Guinea pig coat color is determined by a single gene. the allele for black coat color is dominant to brown. in a cross between two black-haired guinea pigs, 20 offspring are born. if both parents were heterozygous, probability would predict that approximately how many of the 20 offspring would have brown hair?

I will indicate the black gene as "B" and the brown gene as "N".

The parents would be "B-N" since they are both heterozygous. If they were homozygous, they would be "B-B".

There are 4 combinations of outcomes for the offspring: B-B, B-N, N-B and N-N. Since 3/4 of the outcomes have black hair (because they have at least 1 black gene), that leaves 25% that will have brown hair.

25% of 20 is 5. (5 of the offspring should have brown hair.)

Hope it helps.

Ribonuclease activity is a type of nuclease that catalyzes the degradation of rna into small components.