Question

in the displayed cross, brown hair (h) is dominant over blonde hair (h) and green eyes (g) is dominant over blue eyes (g).
hg hg hg hg
hg
hg
hg
hg
which fraction of the offspring are heterozygous brown and heterozygous for green eyes?
1/16
3/16
4/16
1/2

Explanation:

Step1: Analyze the Punnett square

Count the total number of offspring. There are 16 boxes in the Punnett square.

Step2: Determine the genotype for heterozygous brown and heterozygous green eyes

The genotype for heterozygous brown hair is \(Hh\) and for heterozygous green eyes is \(Gg\). Looking at the Punnett square, count the number of \(HhGg\) genotypes.

Step3: Calculate the fraction

There are 4 \(HhGg\) genotypes out of 16 total. So the fraction is \(\frac{4}{16}=\frac{1}{4}\)

Answer:

\(\frac{1}{4}\)