Tomato fruits are round and pear-shaped. A) What are the genotypes of the parent plants

Tomato fruits are round and pear-shaped. A) What are the genotypes of the parent plants, if the offspring turned out to be equally round and pear-shaped? B) In the greenhouses of a peasant farm, seedlings of tomatoes grown from hybrid seeds were planted. 31750 pear-shaped bushes of this seedling were produced, and 95250 bushes were round. How many heterozygous bushes are among them?

Let’s write down the solution scheme.

A – round fruits,

a – pear-shaped fruits.

A) Obviously, the parents had the following genotypes (splitting in the offspring 1: 1):

Parents: Aa x aa,

Gametes: A, a x a,

Offspring: Aa (round), aa (pear-shaped).

B) First, we find the phenotype splitting in the offspring: 95250/31750 = 3, or the ratio of round and pear-shaped = 3: 1. This occurs when both parents are heterozygous.

Parents: Aa x Aa,

Gametes: A, a x A, a,

Offspring: AA, 2 Aa (round fruits), aa (pear-shaped).

2/3 bushes with round fruits are heterozygous:

95250 * 2/3 = 63,500 bushes.