Question

beetles of a species come in two colors: black (b) and brown (b). if a beetle with the following alleles: bb is crossed with a beetle with the following alleles bb will any of the offspring be brown? if so, what fraction of the offspring do they constitute?
a 1/4 will be brown
b 2/4 will be brown
c 3/4 will be brown
d none will be brown

Explanation:

Step1: Determine gametes

Each parent (Bb) can produce two types of gametes: B and b.

Step2: Create Punnett square

	B	b
b	Bb	bb

Step3: Analyze genotypes

The genotypes of the offspring are BB, Bb, Bb, bb. Brown color (bb) is recessive.

Step4: Calculate fraction

Out of 4 offspring, 1 has bb genotype. So the fraction is $\frac{1}{4}$.

Answer:

A. 1/4 will be brown