Chapter 20

Which of the following crosses could produce offspring with the recessive phenotype? a. \(A A \times a a\) b. \(A a \times A a\) c. \(A A \times A a\) d. \(A A \times A A\)

Although the amount of any particular base in DNA will vary among individuals, the amount of guanine will always equal the amount of a. thymine. b. adenine. c. cytosine. d. uracil.

Huntington's disease is caused by a dominant allele. If a mother has Huntington's disease but the father does not carry the dominant allele, what is the probability that the first child will be normal? a. \(0 \%\) b. \(25 \%\) c. \(50 \%\) d. \(100 \%\)

How many different gametes could a person with the genotype Aabbcc form? (The genes are on different chromosomes.) a. 2 b. 4 c. 16 d. 64

How many different gametes could a person with the genotype AaBbCc form? (The genes are on different chromosomes.) a. 2 b. 4 c. 16 d. 64

Cystic fibrosis is caused by a recessive allele, \(c .\) What is the probability that two people who are carriers for cystic fibrosis will have a child who is also a carrier? a. \(0 \%\) b. \(25 \%\) c. \(50 \%\) d. \(100 \%\)

A trait controlled by many genes is described as being ______________.

The _____________ of an individual is the physical expression of one or more genes of interest, and the ____________ is the set of alleles the person possesses for the gene or genes of interest.

The genotype of a person with two copies of the same allele is _______________ and the genotype of a person with two different alleles for a trait is ______________.