Chapter 9

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

Assuming all alleles have a clear dominant/recessive relationship, a dihybrid cross leads to a phenotypic ratio in offspring that is typically close to ____________. a. 3: 1 b. 1: 2: 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

____________ alleles are both fully and equally expressed. a. Dominant b. Codominant c. Pleiotropic d. a and b

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

Constructing a pedigree is particularly useful when studying inheritance patterns in organisms that _________. a. produce many offspring per generation b. produce few offspring per generation c. have a very large chromosome number d. have a fast life cycle

A female child inherits one \(X\) chromosome from her mother and one from her father. What sex chromosome does a male child inherit from each of his parents?

Nondisjunction at meiosis can result in ___________. a. duplications b. aneuploidy c. crossing over d. pleiotropy

True or false? All traits are inherited in a predictable way.

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

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

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. ___________ polyploid ___________ syndrome ___________ aneuploidy ___________ nondisjunction during meiosis ___________ epistasis ___________ genotype ___________ human eye color a. symptoms of a genetic disorder b. extra sets of chromosomes c. gametes end up with the wrong chromosome number d. two genes affect the same trait e. one extra chromosome f. varies continuously g. an individual's alleles