BIO 160 - CHAPTER 9

Which of the following terms refers to a situation where a single phenotypic character is determined by the additive effects of two or more genes? a. pleiotropy b. incomplete dominance c. codominance d. polygenic inheritance

Two mice are crossed. Matings are carried out between the offspring of these mice to produce "grandchildren" of the original mated pair. In the standard terminology of genetics, the "grandchildren" are the _____. a. P generation b. F1 generation c. F2 generation d. F3 generation

Which of the following statements regarding genotypes and phenotypes is false? a. Alleles are alternate forms of a gene. b. An organism with two different alleles for a single trait is said to be homozygous for that trait. c. The expressed physical traits of an organism are called its phenotype. d. The genetic makeup of an organism constitutes its genotype.

Assuming that the probability of having a female child is 50% and the probability of having a male child is also 50%, what is the probability that a couple's first-born child will be female and that their second-born child will be male? a. 75% b. 50% c. 25% d. 20%

The mechanism that "breaks" the linkage between linked genes is a. independent assortment. b. pleiotropy. c. incomplete dominance. d. crossing over. e. codominance.

What is an allele? a. an alternative version of a gene b. a variety of pea plant used by Mendel c. a type of chromosome d. the dominant form of a gene

A single allele that controls more than one character is said to be _____. a. pleiotropic b. polygenic c. linked d. autotrophic

Assume tall (T) is dominant to dwarf (t). If a homozygous dominant true-breeding individual is crossed with a homozygous true-breeding dwarf, the offspring will _____. a. all be intermediate in height b. all be tall c. be 1/2 tall and 1/2 dwarf d. be 3/4 tall and 1/4 dwarf e. all be short

Mendel's law of independent assortment states that a. independent sorting of genes produces polyploid plants under some circumstances. b. each pair of alleles segregates independently of the other pairs of alleles during gamete formation. c. genes are sorted concurrently during gamete formation. d. chromosomes sort independently of each other during mitosis and meiosis.

An insect that has the genotype EeGGcc will have the same phenotype as an insect with the genotype _____. a. EEGgcc b. EEggcc c. eeggcc d. EEGGCc

Varieties of plants in which self-fertilization produces offspring that are identical to the parents are referred to as a. monohybrid crosses. b. hybrids. c. true-breeding. d. the F2 generation.

What is the normal complement of sex chromosomes in a human male? a. one Y chromosome b. two X chromosomes and one Y chromosome c. two Y chromosomes d. one X chromosome and one Y chromosome

In a test cross, F2 refers to _____. a. the second filial generation, or the "grandchildren" of the original mating pair b. the original mating pair c. the 1st filial generation d. the grandparents of the 1st generation

If hair color, eye color, and the presence or absence of freckles were consistently inherited together, the best explanation would be that _____. a. gene duplications have occurred b. the genes for these characters are linked on the same chromosome c. both parents have the same hair color, eye color, and freckles d. these traits are recessive characteristics