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Chapter 23 BIOOOO
Chapter 24 BIOOOO
| Question | Answer |
|---|---|
| Natural Selection acts on individuals, only _______ evolve | Populations |
| Is a change in allele frequencies in a population over generations | Microevolution |
| Three Mechanisms that cause allele frequency change | Natural Selection, Genetic drift, Gene Flow |
| Only Natural Selection causes ______ _____ | adaptive evolution |
| _______ in heritable traits is a prerequiste for evolution | Variation |
| Genetic Variation among individuals is caused by ____________ | differences in genes or other DNA segments |
| Phenotype is the product of | inherited genotype and environmental influences |
| Natural Selection can only act on | variation w/ a genetic component |
| _____ can be classified on a either or basis | Discrete Characters |
| ________ vary along a continuum within a population | Quantative Characters |
| ____ measures the average percent of loci that are heterozygous in a population | average heterzygostity |
| _____ is measured by comparing the DNA sequences of pairs on individuals | Nucleotide Variability |
| differences b/w gene pools of seperate populations | geographic variation |
| Some examples of geographic variation occur as a______, which is a graded change in trait along a geographic axis | Cline |
| is a change n nucleotide sequence of DNA | mutation |
| Only mutations in cells that produce ____ can be passed to offspring | gametes |
| ____ is a change in one change in one base in a gene | Point mutation |
| Chromosomal Mutations that delete, disrupt or rearrange many loci are typically ... | harmful |
| Duplication of small pieces of DNA increases _________ | genome size and is usually less harmful |
| Duplicated genes can take on ____ | new functions by further mutations |
| Mutation rates are _____ in animal and plants | low |
| Mutation rates are often lower in _____ and higher in ______ | prokaryotes; viruses |
| is a localized group of individuals capable of interbreeding and producing fertile offspring | population |
| consists of all the alleles for all loci in a population | gene pools |
| A _____ is fixed if all individuals in a population are homozygous for the same allele | Locus |
| The Hardy Weinberg principle describes | a population that is not evolving |
| _______ states that frequencies of alleles and genotypes in a population remain constant from generation to generation | Hardy-Weinberg Principle |
| 5 conditions for nonevolving populations | No mutations, random mating, no natural selection, extremely large population size, no gene flow |
| describes how allele frequencies fluctuate unpredictably from one generation to the next | Genetic Drift |
| Genetic Drift tends to | reduce genetic variation through losses of alleles |
| ______ occurs when a few individuals become isolated from a larger population; their allele frequencies might be different b/c of this | founder effect |
| _____ is a sudden reduction in population size due to a change in the environment | bottleneck effect |
| Genetic drift is significant in _________ | small populations |
| Genetic Drift cause allele frequencies... | to change at random |
| Genetic drift can lead to a loss of... | gentetic variation within populations |
| Genetic drift can cause______ | harmful alleles to become fixed |
| consists of the movement of alleles among populations | Gene Flow |
| Gene flow tends to ______ among populations over time | reduce variation |
| Gene can _____ or ____ the fitness of a population | decrease or increase |
| Evolution by natural selection involves both _____ and ______ | change and sorting |
| New genetic variations arise by ______; Beneficial alleles are "_____" and favored by natural selection | chance; sorted |
| Only natural selection consistently results in ________ | adaptive evolution |
| is generally more subtle and depends on many factors | Reproductive success |
| is the contribution an individual makes to the gene pool of the next generation, relative to the contributions of other individuals | Relative Fitness |
| favors individuals at one end of the phenotypic range | Directional Selection |
| favors individuals at both extremes of the phenotypic range | Disruptive Selection |
| favors intermediate variants and acts against extreme phenotypes | Stabilizing Selection |
| ______increases the frequencies of alleles that enhance survival and reproduction | Natural Selection |
| Adaptive evolution occurs as the match between an _____ and its _____ increases | organisms; environment |
| Because the environment can change, adaptive evolution is a ___________ | continuous process |
| is a natural selection for mating success | Sexual Selection |
| marked differences between the sexes in secondary sexual characteristics | Sexual Dimorphism |
| is competition among individuals of one sex (often males) for mates of opposite sex | Intrasexual Selection |
| often called mae choice, occurs when individuals of one sex (usually females) are choosy in selecting their mates | Intersexual Selection |
| Male Showiness sue to mate chose can increase a male's chances of attracting a female, while decreasing his chances of survival | READ |
| is genetic variation that does not confer a selective advantage or disadvantage | Neutral Variation |
| _____ maintains genetic variation in the form of hidden recessive alleles | Diploidy |
| _____ can carry recessive alleles that are hidden from the effects of selection | Heterozygotes |
| _____ occurs when natural selection maintains stable frequencies of two or more phenotypic forms in a population | Balancing Selection |
| balancing Selection includes: | Heterozygote advantage and Frequency-dependent selection |
| ________ occurs when heterozygotes have a higher fitness than do both homozygotes | Heterozygote advantage |
| ____ the fitness of a phenotype declines if it becomes too common in the population | Frequency Dependent Selection |
| Selection can favor ____ | whichever phenotype is less common in a population |
| Why Natural Selection Cannot Fashion Perfect Organisms | 1. Selection can act only on existing variations 2. Evolution is limited by historical constraints 3. Adaptions are often compromises 4. Chance, natural selection, and the environment interact |
Created by:
uali1994