How many gametes will be formed in the pea plant having genotype RrTT?

Two

The correct answer is Option (2)- Two

Total possible gametes formed by a genotype is = 2ⁿ, where n is a number of genes for which it is heterozygous .

In a pea plant having genotype RrTT, number of heterozygous = 1

Total possible gametes formed by a genotype is = 2ⁿ = 2¹=2

In a pea plant having genotype RrTT two types of gametes will be formed i.e. RT and rT.