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

Filial means _____.

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

\(\mathrm{F}_{1}\) offspring of the cross \(A A \times\) aa are ______. a. all \(A A\) b. all \(a a\) c. all \(A a\) d. \(1 / 2 A A\) and \(1 / 2\) 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 \(A A B B \times\) aabb, result in \(\mathrm{F}_{2}\) 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 the distance between them c. increases with the distance between them

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

______ alleles are both expressed. a. Dominant b. Codominant c. Pleiotropic d. Hybrid

Match the terms with the best description. ______ dihybrid cross _____ monohybrid cross _____ homozygous condition _____ heterozygous condition a. \(b b\) b. \(A A B B \times\) aabb c. \(A a\) d. \(A a \times A a\)