Question

Among a species of butterflies, the color blue (B) is a dominant trait. Yellow color (b) is a recessive trait. If a pure blue butterfly (BB) mates with a pure yellow (bb), what will the offspring look like?.
A). They will all be blue..
B). They will all be yellow..
C). Half will be blue and half will be yellow..
D). About 75% will be blue and 25% will be yellow..

Answer 1

Answer - A
A pure blue butterfly, with blue being the dominant trait mates with a pure yellow butterfly with yellow being the recessive trait, the phenotype of all the offspring would be blue. However, their genotype transferred to them via both parents would be Bb. That is they would all contain one dominant gene (B:blue) and one recessive gene (b:yellow)

Answer 2

Answer:

The correct answer would be A). They will all be blue.

Genotype of the parents are BB and bb.

As both are homozygous in nature so, each will produce only one type of gamete.

BB will produce gamete B and bb will produce b as its gamete.

The cross will results in the production of offspring each with genotype Bb.

We know that blue is a dominant trait and thus it will be expressed in heterozygous condition (Bb).

Hence, all offspring would be blue in color.