Question

In piranha, fish with large teeth represent the dominant trait. Because the dominant trait masks the recessive trait, in a population of 1,000 piranhas, all with large teeth, we could expect about ________of the next generation of fish to have small teeth.A)0%B)25%C)50%D)100%

Answer 1

Answer:

B. 25%

Explanation:

Assuming the trait for teeth size is represented by the allele A. large teeth size is dominant and will be represented by A while small teeth size will be represented by a.

Assuming that the population of 1,000 [piranhas are all heterozygotes and they crossbreed with one another:

Aa   x   Aa = AA, Aa, Aa and aa

The ration of piranhas with large teeth to that of the small teeth is 3:1 or 75:25.

Hence, about 25% of the next generation of the population is ecpected to have small teeth.

The correct option is B.