BiologyFinalStudyGuideCh8on.pdf Biology 103
Popular in Introductory Biology I
verified elite notetaker
verified elite notetaker
verified elite notetaker
verified elite notetaker
verified elite notetaker
verified elite notetaker
Popular in Biology
This 8 page Study Guide was uploaded by Alicia Muir on Wednesday August 3, 2016. The Study Guide belongs to Biology 103 at George Mason University taught by Gwendolyne Y Fondufe (P) in Summer 2015. Since its upload, it has received 16 views. For similar materials see Introductory Biology I in Biology at George Mason University.
Reviews for BiologyFinalStudyGuideCh8on.pdf
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: 08/03/16
Chapter 8: 1. Cell division: reproduction, creates 2 “daughter” cells, duplicates chromosomes and sorts new chromosomes. Used for reproduction of singlecelled organisms, growth of multicellular organisms, repair and replacement of cells, and sperm and egg production. 2. Asexual: produces a genetically identical cell who inherits all genes from one parent. (like begets like). Sexual: produces cells with similar genes to parents, with variations. Inherits unique sets of genes from each parent. (like begets like somewhat). 3. Prokaryotes (bacteria; typically circular and much smaller than eukaryotes) reproduce through Binary fission: type of asexual reproduction consisting of three stages: duplicate chromosomes and separate the copies, elongate cells and move the copies, and divide into two daughter cells. 4. False: Chromosomes are composed of DNA and proteins that maintain its structure and function. 5. Chromatin is long, thin, threadlike DNA and proteins that coils up and condenses into chromosomes in order to prepare for division. 6. Before a cell divides, a chromosome replicates producing 2 identical sister units called chromatids joined together at the centromere. 7. The cell cycle is the sequence of events in a cell’s life from when it is first born to when it divides. It consists of interphase and mitotic phase. It spends most of its life in interphase. 8. G1: growth, increase in cytoplasm. S: duplication of chromosomes (S stands for synthesis of DNA). G2: growth, preparation for division. 9. See study guide 10. Mitotic phase is composed of mitosis (division of nucleus) and cytokinesis (division of cytoplasm). 11. Stages of mitosis: prophase, prometaphase, metaphase, anaphase, telophase (telophase often overlaps with cytokinesis). 12. Interphase: cytoplasmic contents double, chromosomes duplicate, two centrosomes form. Prophase: 13. A spindle is composed of microtubules and is required to divide and move the chromosomes. Produced by centrosomes. 14. The microtubules in animal cells originate from the centriole. 15. Cytokinesis is the process where the cytoplasm is divided into two separate cells. In animal cells, a cleavage furrow forms from the outside inward and deepens to separate the contents into two cells. In plant cells, a cell plate forms and grows from the inside outward to the edges to divide the contents into two cells. 16. Mitosis produces 2 identical daughter cells. The daughter cells are diploid cells. 17. True: while cells such as skin cells and those lining the digestive tract divide frequently, liver cells do not divide unless the liver is damaged, and nerve cells do not divide at all. 18. Cell division is affected by the presence of essential nutrients, growth factors (proteins stimulate division), densitydependent inhibition (crowded cells stop dividing), and anchorage dependence (the need for cells to be in contact with a solid surface to divide). 19. See 18 20. Cell cycle control system: cycling set of molecules in the cell that trigger and coordinate key events in the cell cycle. Checkpoints are critical control points that signal to stop an event or signal for an event to proceed in the cell cycle. 21. G1(aka restriction checkpoint or “the point of no return”), G2, and M checkpoint. 22. A cell that gets the go signal at the G1 checkpoint gets entry into the S phase, completes the cell cycle, and divides. 23. If a cell does not get the go signal at the G1 checkpoint it leaves the cell cycle and enters the nondividing G0 phase. 24. Nondividing cells such as muscle and nerve cells are in the G0 phase. 25. True: growth factors are proteins secreted by cells that stimulate other cells to grow and divide. 26. Cancer develops when a normal cell is converted to a cancer cell. Cancer cells divide fast and spread to other tissues by escaping controls on the cell cycle. Scientists aren’t exactly sure how cancer cells function. 27. Benign tumours remain at the original site, and malignant tumors spread to other locations. 28. Carcinomas originate in external or internal body coverings. Leukemia originates from immature white blood cells within the blood or bone marrow. 29. Metastasis is the spread of cancer cells beyond their original site. Treatments include radiation, surgery, or chemotherapy. 30. True: a faulty stimulative or inhibitive signaling system. 31. True: Mutations in genes that stimulate or inhibit cell division contribute to cancer. 32. False: a single mutation will not always result in a cancer cell (explains why elderly are more likely to get cancer, because they are more likely to have mutations). 33. Carcinogens: a substance capable of causing cancer. Examples: radiation, tobacco smoke, diet, pollution, or viruses. 33) The roles of mitosis: growth, asexual reproduction, and replacement of damaged and lost cells. 34. A diploid cell has 2 sets of chromosomes, while a haploid cell has one set. 35. Somatic cells have a diploid number of chromosomes, while sex cells have a haploid number of chromosomes. 36. Homologous chromosomes/autosomes/sex chromosomes 37. False: autosomes are not always identical. 38. Males are XY and females are XX 39. Gametes are haploid and somatic cells are diploid 40. True 41. True 42. True 43. Stages: interphase, meiosis 1, meiosis 2 44. Synapsis: (similar) homologous chromosomes come together as pairs. Crossing over: nonsister chromatids exchange genetic material. Tetrad: term for 4 chromatids that are united (one pair of homologous chromosomes) chiasmata: where nonsister chromatids meet during crossing over, formed during synapsis. 45. Synapsis and crossing over happen during prophase 1. 46. Crossing over allows for genetic diversity 47. Meiosis 1: 2 ‘haploid’ cells. Normal number of chromosomes in each cell after meiosis 1. 48. No, the replication of DNA does not occur between meiosis 1 and 2. 49. Have same phases, but in meiosis align using synapsis to combine like chromosomes and align by tetrads in metaphase in order to have crossing over (swapping genetic material) unlike random alignment in mitosis 50. After Meiosis II: 4 haploid daughter cells, chromosomes are not duplicated 51. See 49. In meiosis, tetrads separate in anaphase 1, as opposed to sister chromatids separating in mitosis. See powerpoint 8.14 52. Genetic variation: independent orientation, random alignment of chromosomes so there is an equal probability of the maternal or paternal chromosome facing a certain pole. Random fertilization: random combination of eggs and sperm. Crossing over: exchange of corresponding segments between nonsister chromatids. 53. zygote: a fertlized egg; it is diploid. 54. 2^3 possibilities (8 possible combinations) 55. Genetic recombination: production of new combinations of genes due to crossing over. 56. Karyotype: ordered display of magnified images of an individual’s chromosomes arranged in pairs. Useful to observe chromosome pairs, number, and structure (can see nondisjunction). 57. Nondisjunction: failure of chromosomes or chromatids to separate normally during meiosis. Can happen in meiosis 1 if both members of a homologous pair go to one pole, or in meiosis 2 if both sister chromatids go to one pole. 58. Down syndrome: extra copy of chromosome 21 is the cause (3 copies are inherited) , Klinefelter syndrome: , Turner syndrome: 59. Genders: XYY male, XXY male (klinefelter), XOfemale (turner), XXX female 60. Symptoms: Down syndrome: facial features, short stature, heart defects, susceptibility to other infections, developmental disabilities. 61. Also called trisomy because it inherits 3 copies of chromosome 21. 62. True: chance of having a child with down syndrome increases with maternal age. 63. Polyploidy: having more than two chromosome sets. Found more in plants than animals. 64. Deletion: loss of a chromosome segment, duplication: repeat, inversion: reversal of a segment, translocation: attachment of a segment to a nonhomologous chromosome that can be reciprocal. 65. Somatic cells Chapter 9: 1. Pangenesis: pangenes come from all parts of the organism and are incorporated into eggs and sperm, characteristics acquired during parent’s lifetime can be transferred to offspring. Blending: hereditary materials mix in forming offspring. Gene: carriers of traits, located on chromosomes. Trait: variant for a character. Allele: alternative versions of genes. Locus: location of an allele on the chromosome. Dominant: determines appearance. Recessive: is present but has no effect. Genotype: genetic makeup. Phenotype: outward appearance. Homozygous: same alleles. Heterozygous: different alleles. Monohybrid cross: testing for one character. Dihybrid cross: examining two different characters. Carrier: having a certain trait. True breeding: passing the physically expressed traits to offspring. Punnet square: means of discovering probability of different genotypes and phenotypes. 2. P is parents and F is offspring. 3. Possible gametes: 4. 50%, 50%, 0% 5. The kids will be heterozygous for a widow’s peak. 6. Law of segregation: the two alleles segregate from each other in the formation of gametes. 7. They will have 75% a widow’s peak and 25% a straight hairline. 8. Number mess up; see 6 9. Test cross: mating an individual with another with a known genotype to discover the other’s genotype. 10. Law of independent assortment: genes of different traits assort independently of one another in the formation of gametes. 11. Independent assortment; segregation 12. Possible gametes: 13. a. 6/8, b. ⅛, c. ⅛, 14. Practice problem 15. More practice 16. Pedigree chart: shows inheritance of a trait in a fmaily through multiple generations 17. Autosomal recessive traits: affects both sexes equally, heterozygotes are carriers, affected parents will have affected children, traits tend to skip generations, probability of occurence increases with inbreeding. 18. Switched with 17 19. True: most human genetic disorders are recessive 20. There is a 50% chance their offspring will have huntingtons disease. 21. Cystic fibrosis is a lethal autosomal recessive disorder. 22. There are genetic tests that can be done with modern technology, such as amniocentesis and chorionic villus sampling. 23. Incomplete dominance: when no one allele is dominant over the other, and an intermediate phenotype is expressed (pink roses) 24. A testcross is not required to determine genotypes in incomplete dominance. 25. Switch with 24; genotypic and phenotypic ratio: 1:2:1 26. Hypocholesterolimia: people dominant homozygous (HH) have normal number of LDL receptors, and therefore normal blood cholesterol levels. Heterozygotes have intermediate numbers of LDL receptors, and homozygous recessive have no LDL receptors and 5X the number of cholesterol in blood. 27. Multiple allele system: when more than 2 alleles exist; i.e., blood type 28. Codominance: neither allele is dominant so both are expressed. Ex. AB blood type 29. Carbohydrates present: A: A, B: B, AB: A and B, O: Neither 30. Genotypes: A= IaIa or Iai, B=IbIb or Ibi, AB= IaIb, O= ii 31. During transfusions blood types should match because if they dont the body will produce antibodies that bind to the unfamiliar carbohydrates and cause more blood clots. 32. False; a person of type AB will produce no antibodies. 33. Pleiotropy: one gene influences many traits 34. Sickle cell disease: sickle cell gene makes red blood cells produce irregular hemoglobin; cells have a sickle shape. Symptoms; clogged blood cells, weakening of body bc sickle cells are destroyed (anemia), pain and fever, kidney failure, joint problems, and more. 35. Sickle cell trait: requires only one gene 36. Heterozygotes are protected from malaria because the infected cells become sickleshaped and are thus destroyed 37. In heterozygotes, the alleles of sickle cell are codominant 38. Polygenic inheritance: one phenotypic character is controlled by more than one gene. 39. True: the environment can affect many traits 40. SRY is found on Y chromosome and triggers the develpment of testes 41. True: a sperm cell can have a y or x, while all eggs contain a single x 42. sexlinked : all genes and their traits on the sex chromosome. Xlinked: majority of sexlinked traits, only on x chromosome. 43. Xlinked recessive traits: more males than females are affected, for a duaghter to be affected her dad must be and her mom must at least be a carrier, a son can be affected even if both parents have the normal phenotype, if a woman is affected, her sons will be and her daughters will be carriers. 44. B Chapter 14: 1. Speciation: the process by which one species splits into two or more species 2. Biological concept: a group of populations whose members have the potential to interbreed in nature and produce fertile offspring. Morphological :classifies organisms based on observable physical traits and can be applied to asexual organisms and fossils. Issues with subjectivity. Ecological: defines a species by its ecological niche, such as what they eat or where they live. Phylogenetic: defines species as the smallest group of individuals that share a common ancestor. 3. Reproductive isolation: prevents members of different species from mating with each other. 4. Hybrids: the offspring of 2 clearly distinct species (grolar bears) 5. Biological concept is problematic because of hybrids, and because it can’t be applied to fossils or asexual prokaryotes. 6. Morphological applies to asexual and sexual reproduction. 7. Reproductive barriers: isolate gene pools of species; prezygotic (before fertilized eggs form) or postzygotic (after eggs form) 8. Prezygotic: habitat, temporal, behavioral, mechanical, gametic. Postzygotic: reduced hybrid viability/fertility, hybrid breakdown. 9. Habitat isolation; prezygotic. 10. Allopatric speciation: populations of the same species are geographically separated, isolating their gene pools. 11. Sympatric speciation: a new species arises within the same area of a parent species. 12. Number mix up; no 7 13. 3 factors that reduce gene flow between populations: polyploidy (an organism has more than 2 sets of complete chromosomes; often creates a sterile hybrid which can then reproduce asexually to make a species with 2n= the sum of the diploid numbers of both parents), habitat differentiation (adaptations evolve according to the needs of the environment), or sexual selection (choosing mate by appearance). 14. Polyploidy: having more than 2 complete sets of chromosomes. 15. True: polyploidy can occur within a species by selffertilization. 16. True: failure of chromosomes to divide after cell division could double the number of chromosomes in a cell from diploid to tetraploid. 17. False; self fertalization in tetraploid plants produces plants that are fertile and can reproduce with other tetraploids or with a parent (diploid) plant. 18. Formation of a tetraploid is instantaneous speciation because a new species which is reproductively isolated from its parent species is produced in a single generation. 19. True: most polyploidy species arise from hybridization. 20. False; infertile hybrids CAN reproduce asexually. 21. False: polyploidy is most commonly found in plants, but occasionally occurs in animals. 22. Polyploidy; habitat differentiation and sexual selection 23. True: bread wheat is a result of hybridization and polyploidy. 24. False; most species on earth are thought to have evolved from allopatric speciation. 25. Adaptive radiation: the evolution of many diverse species from a common ancestor. 26. Isolated island chains provide opportunities for adaptive radiations because they are physically diverse, are far enough away to allow species to evolve in isolation, and close enough to allow occasional dispersions. 27. True: darwin’s finches are an example of adaptive radiation. 28. Hybrid zone: regions in which members of different species mate and produce some hybrid offspring. 29. 3 outcomes: reinforcement (strengthening reproductive barriers), fusion (weakening reproductive barriers), and stability (continued formation of hybrids). 30. D 31. Punctuated equilibria: species change the most as they arise from the ancestral species, and experience relatively little change after. Gradual: change evolves gradually. 32. ? No, because sympatric speciation occurs when another species appears without geographical isolation, and allopatric speciation requires isolation. Chapter 15.615.17 1. Macroevolution: major changes recorded in the history of life over long time spans. 2. Crust;mantle. 3. Plate tectonics: theory that earth’s crust is divided into irregularly shaped plates that float on the mantle. 4. Continental drift: movements in the mantle cause the plates to move. 5. Pangea: supercontinent was formed when plate movements brought all the landmasses together. Laurasia: northern landmass that was created in mesozoic era when pangea split. Gondwana: southern landmass. 6. False; continents continue to shift today 7. Mass extinctions: large numbers of species become extinct due to global environmental changes. Examples of causes: volcanic eruptions, large asteroid, possibly human activity in environment (?). 8. Consequences: affect biological diversity, remove species with advantageous features forever. Can take 510 million years to return to previous state. 9. 5, possibly 6th now. 10. 6th mass extinction because current extinction rate is 1001000 times the normal rate seen in the fossil record, due to human actions modifying the global climate. 11. Adaptive radiations occur after mass extinctions because organisms adapt to fill new ecological niches. 12. True 13. Evodevo: examines how slight genetic changes have major morphological consequences. Combines evolutionary bio with developmental bio. 14. Paedomorphosis: adult’s retention of juvenile body structures. 15. Phylogeny: evolutionary history of a species or group of species. Homologies: similarities due to shared ancestry. Convergent evolution: similar adaptations favored by a common environment. Analogy: similarity due to convergent evolution. 16. Homologous; analogous 17. Taxonomy: system of naming and classifying species. Systematics: discipline of biology of classigying organisms and determining their evolutionary relations. Taxon: each taxonomic unit. Phylogenetic tree: used to show evolutionary history of species. 18. Binomal: genus and unique part for each species within the genus. 19. The first is genus, second is species. 20. In order from most inclusive to least: domain, kingdom, phylum, class, order, family, genus, species. 21. Cladistics: the method in systematics of grouping organisms into clades. Clades: a group of species that includes an ancestral species and all of its descendants. Monophyletic: a clade; a singular group of species that includes its ancestors. Phylogenetic tree: diagram used to classify groups, indicate relationships, and show patterns of descent. 22. Shared ancestral: shows up in ancestors, grouped into clades. Derived: branch from ancestors; evolved. 23. B. domestic cat 24. Parsimony: adoption of the simplest explanation for observed characteristics; allows to create phylogenetic tree. 25. False: phylogenetic trees can always be revised. 26. True: many lines of evidence support the idea that birds are a clade of reptiles. Chapter 19: 1. Evidence: anatomical, molecular, and fossil 2. Characteristics that define clades in chordates: head, vertebral column, jaws, lungs or lung derivatives, lobed fins, legs, amniotic egg, milk. 3. Craniates: chordates with a head, tetrapods: jawed vertebrates with two pairs of limbs, first vertebrates on land, amniotes: tetrapods with eggs adapted for life on land, vertebrates: extensive skull and backbone/vertebral column composed of bones called vertebrae. 4. Lancelets are thought to be the first animals to branch from the chordate lineage. 5. Hagfishes and lampreys are the most primitive craniates. 6. Hagfish: deep sea scavenger, uses slime as antipredator defense. Lamprey: parasite that penetrates the sides of fishes with its rasping tongue. (note: lampreys are vertebrates but hagfishes are not vertebrates). 7. Slime in hagfish is an antipredator defense. 8. No number 8 9. Three groups of fishes: chondrichthyans, rayfinned, and lobefinned. 10. Chondrichthyans: a. Skeleton: made of cartilage. B. use lateral line system to locate prey. C. use electrosensors/ lateral line system/sharp sense of sight and smell to detect prey, can use rays (stingrays) to sting prey and insert venom. D. examples: sharks, stingrays. 11. Rayfinned: a. Skeleton composed of bone, fins that are supported by thin flexible rays. B: operculum: protective flap that covers the gills; can breathe without swimming around. C: swim bladder is a lung derivative that helps to keep fish buoyant. D. most diverse group of vertebrates; examples: balloon fish, seahorse, flounder, trout. 12. Lobefinned: a. Key derived Characteristic: rodshaped bones in their muscular pelvic and pectoral fins. B: 3 lineages: coelacanths, lungfishes, and tetrapods. C: tetrapods (jawed vertebrates with limbs and feet that can support their weight on land) adapted to life on land. 13. Obstacles to adapting to life on land: gas exchange, water conservation, structural support, means of locomotion, adapting sensory organs that worked well in water but not on land, and reproduction. 14. The first vertebrates able to colonize the land were amphibians. 15. Amphibian examples: salamanders, frogs, caecilians. Characteristics: found in damp habitats and use moist skins to supplement their lungs for gas exchange, often have poison glands in their skins, cannot totally survive on land (need moisture). 16. Amphibians are found in damp habitats. 17. Double life: frog eggs have larval stage, where they are aquatic with gills. They then metamorphose into the adult, semiterrestrial form. Not all amphibians have a double life; some are only terrestrial and others are only aquatic. 18. Amphibians are not completely adapted to terrestrial life because they must lay their eggs in water and they cannot survive only on land. 19. Amniote examples: reptiles, birds, and mammals. Don’t need water to live or for eggs (unlike amphibians). 20. Amniotic egg’s 4 extraembryonic membranes: amnion, yolk sac, chorion, and allantois. 21. Reptile examples: lizards, snakes, turtles, crocodiles, birds, extinct dinosaurs. Characteristics: amniotic egg protected in a waterproof shell, skin covered with scales and waterproofed with the protein keratin, obtain most of their oxygen using lungs, ectothermic (absorb external heat rather than generating their own). 22. See 21 23. Ectothermic: absorb external heat rather than generating their own in order to maintain body temperature. Endothermic: generate their own body heat; regulate their own body temperature. 24. Adaptations birds have to enhance flight: forelimbs are remodeled as wings, large flight muscles provide power, also lack teeth, tail is supported by a few small vertebrae, feathers have hollow shafts, and bones have a honeycombed structure to make them strong but light (reduce weight). Also have a high rate of metabolism, are endothermic, have acute vision and fine muscle control. 25. Strong evidence indicates that birds evolved from two legged dinosaurs called theropods. 26. True: Archaeopteryx is the oldest known most primitive bird. 27. Mammals are endothermic. 28. Two distinguishing traits of mammals: hair that insulates their bodies, and mammary glands, which produce milk. 29. Three lineages of mammals: Monotremes (oldest lineage), marsupials (diverged from eutherians), and eutherians. 30. Differences between the groups of mammals: monotremes are egg laying (platupus and echidna) while marsupials and eutherians have embryos nurtured by a placenta. Marsupials have a brief gestation and give birth to tiny, embryonic offspring that complete development while attached to the mother’s nipples (typically in an external pouch) (examples: opossums, koalas, kangaroos). Eutherians: bear fully developed live young, aka placental mammals (examples: elephants, rodents, dogs, cows, and humans). 31. See 30 32. Humans are in the order Primate 33. Arboreal (treedwelling) adaptations: limber shoulder and hip joints (allows climbing and brachiation), 5 highly mobile digits on hands and feet (for grasping and manipulating food), flexible thumb, short snout and eyes set close together on front of face (enhance depth perception). 34. 3 main groups of primates: lemurs, lorises, and pottos lemurs found in madagascar and lorises and pottos found in tropical Africa and southern Asia; tarsiers southeast Asia; and anthropoids includes monkeys and apes. 35. Opposable thumb: 36. New world monkey: has a prehensile tail (can grasp things), nostrils that are wide open and farther apart. Example: golden lion tamarin. Old World Monkey: lacks a prehensile tail and has nostrils that open down (we are more similar to old world monkeys). Example: Baboon, macaque. 37. Apes: lack a tail, have relatively long arms and short legs, have relatively larger brains with respect to size, and more flexible behavior. 38. Among the apes, humans and chimpanzees are especially closely related sharing 99% of their genes.
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'