Ch. 16 Questions

Which of the following would change the allele frequencies of a population? a. DNA is stable from generation to generation and doesn't change, so allele frequencies don't change b. Tall people in a population preferentially marry other tall people and do not marry people who are short or average height c. A population on an island remains isolated and no one leaves or moves onto the island d. All of these are correct

B

Which of the following is not involved in natural selection? a. there is always competition for resources b. organisms differ in reproductive success c. there are inheritable variations in populations d. the desired traits are chosen by a breeder

D

A random alteration in the sequence of DNA nucleotides that provides a new variant allele is a. gene mutation b. polymorphism c. gene frequency d. disruption

a

In some bird species, the female chooses a mate that is most similar to her in size. This supports a) the good genes hypothesis b) the runaway hypothesis c) the sexual dimorphism hypothesis d) all of these could be true e) none of the above

a

Which of the following conditions is necessary to maintain the Hardy-Weinberg equilibrium (meaning there is no change in allele frequency) a. Random mating b. Mutation c. sexual selection d. gene flow e. genetic drift

a

You see 2 birds of the same species, one male and one female. The male is ornate and larger in size. This species would be considered sexually simorphic a. true b. false

a

Following genetic drift, a) genotype and allele frequencies would not change b) Genotype and allele frequencies would change c) adaption would occur d) the population would have more phenotypic variation but less genotypic variation

b

When a population is small, there is a greater chance of a) gene flow b) genetic drift c) natural selection d) mutations e) sexual selection

b

Which genotype is characteristic of the heterozygote advantage? a) HH b) Hh c) hh d) ta e) HT

b

Which of the following is true about genetic drift? a. it is more likely to occur in a large population than in a small population b. it may lead to an allele's becoming fixed in a population when its alternate allele is lost from the population c. it increases the number of heterozygotes in a population d. it increases the frequency of rare alleles in a population

b

A human population has a higher than usual percentage of individuals with a genetic disorder. The most likely explanation is a) mutations & gene flow b) mutations & natural selection c) nonrandom mating & founder effect d) nonrandom mating & gene flow e) All of these are correct

c

A red deer harem master typically dies earlier than other males because a) he will likely be expelled from the herd and can't survive alone b) he will be more prone to disease because he interacts with so many animals c) he needs more food than other males d) he is apt to place himself between a predator and the herd to protect the herd d) he inherited the genetics for a shorter lifespand

c

All the members of a single species that occupy a particular area at the same time are known as a a. subspecies b. gene pool c. population d. group e. sub-population

c

Assuming a Hardy-Weinberg Equilibrium, 21% of a population is homozygous dominant, 50% is heterozygous, and 29% is homozygous recessive. What percentage of the next generation is predicted to be homozygous recessive? a) 21% b) 59% c) 29% d) 42% e) 58%

c

The continued occurrence of sickle-cell disease with malaria in parts of Africa is due to a) continual mutation b) gene flow between populations c) relative fitness of the heterozygote d) disruptive selection e) protozoan resistance to DDT

c

The offspring of a better-adapted individuals are expected to make up a larger proportion of the next generation. The most likely explanation is a) mutations & nonrandom mating b) gene flow & genetic drift c) mutations & natural selection d) mutations & genetic drift

c

What is the term used to describe the changes in allele frequencies of a population over generations? a. genetic drift b. founder effect c. microevolution d. direction selection

c

Which of the following is an example of stabilizing selection? a) over time, Equus developed strength, intelligence, speed and durable grinding teeth b) British land snails mainly have 2 different phenotypes c) Swiss starlings usually lay 4 or 5 eggs, thereby increasing their chances of more offspring d) Drug resistance increases with each generation; the resistant bacteria survive, and the nonresistant get killed off e) all of the above

c

Variation within a population are maintained by? a. mutation b. genetic recombination due to fertilization c. gene flow d. all of these are correct

d

Which statement is NOT true about natural selection a. directional selection occurs when one extreme phenotype is favored over another different extreme phenotype b. Stabilizing selection favors an intermediate phenotype over either of the extreme phenotypes c. Disruptive selection favors both of the extreme phenotypes over the intermediate phenotype d. Direction selection leads to improved selection in a stable environment e. Disruptive selection leads to polymorphism, favoring different forms of the same species

d

One way for disruptive selection to occur is if a) the population contains diversity b) the environment contains diversity c) pollution is present d) natural selection occurs e) all of the above

e

Which of the following applies to the Hardy-Weinberg expression: p^2 +2pq + q^2? a) knowing either p^2 or q^2, you can calculate all the other frequencies b) it applies to Mendelian traits that are controlled by one pair of alleles c) 2pq = heterozygous individuals d) It can be used to determine the genotype & allele frequencies of the previous & the next generations d) all of the above

e

Which of the following cannot occur if a population is to maintain an equilibrium of allele frequencies? a) People leave on country and relocate in another b) a disease wipes out the majority of a herd of deer c) members of an Indian tribe allow only the two tallest people in the tribe to marry each spring d) Large black rats are the preferred males in a population of rats e) all of the above

e