A pea plant is heterozygous for two genes; one controlling height, one controlling color. The genotype is written PpTt. Based on the Law of Independent Assortment, approximately what proportion of the pollen produced by this plant should have the genotype PT? A pea plant is heterozygous for two genes; one controlling height, one controlling color. The genotype is written PpTt. Based on the Law of Independent Assortment, approximately what proportion of the pollen produced by this plant should have the genotype PT? a) It is impossible to estimate without more information. b) None. c) 1/4 d) 1/2

c) 1/4

Explanation:

According to law of independent assortment during gamete formation two genes controlling different characters segregate independently of each other. When a gamete receives allele for one gene, it will not influence the allele received for another gene.

PpTt pea plant is heterozygous for both the traits. Following types of gametes (pollen) can be formed from this plant:

PT

Pt

pT

pt

Since the incidence of occurrence of one type of pollen will have no effect on the occurrence of other pollen, all of them will have equal probability of forming. Hence, 1/4 of the pollen should have the genotype PT.