Question

1. The length of snakes can vary between 0.8m and 2.3 m long. In a large population of snakes there were just 2 of 2.3m length out of 560 snakes. How many genes are involved in determining this character?

2. A) The heights of two true-breeding strains of maize were both 1.75m and when crossed the F1 height was also 1.75m. Selfing the F1 produced an F2 with a range of heights from 1.59 to 1.91m. Out of the F2 of 451 plants there were 25 of the tallest. If the F1 was test-crossed, how many phenotypes would you observe?

B) The heights of two true-breeding strains of maize were both 1.75m and when crossed the F1 height was also 1.75m. Selfing the F1 produced an F2 with a range of heights from 1.59 to 1.91m. Out of the F2 of 451 plants there were 25 of the tallest. How many cm does each allele contribute to the phenotype?

3. In a cross of two trihybrids what would be the proportion of offspring carrying 3 dominant alleles?

Please shows the details in explanation, thx~

Answer 1

Answer-

1) Total 4 genes are involved.

2-A) Total phenotypes = 3

2-B) Each dominant allele contributes 0.08 m or 8 cm.

3) 20 out of 64 progeny will have 3 dominant alleles. Proportion = 31.25%

The explanation is given below: