Question

One fourth of the plants resulting from a certain cross are expected to show a trait controlled by a recessive allele. If 675 plants resulting from the cross display a trait controlled by a dominant allele, how many plants will show the trait controlled by the recessive allele?

Answer 1

The number of plants showing the trait controlled by the recessive allele can be calculated using a proportion and the given information.

Step-by-step explanation:

In a cross between plants with dominant and recessive alleles, one fourth of the resulting plants are expected to show a trait controlled by the recessive allele. If 675 plants from the cross display a trait controlled by the dominant allele, we can calculate how many plants will show the trait controlled by the recessive allele.

Since the ratio of dominant to recessive plants is 3:1, we can set up a proportion:

(675 dominant plants) / (1 dominant allele) = (X recessive plants) / (1 recessive allele)

Cross multiplying and solving for X, we find that X = 225. Therefore, there will be 225 plants that show the trait controlled by the recessive allele.