Name Class Date
Introduction to Genetics Chapter Test A
Multiple Choice
Write the letter that best answers the question or completes the statement on the line provided.
_____ 1. If a pea plant has a recessive allele for green peas, it will produce
a. green peas if it also has a dominant allele for yellow peas.
b. both green peas and yellow peas if it also has a dominant allele for yellow peas.
c. green peas if it does not also have a dominant allele for yellow peas.
d. yellow peas if it does not also have a dominant allele for green peas.
_____ 2. If a pea plant’s alleles for height are tt, what is true of its parents?
a. Both parents were tall.
b. Both parents were short.
c. Both parents contributed a recessive allele.
d. Both parents contributed a dominant allele.
_____ 3. In the Punnett square shown in Figure 11–1, which of the following is true about the offspring resulting from the cross?
a. About half will be short.
b. All will be short.
c. About three fourths will to be tall.
d. All will be tall.
_____ 4. How many different allele combinations would be found in the gametes produced by a pea plant whose genotype was RrYY?
a. 2 c. 8
b. 4 d. 16
_____ 5. Use Figure 11–2 to answer the following question. If a pea plant that is heterozygous for round, yellow peas (RrYy) is crossed with a pea plant that is homozygous for round peas but heterozygous for yellow peas (RRYy), how many different phenotypes are their offspring expected to show
a. 2
b. 4
c. 8
d. 16
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_____ 6. A male and female bison that are both heterozygous for normal skin pigmentation (Aa) produce an albino offspring (aa). Which of Mendel’s principles applies?
a. dominance only c. dominance and segregation
b. independent assortment only d. segregation only
_____ 7. When one allele is not completely dominant over another, this is an example of
a. multiple alleles. c. polygenic inheritance.
b. incomplete dominance. d. multiple genes.
_____ 8. A cross of a black chicken (BB) with a white chicken (WW) produces all speckled off spring (BBWW). This type of inheritance is known as
a. incomplete dominance. c. codominance.
b. polygenic inheritance. d. multiple alleles.
_____ 9. Variation in human skin color is an example of
a. incomplete dominance. c. polygenic traits.
b. codominance. d. multiple alleles.
_____ 10. Which of the following shows that the environment can affect genetic traits?
a. Oak trees get taller as they grow.
b. Hydrangea flower color varies with soil pH.
c. Dandelion plants are self-pollinating.
d. Pinion trees bear cones every other year.
_____ 11. Gametes have
a. homologous chromosomes.
b. twice the number of chromosomes found in body cells.
c. two sets of chromosomes.
d. one allele for each gene.
_____ 12. Chromosomes form tetrads during
a. prophase I of meiosis. c. interphase.
b. metaphase I of meiosis. d. anaphase II of meiosis.
_____ 13. Which of the following assort independently?
a. chromosomes c. multiple alleles
b. linked genes d. codominant alleles
_____ 14. The farther apart two genes are located on a chromosome, the
a. less likely they are to be inherited together.
b. more likely they are to be linked.
c. less likely they are to assort independently.
d. less likely they are to be separated by crossing-over.
_____ 15. What is formed at the end of meiosis?
a. two genetically identical cells
b. four genetically different cells
c. four genetically identical cells
d. two genetically different cells
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Completion
Complete each statement on the line provided.
16. Due to the process of segregation, alleles separate during the production of
.
17. If pea plants that are homozygous for round, yellow seeds (RRYY) were crossed with pea plants that are heterozygous for round, yellow seeds (RrYy), the expected phenotype(s) of the offspring would be .
18. The reddish-brown pigment that gives color to a fruit-fly’s eye is controlled by three genes, so a fruit fly’s eye color is a .
Short Answer
In complete sentences, write the answers to the questions on the lines provided.
19. What is the difference between segregation and independent assortment?
20. A tall pea plant with yellow seeds is heterozygous for height and seed color (TtYy). This plant is crossed with a pea plant heterozygous for height but homozygous recessive for seed color (Ttyy). If 80 offspring are produced, how many are expected to be tall and have yellow seeds?
21. What is the probability that a cross between parents who are both homozygous recessive for trait will have off spring that are homozygous recessive for that trait?
22. Arctic foxes have blue-gray fur in summer and change to white fur in winter. What would be one way to test whether this change is influenced by cooling seasonal temperatures?
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