Test Bank forChapter 5: Extensions and Modifications of Basic PrinciplesMultiple Choice QuestionsTest Bank for Chapter 5: Extensions and Modifications of Basic PrinciplesMultiple Choice Questions 1. The R locus determines flower color in a new plant species. Plants that are genotype RR havered flowers, and plants that are rr have white flowers. However, Rr plants have pink flowers. What type of inheritance does this demonstrate for flower color in these plants?a. Complete dominanceb. Incomplete dominancec. Codominance d. Complementatione. Lethal allelesAnswer: bSection 5.1Comprehension2. Interactions among the human ABO blood group alleles involve _______ and ________.a. co-dominance; complete dominanceb. codominance; incomplete dominancec. complete dominance; incomplete dominanced. epistasis; complementatione. continuous variation; environmental variationAnswer: aSection 5.1Comprehension3. In the endangered African watchamakallit, the offspring of a true-breeding black parent and atrue-breeding white parent are all gray. When the gray offspring are crossed among themselves, their offspring occur in a ratio of 1 black:2 gray:1 white. Upon close examinationof the coats, each hair of a gray animal is gray. What is the mode of inheritance?a. One gene pair with black dominant to whiteb. One gene pair with codominancec. One gene pair with incomplete dominanced. Two gene pairs with recessive epistasise. Two gene pairs with duplicate genesAnswer: cSection 5.1Comprehension4. Suppose that extra fingers and toes are caused by a recessive trait, but it appears in only 60% of homozygous recessive individuals. Two heterozygotes conceive a child. What is the probability that this child will have extra fingers and toes?a. 0.05b. 0.10c. 0.15d. 0.25e. 0.33Answer: cSection 5.1Comprehension5. Polydactyly is the condition of having extra fingers or toes. Some polydactylous persons possess extra fingers or toes that are fully functional, whereas others possess only a small tag of extra skin. This is an example ofa. variable expressivity.b. complete dominance.c. independent assortment.d. complementation.e. cytoplasmic inheritance.Answer: aSection 5.1Comprehension6. Achondroplasia is a common cause of dwarfism in humans. All individuals with achondroplasia are thought to be heterozygous at the locus that controls this trait. When two individuals with achondroplasia mate, the offspring occur in a ratio of 2 achondroplasia:1 normal. What is the most likely explanation for these observations?a. Achondroplasia is incompletely dominant to the normal condition.b. Achondroplasia is codominant to the normal condition.c. The allele that causes achondroplasia is a dominant lethal allele.d. The allele that causes achondroplasia is a recessive lethal allele.e. The allele that causes achondroplasia is a late-onset lethal allele.Answer: dSection 5.1Comprehension7. Crossing two yellow mice results in 2/3 yellow offspring and 1/3 nonyellow offspring. What percentage of offspring would you expect to be nonyellow if you crossed two nonyellow mice?a. 25%b. 33%c. 66%d. 75%e. 100%Answer: eSection 5.1Comprehension8. In humans, blood types A and B are codominant to each other and each is dominant to O. What blood types are possible among the offspring of a couple of blood types AB and A?a. A, B, AB, and Ob. A, B, and AB onlyc. A and B onlyd. A, B, and O onlye. A and AB onlyAnswer: bSection 5.1Comprehension9. A mother of blood type A gives birth to a child with blood type O. Which of the following could NOT be the blood type of the father?a. Ab. Bc. Od. ABe. Any of the above is a possible blood type of the father.Answer: dSection 5.1Comprehension10. You are studying body color in an African spider and have found that it is controlled by a single gene with four alleles: B (brown), br (red), bg (green), and by (yellow). B is dominant toall the other alleles, and by is recessive to all the other alleles. The bg allele is dominant to by but recessive to br. You cross a pure-breeding brown spider with a pure-breeding green spider. Predict the genotype of the progeny.a. B/bgb. Br/bgc. br/byd. by/bge. B/byAnswer: aSection 5.1Application11. You are studying body color in an African spider and have found that it is controlled by a single gene with four alleles: B (brown), br (red), bg (green), and by (yellow). B is dominant toall the other alleles, and by is recessive to all the other alleles. The bg allele is dominant to by but recessive to br. You cross a pure-breeding brown spider with a pure-breeding green spider. Predict the phenotype of the progeny.a. Half brown, half greenb. Three-fourths brown, one-fourth greenc. All brownd. All greene. All yellowAnswer: cSection 5.1Application12. In rabbits, an allelic series helps to determine coat color: C (full color), cch (chinchilla; gray color), ch (Himalayan; white with black extremities), and c (albino; all white). The C allele is dominant to all others, cch is dominant to ch and c, ch is dominant to c, and c is recessive to all the other alleles. This dominance hierarchy can be summarized as C > cch > ch > c. Indicate the phenotypic ratios expected if rabbits with the cross Ccch  Cch.a.1 full color:1 chinchillab.1 full color:1 Himalayanc.1 chinchilla:1 Himalayand.3 full color:1 chinchillae.2 full color:1 Himalayan:1 albinoAnswer: dSection 5.1Application13. In rabbits, an allelic series helps to determine coat color: C (full color), cch (chinchilla; gray color), ch (Himalayan; white with black extremities), and c (albino; all white). The C allele is dominant to all others, cch is dominant to ch and c, ch is dominant to c, and c is recessive to all the other alleles. This dominance hierarchy can be summarized as C > cch > ch > c. Indicate the phenotypic ratios expected if rabbits with the cross Cch  chc.a.1 full color:1 chinchillab.1 full color:1 Himalayanc.1 chinchilla:1 Himalayand.3 full color:1 chinchillae.2 full color:1 Himalayan:1 albinoAnswer: bSection 5.1Application14. In rabbits, an allelic series helps to determine coat color: C (full color), cch (chinchilla; gray color), ch (Himalayan; white with black extremities), and c (albino; all white). The C allele is dominant to all others, cch is dominant to ch and c, ch is dominant to c, and c is recessive to all the other alleles. This dominance hierarchy can be summarized as C > cch > ch > c. Indicate the phenotypic ratios expected if rabbits with the cross Cch  cc.a.1 full color:1 chinchillab.1 full color:1