chapter 6 genetics

8. If you had a black male guinea pig and brown female guinea pig, but you didn't know which was the dominant characteristic, how would you find out the dominant color, assuming the dominant characteristic is homozygous,? A. Mate them and see what color the offspring are—that will be the dominant color. B. Mate them and see what color the offspring are—the other will be the dominant color. C. Mate them, and then mate their offspring to see what color the next generation is. D. Mate them together, and then mate their offspring to see what color the next generation is—the other color will be the dominant color.

A. Mate them and see what color the offspring are—that will be the dominant color.

9. If you were to breed a black male guinea pig to a brown female guinea pig in an attempt to determine which one was homozygous dominant and which one was homozygous recessive, how could you be certain that the guinea pigs are truly homozygous? A. The guinea pigs would be homozygous for black (or brown) coat color if each strain could be bred for many generations and only black- (or brown-) colored offspring were produced. B. If the immediate parents of the black (or brown) guinea pigs were both of that color, it proves they are homozygous. C. If a cross between the black and brown guinea pig produced three black and one brown offspring, the black guinea pig would have to be homozygous for black coat color. D. If a cross between the black and brown guinea pig produced four all black offspring, this would prove the black guinea pig was recessive.

A. The guinea pigs would be homozygous for black (or brown) coat color if each strain could be bred for many generations and only black- (or brown-) colored offspring were produced.

13. In peas, yellow is dominant over green in seeds. With which of these is it best to cross a yellow-seeded pea plant to determine whether it is homozygous or heterozygous? A. a green-seeded plant B. a heterozygous yellow-seeded plant C. a pure yellow-seeded plant D. heterozygous yellow-seeded plant or pure yellow-seeded plant

A. a green-seeded plant

1. Alternative forms of a gene that influence the same trait and are found at the same location in homologous chromosomes are called A. alleles. B. phenotypes. C. genotypes. D. codominant

A. alleles

4. Mendel's law of segregation implies that the two members of an allele pair A. are distributed to separate gametes. B. are distributed to the same gamete. C. are assorted dependently. D. are segregated pairwise

A. are distributed to separate gametes

5. Which of the following represents the physical characteristics of the individual? A. phenotype B. genotype C. alleles D. homozygous E. dominance

A. phenotype

18. If an individual with a dominant phenotype is crossed with an individual with a recessive phenotype, 4 of their 9 offspring show the recessive phenotype. What is the genotype of the dominant parent? A. AA B. Aa C. aa D. either AA or Aa

B. Aa

10. In humans, brown eyes (B) is a simple dominant trait over blue eyes (b). What is the genotype of a brown-eyed woman who has a blue-eyed child? A. bb. B. Bb. C. BB. D. BBB.

B. Bb

19. In 1940, two researchers named Weiner and Landsteiner discovered that about 85 percent of the human population sampled possessed a blood cell protein called the Rh factor. The presence of Rh factor was labeled Rh positive (Rh+) and was found to be dominant over the absence of the blood factor (Rh-). Under normal Mendelian inheritance, which statement is/are FALSE? A. Two Rh+ parents could have an Rh- child. B. Two Rh- parents could have an Rh+ child. C. An Rh- child would require that both parents be carriers of at least one Rh- allele. D. with just one pair of parents to have children where some siblings are Rh- and some are Rh+.

B. Two Rh- parents could have an Rh+ child.

2. What are alleles? A. genes for different traits, such as hair color and eye color B. alternative forms of a gene for a single trait, such as blue eyes or brown eyes C. the locations of genes on a chromosome D. recessive forms of a kind of characteristic carried by genes

B. alternative forms of a gene for a single trait, such as blue eyes or brown eyes

17. If an albino (recessive) woman is married to a man with normal coloring and they have an albino child, what was the genotype of the man? A. homozygous dominant B. heterozygous C. homozygous recessive D. incomplete dominance

B. heterozygous

3. Mendel carried out most of his research with A. livestock. B. pea plants. C. guinea pigs. D. fruit flies.

B. pea plants.

12. widow's peak (W) is dominant over straight hairline (w). If a heterozygous male marries a female with straight hairline, what %of their children can be expected to have widow's peak? A. 0% B. 25% C. 50% D. 100%

C. 50%

15. A pheasant breeder starts with two birds in the P generation, one of which is AA and the other is aa. If he takes two of the birds from the F1 generation and breeds them together, what can he expect in his F2 offspring? A. AA and Aa. B. Aa and aa. C. AA, Aa, and aa. D. AA only.

C. AA, Aa, and aa.

6. The _____ indicates the gene combination of an individual. A. phenotype B. loci C. genotype D. dominance

C. Genotype

11. The ability to roll the edges of the tongue upward in a U-shape has been considered to be an inherited ability. The standard assumption is that tongue-rolling is a dominant allele at a single gene locus. Which of the following would cast doubt on this assumption? A. Behaviors are not inherited, only structures are inherited. B. A student who cannot roll his tongue has a mother and father, both of whom can. C. A student who can roll his tongue has a mother and father, both of whom cannot. D. A student who can roll his tongue has a mother and father, both of whom cannot roll their tongues AND with very little effort the non-tongue-rollers can learn to roll their tongues

D. A student who can roll his tongue has a mother and father, both of whom cannot roll their tongues AND with very little effort the non-tongue-rollers can learn to roll their tongues

16. Some plants fail to produce chlorophyll, due to a recessive trait. If a pea plant heterozygous for this trait, self-pollinate it, and harvest the seeds, what are the phenotypes of the offspring? A. All will be green with chlorophyll since that is the dominant trait. B. All will be white and lack chlorophyll since this is self-pollinated. C. one-half will be green and one-half white since that is the distribution of the genes in the parents. D. About one-fourth will be white and three-fourths green since it is similar to a monohybrid cross.

D. About one-fourth will be white and three-fourths green since it is similar to a monohybrid cross.

7. If an organism shows a recessive phenotype, as short pea plants, its genotype can be A. either TT or Tt. B. Tt or tt. C. only TT. D. only tt.

D. Only tt

14. A woman who can roll her tongue (dominant) is married to a man who cannot. Two of their four children can roll their tongues and two cannot. If A = roll tongue and a = cannot roll tongue, then what is the genotype of the parents? A. woman Aa; man Aa B. woman AA; man aa C. woman Aa; man AA D. woman Aa; man aa

D. woman Aa; man aa