Question

You have 3 turtles, each with a mutation that causes them to have a strange polka dotted pattern on their shells. Assume all 3 mutations are homozygous recessive. You discover that turtle 1 and turtle 3 have mutations in the same gene, while turtle 1 and turtle 2 have mutations in different genes.What phenotype would you expect from crosses between:

Answer 1

Answer:

Cross between 1 and turtle 3 produces offspring with same polka pattern as parents have.

Similarly Cross between 1 and turtle 2 produces no strange polka pattern.

Explanation:

As all three turtles have homozygous mutation. These mutations causes the polka dotted pattern on shells.

Turtle 1 and Turtle 3 both have mutation on same gene so they also have same polka dotted pattern. On crossing these two Turtles produce same polka dotted phenotype pattern.

Turtle 1 and Turtle 2 have mutations on different genes. These different genes control different characters of shell pattern hence crossing between Turtle 1 and turtle 2 produces no strange polka dotted pattern as strange polka dotted pattern always appears in homozygus repressive condition. Genes during crossing not pass in pair hence offspring contain one mutant allele of gene coming from one turtle and one normal allele of gene coming from other turtle.

Results

Cross between 1 and turtle 3 produces offspring with same polka pattern as parents have.

Similarly Cross between 1 and turtle 2 produces no strange polka pattern.