Chapter 13

A heterozygous individual has a ____ for a trait being studied. a. pair of identical alleles b. pair of nonidentical alleles c. haploid condition, in genetic terms

An organism's observable traits constitute its ___. a. phenotype b. variation c. genotype d. pedigree

In genetics, independent assortment means ___. a. genes of a pair end up in different gametes. b. gene pairs separate independently of other gene pairs

The second-generation offspring of a cross between individuals who are homozygous for different alleles of a gene are called the ___. a. \(F_{1}\) generation b. \(\mathrm{F}_{2}\) generation c. hybrid generation d. none of the above

The \(\mathrm{F}_{1}\) offspring of the cross \(A A \times\) aa are ___. a. all \(A A\) b. all \(a a\) c. all \(A a\) d. half are \(A A\); half are aa

A testcross is a way to determine ___. a. phenotype b. genotype c. both a and b

Assuming complete dominance, crosses between two dihybrid \(\mathrm{F}_{1}\) pea plants, which are offspring from a cross \(A A B B \times a a b b,\) result in \(F_{2}\) phenotype ratios of ___. a. 1: 2: 1 b. 3: 1 c. 1: 1: 1: 1 d. 9: 3: 3: 1

The probability of a crossover occurring between two genes on the same chromosome __. a. is unrelated to the distance between them b. decreases with increasing distance between them c. increases with the distance between them

True or false? All traits are inherited in a Mendelian pattern.

A gene that affects three traits is ___. a. epistatic b. a multiple allele system c. pleiotropic d. dominant

The phenotype of individuals heterozygous for ____ alleles comprises both homozygous phenotypes. a. epistatic b. codominant c. pleiotropic d. hybrid

___ in a trait is indicated by a bell curve. a. Epigenetic effects b. Pleiotropy c. Incomplete dominance d. Continuous variation

Match the terms with the best description. $$ \text { dihybrid cross } \quad \quad\quad\quad\quad \text { a. \(b b\) } $$ $$ \text { monohybrid cross } \quad \quad\quad\quad\quad \text { b. \(A a B b \times A a B b\) } $$ $$ \text { homozygous condition } \quad \quad\quad\quad\quad \text { c. \(A a\) } $$ $$ \text { heterozygous condition } \quad \quad\quad\quad\quad \text { d. \(A a \times A a\) } $$