Question

Use the information below to answer questions 1-2. Leather back turtles (Dermochelys coriacea) lay 50 eggs per clutch on soft sand beaches. Let us assume that the first and second cleavage within the developing eggs is controlled by the presence of a single pair of codominant alleles, CA and C Full cleavage and development to maturity will occur if an offspring bears alleles in the heterozygous (CAC) condition. However, there is only 18% cleavage penetrance if C Cappears in the homozygous condition and 23% penetrance if CC appears in the homozygous condition. The remaining eggs do not proceed past the second cleavage stage of development 1. What is the genotypic ratio expected among the Fi progeny when turtles with a heterozygous genotype are mated? (1 pt) Phenotypic ratio 2. Assume that after mating, the female of the cross described in the previous question laid a clutch of 50 eggs. How many of these eges can be expected to produce live young? (4 pts) Use the information below to answer questions 35. A renetics student was asked to select true breeding white beetles for a mating experiment The student was able to obtain female white beetles from company A and white males from company B Since all beetles were of the same species the student expected that they were true breeding and performed the cross. However, the student observed the following phenotypes among the propery produced by her cross 275 white beetles 70 orange beetles 24 yellow beetles 3. Determine the phenotypic ratio observed by the student among her Fipropeny (4 pts)

Answer 1

1. When the heterozygous turtles are mated ,then the genotypic ratio will be 1:2:1 and phenotypic ratio will be 3:1 as this question follows Mendels principle .It is the same as selfing of heterozygous character.