Genetics

In one species of animal, brown eyes (B) are dominant over blue eyes (b). A brown-eyed homozygous male is crossed with a blue-eyed homozygous female, as shown in the Punnett square below. What is the probability of the offspring having brown eyes?

• 0%

• 25%

• 50%

• 100%

What type of inheritance controls blood types in humans?

• incomplete dominance

• polygenic inheritance

• multiple alleles

• recessive genes

In guinea pigs, black coat color (B) is dominant to white coat color (b). What percentage of the offspring will be white when a homozygous black guinea pig is crossed with a homozygous white guinea pig?

• 0%

• 25%

• 50%

• 100%

A student is constructing a model of a single chromosome. The individual segments within the chromosome represent genes that control certain traits.

Based on the model, which term BEST describes gene pair #1.

• dominant

• heterozygous

• homozygous

• recessive

A student created the table below which shows different traits that are affected by genetics and the environment.

Which of the following BEST completes the table?

• height

• weight

• blood type

• muscular strength

Which of the following is an example of sex-linked inheritance?

• diabetes

• cystic fibrosis

• hemophilia

• albinism

A student’s mother is heterozygous for attached earlobes, a recessive trait. The student’s father is also heterozygous for that trait. What is the percent likelihood that this student has attached earlobes?

• 0%

• 25%

• 50%

• 75%

A mouse is homozygous for black fur (BB). The other parent is heterozygous for black fur with a recessive trait for brown fur (Bb). If black is the dominant trait, what percentage of the offspring will be brown?

• 100%

• 50%

• 25%

• 0%

In snapdragon plants, red flowers are dominant to white flowers. When red-flowered plants are crossed with white-flowered plants, pink flowers are produced. If a researcher wants to produce plants with only white flowers, what color should the parent plants be?

• both red

• both white

• one red and one white

• one white and one pink

Shaded individuals in this pedigree express a particular trait.

Based on this pedigree, what is the mode of inheritance of the trait?

• autosomal dominant

• autosomal recessive

• sex-linked dominant

• sex-linked recessive