Imagine a dihybrid cross. if there are 1000 progeny (we are talking about beetles here), approximately how many beetles would you expect to be homozygous recessive for both traits?

We would expect 63 snails to be homozygous recessive for both traits.

Explanation:

Dihybrid cross

This is a cross between two distinct groups with different observed traits. Independent segregation is observed on the allelic pair for the genes in the separate chromosomes.

The first filial generation produces 4 similar offspring, the second filial generation, would demonstrates a phenotypic ratio of 9:3:3:1.

On dividing the 1,000 progeny on the aspect of phenotypic ratio 9:3:3:1, we can infer an approximate number of 63 (62.5) snails to be homozygous recessive for both traits.

We will calculate on the aspect of the phenotypic ratios and proportions,

Therefore

9+3+3+1 = 16.

1,000*1/16 = 62.5

62.5 can be approximated to 63