What is the definition of epistasis?(1 point)

Question

when one trait is determined by multiple genes
when one trait is determined by multiple genes

when a dominant allele for a specific trait is not completely expressed over the recessive allele
when a dominant allele for a specific trait is not completely expressed over the recessive allele

when one gene affects multiple phenotypes
when one gene affects multiple phenotypes

when the allele of one gene interferes with the expression of another gene

Answer 1

The definition of epistasis is when the allele of one gene interferes with the expression of another gene.

Answer 2

In humans, dimples are a dominant trait. Predict the percentage of children that will have dimples if one parent is heterozygous for dimples and the other parent does not have dimples.(1 point)
Responses

50 percent
50 percent

0 percent
0 percent

25 percent
25 percent

100 percent

Answer 3

If one parent is heterozygous for dimples (Dd) and the other parent does not have dimples (dd), the possible genotypes of their children would be:

• 50% Dd (dimpled)
• 50% dd (no dimples)

Therefore, the percentage of children that will have dimples is 50 percent.

Answer 4

Consider that a plant with genotype RR has red flowers and a plant with genotype WW has white flowers. This plant species expresses incomplete dominance for flower color when the plant is heterozygous. The offspring of a cross between an RR plant and a WW plant would be(1 point)
Responses

all white.
all white.

pink and white.
pink and white.

all pink.
all pink.

red and pink.

Answer 5

In incomplete dominance, the heterozygous offspring express a blend of the traits from both parents. If the red-flowered plant has the genotype RR and the white-flowered plant has the genotype WW, the offspring (heterozygous RW) would have a phenotype that is a blend, typically represented as pink flowers.

Therefore, the correct response is all pink.

Answer 6

If a homozygous white horse and a homozygous black horse are bred together, what percentage of the offspring will be roan and express both colors in their hair?(1 point)
Responses

100 percent
100 percent

50 percent
50 percent

25 percent
25 percent

0 percent

Answer 7

If a homozygous white horse (let's denote this as WW) is bred with a homozygous black horse (BB), all offspring will be heterozygous (WB).

In the case of horses, the roan color phenotype usually appears when an individual has both black and white hairs (a mix of colors), often expressed when a heterozygous combination leads to such an appearance.

However, since the question states you are breeding homozygous white (WW) and homozygous black (BB), and if we assume that the cross results in 100% heterozygous WB, these offspring would not express the roan phenotype.

Thus, the percentage of the offspring that will be roan and express both colors in their hair is 0 percent.

Answer 8

A genetic disease is found in a family that affects the immune system, lungs, heart, and kidneys. A DNA analysis of several affected and unaffected family members determines that the disease is caused by a mutation in a single gene. What type of inheritance pattern is shown in this disease?(1 point)
Responses

incomplete dominance
incomplete dominance

pleiotropy
pleiotropy

codominance
codominance

polygenic trait

Answer 9

The disease affecting multiple organ systems (immune system, lungs, heart, and kidneys) due to a mutation in a single gene demonstrates a concept known as pleiotropy. This is when one gene influences multiple phenotypic traits.

Therefore, the correct response is pleiotropy.