Chapter 9

A heterozygote has________ a for a trait being studied. a. pair of identical alleles b. pair of nonidentical alleles c. haploid condition, in genetic terms

The observable traits of an organism constitute its________ . a. phenotype c. genotype b. sociobiology d. pedigree

The offspring of the cross \(A A \times\) aa are ________. a. all \(A A\) b. all aa c. all \(A a\) d. \(1 / 2 A A\) and \(1 / 2\) aa

Assuming alleles have a clear dominance relationship, a dihybrid cross leads to a phenotypic ratio in offspring that is close to________ . 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 is ________ . a. unrelated to the distance between them b. increased if they are close together c. increased if they are far apart

If one parent is heterozygous for a dominant autosomal allele and the other parent does not carry the allele, a child of theirs has \(a\)________ chance of being heterozygous. a. 25 percent b. 50 percent c. 75 percent d. no chance; it will die

A bell curve indicates________ in a trait. a. pleiotropy b. crossing over c. continuous variation d. aneuploidy

Nondisjunction at meiosis can result in ________. a. pleiotropy b. crossing over c. continuous variation d. aneuploidy

Color blindness is a case of________ inheritance. a. autosomal dominant b. autosomal recessive c. X-linked dominant d. X-linked recessive

Klinefelter syndrome \((\mathrm{XXY})\) is easily diagnosed by ________. a. pedigree analysis b. aneuploidy c. karyotyping d. phenotypic treatment

Is this statement true or false? Body cells may inherit three or more of each type of chromosome characteristic of the species, a condition called polyploidy.

A recognized set of symptoms that characterize a specific disorder is a________ . a. syndrome b. disease c. pedigree

Match each example with the most suitable description. ________dihybrid cross ________monohybrid cross ________homozygous condition ________heterozygous condition a. \(b b\) b. \(A a B b \times\) AaBb c. \(A a\) d. \(A a \times A a\)

Match the terms appropriately. ________polyploidy ________syndrome ________aneuploidy ________nondisjunction during meiosis ________epistasis a. symptoms that characterize a genetic disorder b. extra sets of chromosomes c. gametes with the wrong chromosome number d. one gene affects another e. one extra chromosome