Question

If a cross is made between PpQqRr × PpQqRr, what will be the number of different phenotypes and genotypes respectively, in their offspring?

• A. 8 and 16
• B. 16 and 32
• C. 32 and 64
• D. 8 and 27

Answer 1

The correct option is D 8 and 27

Three contrasting heterozygous traits are taken in the given cross. Different direct mathematical formulas can be used to calculate and find the number of progeny, type of gametes, types of phenotype, types of genotype

• Types of phenotypes =$2^n$

Where n = number of heterozygous gene pairs.
n = 3
$2^3$ = 2 × 2 × 2 = 8
Therefore, 8 types of phenotypes will appear in the progeny.

• Types of genotypes = $3^n$

Where n = number of heterozygous gene pairs.
n = 3
$3^3$ = 3 × 3 × 3 = 27
Therefore, 27 types of genotypes can be seen in the progeny.