Question

Normal fruit flies have brownish-yellow bodies, and this body color is dominant. A mutation in the gene for body color can produce flies with an ebony body color. A homozygous normal fruit fly (e+e+) is crossed with a homozygous ebony fruit fly (ee). What is the predicted outcome of this genetic cross? a Of the offspring, 75% will have brownish-yellow bodies, and 25% will have ebony bodies. b All the offspring will have brownish-yellow bodies. c Of the offspring, 75% will have ebony bodies, and 25% will have brownish-yellow bodies. d All the offspring will have ebony bodies.

Answer 1

D: All the offspring will have brownish-yellow bodies

Step-by-step explanation:

As mentioned in the question, Normal fruit flies have brownish-yellow bodies, and this body color is dominant. A mutation in the gene for body color can produce flies with an ebony body color. Here we are asked that, A homozygous normal fruit fly (e+e+) is crossed with a homozygous ebony fruit fly (ee). What is the predicted outcome of this genetic cross.

Lets cross a normal fruit fly (e+e+) with a homozygous ebony fruit fly (ee)

P1: e+e+ X ee

Gametes: e+: e+: e: e

Offspring: e+ e: e+ e: e e+ :e e+

Since, brownish-yellow bodies color is dominant, and all the offspring have genotype e+ e, this means that All the offspring will have brownish-yellow bodies.

Hope it helps!