生态学英文题库

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CHAPTER 7 Evolution and Adaptation

The process of evolution depends on genetic variation.

MULTIPLE CHOICE

1.Topic: The process of evolution depends on genetic variation.

Level: easy

Different forms of a particular gene are known as

a. chromosomes.

b. alleles.

c. polygenic.

d. pleiotropic.

Answer: b

2.Topic: The process of evolution depends on genetic variation.

Level: easy

A trait that is determined by multiple genes is referred to as

a. polygenic.

b. pleiotropi

c.

c. homozygous.

d. heterozygous.

Answer: a

3.Topic: The process of evolution depends on genetic variation.

Level: medium

Chickens with the dominant allele at the frizzle gene produce curly feathers, have very high body temperature, and lay few eggs.This is an example of

a. polygenic traits.

b. pleiotropy.

c. epistasis.

d. random assortment.

Answer: b

4. Topic: The process of evolution depends on genetic variation.

Level: medium

Two of the genes that affect coat color in horses are the extension gene and the cream dilution gene. The dominant E allele at the extension gene generates black coats, while the recessive e allele produces red coats.The coat color caused by the extension gene is not altered if the horse is a homozygote for the C allele at the cream dilution gene.However, if the horse is a homozygote for the C Cr allele at the cream dilution gene, it will have a white coat regardless of the extension genotype.This interaction between the extension and the cream dilution gene is an example of

a. pleiotropy.

b. epistasis.

c. codominance.

d. random assortment.

Answer: b

5. Topic: The process of evolution depends on genetic variation.

Level: difficult

Which of the following types of allele would we expect to have the lowest frequency in a population?

a. beneficial recessive allele

b. beneficial dominant allele

c. harmful recessive allele

d. harmful dominant allele

Answer: d

6. Topic: The process of evolution depends on genetic variation.

Level: medium

Consider a gene that affects fur color in mice.This gene has two alleles, A and a.If AA mice have white fur, Aa mice have gray fur, and aa mice have black fur, how would we describe the effect of these alleles?

a. A is dominant and a is recessive.

b. A is recessive and a is dominant.

c. A and a are codominant.

d. A and a are epistatic.

Answer: c

7. Topic:The process of evolution depends on genetic variation.

Level: medium

Consider a gene that affects number of seeds in a plant.This gene has two alleles, G and g.If GG plants produce 50 seeds, Gg plants produce 50 seeds, and gg plants produce 25 seeds, how would we describe the effect of these alleles?

a. G is dominant and g is recessive.

b. G is recessive and g is dominant.

c. G and g are codominant.

d. G and g are polygenic.

Answer: a

8. Topic:The process of evolution depends on genetic variation.

Level: easy

What term refers to the alleles of all of the genes of every individual in a population?

a. polygenic

b. heterozygous

c. gene pool

d. random assortment

Answer: c

9. Topic:The process of evolution depends on genetic variation.

Level: easy

What process creates new alleles in a population?

a. random assortment