Exam 2 review-Ch. 9, 10.1-10.5, 11.1-11.3, 14.1-14.3, 15, 16, 17 PDF

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Ch. 9, 10.1-10.5, 11.1-11.3, 14.1-14.3, 15, 16, 17...

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BSC2005 General Biology Unit 2 exam review topics Ch. 9, 10.1-10.5, 11.1-11.3, 14.1-14.3, 15, 16, 17 Chapter 9: The Cell Cycle •

What is mitosis? Why do cells undergo mitosis? Describe the daughter cells that result from mitosis. •

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Mitosis is the nuclear division. It permits growth and repair. Daughter cells are genetically identical. Daughter chromosomes are distributed by the mitotic spindle to 2 daughter nuclei.

What is the difference between asexual and sexual reproduction? Why and/or under what conditions is one type more advantageous than the other? •

Asexual: The offspring are clones — genetically identical to the parent. •

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Gametes formed by meiosis and they are haploid.

Binary fission: Splitting of a parent cell into two genetically identical daughter cells. Two replicated chromosomes are distributed to two daughter cells. Asexual.

Cell cycle: An orderly set of stages from the first division of a eukaryotic cell. Interphase and mitotic stage.

Programed cell death. Keep the number of cells in the body at an appropriate level.

Gamete: Germ cell that can form a zygote. Egg and sperm. Body cells have 46 chromosome(haploid, found in all cells of individuals), gametes have 23 chromosome (diploid).

What is cytokinesis? How does it differ from mitosis? •

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Results in offspring with genetic variation.

Define gamete. Know the number of chromosomes in gametes and regular body (somatic) cells and whether they are haploid or diploid. •

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Is advantageous when the environment is stable.

What is apoptosis and why is it important? •

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A predator or disease could more easily destroy the entire population.

What are the major phases of the cell cycle? •

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More difficult to adapt to a changing environment.

How do prokaryotes reproduce? Is this asexual or sexual reproduction? •

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Allows for quick increase in the population.

Sexual: Must have 2 parents. •

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Any genetic variations are due to mutations.

Division of cytoplasm. Mitosis is the process in which the nucleus of a eukaryotic cell divides. During this process, sister chromatids separate from each other and move to opposite poles of the cell. Cytokinesis is the final stage of cell division, during which the cytoplasm splits into two and two daughter cells form.

What is cancer? What’s the difference between benign and malignant tumors? •

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Cancer: A cellular growth disorder that occurs when cells divide uncontrollably. Benign tumors are not cancerous, Encapsulated. Do not invade neighboring tissue or spread. 1

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Malignant tumors are cancerous, Not encapsulated. Metastasis. Result from mutation of genes regulating the cell cycle.

Chapter 10: Meiosis •

What is meiosis? What are the two main processes involved in the sexual reproduction cycle (in many plants, too, in alternation of generations) that combines and changes the number of chromosomes (i.e., whether cells are haploid (n) or diploid (2n))? •

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Crossing over: An exchange of genetic material between non sister chromatids(homologous chromosomes) of a bivalent during meiosis I. Occurs during prophase I. Independent assortment: The homologous chromosome pairs separate independently (randomly). Occurs during metaphase I.

Mitosis: Results in 2 daughter cells and 46 chromosomes. Meiosis: Results in 4 daughter cells and 23 chromosomes.

Homologous chromosomes: Two pieces of DNA within a diploid organism which carry the same genes, one from each parental source. Because they contain genes for the same traits in the same order in the same location. (However, the DNA sequences of alleles has a slight difference that makes them similar instead of identical.) They have the same length, size, shape, genetic material. Centromeres in the same place. Anaphase I.

What are sister chromatids? When can they split and why do they split into single chromatids? What type of cells have chromosomes with only one chromatid? •

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Mutation introduce variation in asexually reproducing organisms.

What are homologous chromosomes. Why are they homologous? What is the same between them? genes? alleles? Size? Other characteristics? When do homologous chromosomes split? •

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Mutation, Crossing over, independent assortment.

Compare mitosis to meiosis. How many daughter cells and number of chromosomes result after each? •

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Essential for a species to evolve and adapt in a changing environment.

When does crossing over occur (and what is it)? When does independent assortment occur (and what is it)? •

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Meiosis and fertilization.

Explain the importance of genetic variation and the 3 principle ways it is produced in organisms that reproduce sexually. How is variation primarily introduced in asexually reproducing organisms? •

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Meiosis: The type of nuclear division that reduces the chromosome number from diploid to haploid.

Sister chromatids: Two identical copies of the same chromosome formed by DNA replication, attached to each other by a structure called the centromere. Meiosis II. Because they need to form 4 daughter cells that are haploids. Daughter cell from meiosis.

What is a chromosome? What is a gene? What is an allele? •

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Chromosome: A threadlike structure of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes. Gene: Basic physical and function unit of heredity, made of DNA. Alleles: Forms of the same gene with small differences in their sequence of DNA bases.

Chapter 11: Mendelian genetics •

What are Mendel’s laws of Segregation and of Independent assortment? When during meiosis are each of these laws supported? 2

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Distinguish between phenotype and genotype, dominant and recessive, homozygous and heterozygous. •

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Phenotype: The physical appearance if an individual (tall/short). Genotype: The 2 alleles an individual receives at fertilization. Dominant: The capital letter, masks the expression of the recessive, the lowercase. Homozygous: Two identical alleles. (TT/tt) Heterozygous: Two different alleles. (Tt)

Define P, F1, and F2 generations. Solve and interpret a one trait (monohybrid) cross using a Punnett square; Define a dihybrid cross. •

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Law of Segregation (metaphase II): Each individual has a pair of alleles for each trait, one from mom/ dad. Alleles are on different chromosomes. Alleles segregate independently among the offspring during gamete formation. Each gamete contains only one copy of a particular allele. Law of Independent Assortment (Metaphase I in meiosis I): The pair of factors for one trait segregate independently of the factors for other traits. All possible combinations of factors can occur in the gametes.

P: Parental generation. F1: First generation, they are all hybrids that show the dominant trait. F2 : Second generation. Monohybrid: Cross between parents that differ in only one trait. Punnett square: Table listing all possible genotypes resulting from a cross. Dihybrid: Cross between parents that differ in 2 traits.

? What phenotype and genotype ratios result from a true monohybrid cross? Be able to identify these ratios for crosses of any given genotypes (for monohybrid cross).

Chapter 14: Biotechnology and Genomics •

Describe uses of genetically modified organisms. •

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Define and distinguish among the terms (and examples of) transgenic organisms, genetically modified organisms (GMO), and organisms with recombinant DNA. •

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Transgenic: An example of a GMO that has had a gene from another species inserted into its genome. Transgenic bacteria. GMO: Whose genome has been modified in some way. Plants. Recombinant DNA: Contains DNA from 2 or more different sources.

Define and identify examples of the process of gene therapy. •

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Increased crop yields, reduced costs for fodder drug, cloning, produce biotechnology products.

Gene therapy: A therapy that gives patients healthy genes to make up for a faulty gene. Ex vivo: The gene is inserted into cells that have been removed and then returned to the body. In vivo: Gene is delivered directly into the body.

What is the function of DNA ligase and restriction enzymes? •

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These are the 2 enzymes that are needed to introduce foreign DNA into vector DNA. DNA ligase: Seals DNA into an opening created by the restriction enzyme. Restriction enzyme: Cuts DNA during production of recombinant DNA.

Chapter 15: Darwin and Evolution •

What is evolution? What is Darwin’s theory of Evolution? •

Evolution: Genetic change occurs in a species over time. 3

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What evidence supports evolution as a fact? (e.g., Biogeographic, anatomical, fossils, and others) •

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Fossils: remains and traces of past life or any other direct evidence of past life such as trails, footprints, or preserved droppings. Record the history of life from the past. Sometimes can show descent from an ancestor. Transitional fossils: Common ancestor for 2 different groups of organisms. Biogeographical: A different mix of plants and animals would be expected whenever geography separates continents, islands, seas. Anatomical: Homologous structures, anatomically similar because they are inherited from a common ancestor. Biochemical

What is an adaptation? How are adaptations important as part of Darwin’s theory of Evolution? •

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Darwin’s theory of evolution: Individuals have variation that is heritable; organisms compete for resources; differential reproductive success; adaptation to environmental change. (All species of organisms arise and develop through the natural selection of small, inherited variations that increase the individual's ability to compete, survive, and reproduce.)

Adaptation: Change that helps a species become more suited to its environment. It’s the product of natural selection.

Where did Darwin make many of his most important observations (and of which organisms) that led him to develop his theory of evolution? •

Galapagos Islands. Finches.

Chapter 16: How populations evolve •

What is a population, gene, and allele? •

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Microevolution: Change in gene (allele) frequencies between population of a species over time. (If allele frequencies don’t change, no microevolution has occurred.) Mutation, selection (natural and artificial), gene flow and genetic drift. Macroevolution happens on a larger scale. Macroevolution is the accumulation of mircoevolutions.

Gene pool: Total of the alleles of all the individuals in a population. “p”: Frequency of A allele. “q”: Frequency of a allele P+ q = 1

What is Hardy-Weinberg equilibrium? What are assumptions of H-W equilibrium? •

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Allele: One or more alternative forms of a gene that arise by mutation and are found at the same place on the chromosome.

Define gene pool. Understand how to calculate allele and genotype frequencies and identify whether they have changed if given a population gene pool at 2 different times. •

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Gene: Unit of heredity; a sequence of nucleotides; is on a chromosome.

What is microevolution? What is necessary for microevolution to take place? What’s the difference between microevolution and macroevolution? •

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Population: A group of organisms of a single species living together in the same geographic area.

Hardy-Weinberg equilibrium: A stable, non-evolving state. Assumes: No mutation; no gene flow; random mating; no genetic drift. No selection.

List and understand the 5 potential causes of microevolution and examples of each. This will include a review of terms like Genetic drift (and the 2 types discussed), non-random mating (assortive, disassortive mating, and examples of sexual selection), gene flow, and natural selection. 4

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1. Genetic mutation: A change in nucleotide sequences. Very unlikely will happen. Can change a populations gene pool. Occur randomly. Some may be more adaptive than others. 2. Gene flow: The movement of alleles between populations. Occurs when plants or animals migrate. Without gene flow, gene pools become more different, and reproductive isolation occurs. 3. Genetic drift: Changes in the allele frequencies of a population due to change rather than selection by the environment. Stronger effect in small populations. Bottleneck effect: The loss of genetic diversity is due to natural disasters, diseases, overhunting/ over-harvesting or habitat loss. Founder effect: Loss of genetic variation due to a few individuals break away from a large population to found a new population. 4. Nonrandom mating: •

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Assortative mating: Selecting mates with the same phenotype with respect to a certain characteristic. Increases the frequency of homozygotes. Disasortive mating (generally random): Selecting others of a different genotype.

Sexual selection: Nonrandom mating & natural selection. Adaptive changes in males and females lead to an increased ability to secure a mate. 5. Natural selection: The adaptation of a population to the biotic and abiotic environment. Favors the most adaptive to the environment. Changes allele frequencies. Improve fitness of the population. •

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What is natural selection and what is necessary for natural selection to take place? •

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Reproduction, heredity, variation in fitness or organisms, variation in individual characters among members of the population

Define and distinguish among stabilizing, directional, and disruptive selection (all types of natural selection). Understand examples of each. •

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Stabilizing: An intermediate phenotype is the most adaptive for the given environmental conditions. Directional: Extreme phenotype is favored. Disruptive: 2 or more extreme phenotypes are favored over the intermediate phenotype.

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Chapter 17: Speciation and Macroevolution •

What is macroevolution? •

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What is speciation? •

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Splitting of one species into two or more.

Define and distinguish among the 4 species concepts discussed. •

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Evolution at the species or higher level of classification. Best observed within the fossil record. Involves speciation.

1. Morphological: Based on analysis of physical characteristics to distinguish one species from another. 2. Evolutionary: Relies on identification of certain morphological traits. 3. Phylogenetic: Used to identify species based on a common ancestor. 4. Biological: Relies primarily on reproductive isolation to identify different species.

What are examples of prezygotic vs. postzygotic (e.g., sterile hybrids) isolating mechanisms? •

Prezygotic: Prevent mating attempts or make it unlikely that fertilization will be successful if mating occurs. 1. Habitat: 2 species occupy different habitats. •

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2. Temporal: Several related species in the same locale but reproduce at different time period. 3. Behavioral: Courtship patterns allowing male and female to recognize one another. 5

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4. Mechanical: Incompatible animal genitalia or plant floral structures. 5. Gamete: Gametes do not fuse.

Postzygotic: Operate after the formation of zygote. Prevent hybrid offspring from developing and reproducing. Inviability: Hybrid zygote not viables. •

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Define and distinguish between allopatric vs. sympatric speciation. Recognize examples of each. •

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Sterility: Develops but unable to produce offspring.

Allopatric: Population departed by a geographic or other type of physics barrier. (Ex: Ensatina ring species) Sympatric: One population develops into two or more reproductively isolated groups in the absence of geographic barrier. (Ex: Nicaragua fishes)

Define convergent evolution, analogous traits, and homologous traits. Recognize examples of each. •

Convergent evolution: Similar biological trait evolves in 2 unrelated species as a result of exposure to similar environments. Analogous: Similar function, different anatomy and ancestry. (Bird wing & bat wings) •

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Homologous: Similar traits in different types of organism because they shared a common ancestor. (Wings of butterflies and moths, both evolved from Lepidoptera)

Distinguish between the gradualistic vs. punctuated equilibrium models of macroevolution. •

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Gradualistic: Evolution at the species level occurs gradually over time. Punctuated: Species can appear quite suddenly.

Additional word bank to review (in addition to words highlighted in RED) in bulleted lists above: fertilization

hybrid:

Founder effect

1. A hybrid is the offspring resulting from combining the qualities of two organisms of different breeds, varieties, species or genera through sexual reproduction. Gregor Mendel:

Gene cloning:

1. Austrian monk and teacher

1. DNA cloning to produce many identical copies of the same gene.

2. Had no knowledge of cells or chromosomes

Bottleneck effect

3. Did not have a microscope 4. Experiments on the inheritance of simple traits in the garden pea disproved the blending hypothesis eukaryote

Gel electrophoresis:

Florida panther

1. Process that separates DNA fragments according to their size

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Prokaryote

Interphase

genomics:

t-shirt smell experiment: 1995

The study of genomes

1. A group of female college students smelled t-shirts that had been worn by male students for two nights, without deodorant, cologne or scented soaps. Overwhelmingly, the women preferred the odors of men with dissimilar MHCs to their own.

genome:

Female choice

1. All genetic material of an organism Mitotic stage

Charles Darwin

Male competition

Cell cycle checkpoint

biogeography:

Se...