Section 8 & 9 Review Quiz - Basic Genetics

The tall allele, T, is dominant to the short allele, t, in Mendel's pea plant. You examine a pea plant that exhibits the tell phenotype. What is the genotype?

• Tt

• TT

• tt

• Both TT and Tt are possible.

After performing a monohybrid cross, it is important to analyze the results with a Punnett square. What does each box in a Punnett square represent?

• possible phenotype

• possible genotype

• one individual

• two possible genotypes

According to Mendel's law of segregation, what takes place during meiosis?

• pairs of alleles cross over on chromosomes, exchanging one for the other

• pairs of alleles separate in meiosis, and each gamete receives one allele of each pair

• part of an allele is separated, or broken off, from its chromosome

• one chromosome is suppressed, and the other chromosome of the pair determines the traits of the offspring

The gene for brown eyes (B) is dominant over the gene for blue eyes (b). To brown-eyed people have a blue-eyed child. Which genotype makes this possible?

• The mother and father are both homozygous brown eyed (BB).

• The mother is homozygous brown eyed (BB), and the father is heterozygous brown eyed (Bb).

• The mother is heterozygous brown eyed (Bb) and the father is homozygous brown eyed (BB).

• The mother and father are both heterozygous brown eyed (Bb).

A homozygous dominant pea plant with purple flowers is crossed with a homozygous recessive pea plant with white flowers. Which of the following describes the offspring?

• homozygous with purple flowers

• heterozygous with purple flowers

• homozygous with white flowers

• heterozygous with white flowers

Which of the following best describe's Mendel's Law of Dominance?

• When an organism has two different alleles of the same gene, both genes will be expressed equally in the organism

• When an organism has two of the same alleles for a gene, that allele is always dominant.

• When an organism has two different alleles of the same gene, one of the genes will be expressed and the other will be hidden.

• When an organism has two of the same alleles for a gene, the stronger of the two genes will be expressed.

Two heterozygous tall pea plants are crossed. They produce 16 seeds. How many of those seeds will likely result in short plants?

• 4

• 16

• 1

• 2

A heterozygous tall plant is crossed with another heterozygous tall plant. What percentage of the offspring is predicted to be homozygous recessive?

• 75%

• 25%

• 100%

• 50%

In fruit flies, straight wings are dominant over curled wings. A homozygous fruit fly is crossed with a heterozygous fruit fly. A Punnett square predicts what percentage of the offspring will be heterozygous?

• 50%

• 25%

• 75%

• 100%

In guinea pigs, brown fur is dominant over white fur. To determine if a female brown guinea pig is heterozygous or homozygous, it should be crossed with a male guinea pig known to have which of the following phenotyes?

• homozygous white

• homozygous brown

• heterozygous white

• heterozgous brown