Question

please help with part A and B.

2. A yeast geneticist isolates two different haploid mutant yeast strains, Strain A and Strain B, which cannot grow unless the amino acid leucine is added to the growth media. Wild-type yeast strains can make their own leucine and do not require that it be added to the growth media. The geneticist discovers that each mutant yeast strain contains a single recessive mutation that leads to the observed leucine-requiring phenotype. When she crosses the two mutant strains together, she observes that the resulting diploid can grow without leucine added to the growth media. A. What is the name of the type of test that the geneticist performed? B. Explain the results including the likely relationship between the mutations in these two strains. 5p

Answer 1

The mutation of strain A and B can be called as Not allelic mutations but this is complementation which is observed. As the mutations are present on the on the gene A in case of strain A and in the case of the Strain B mutations are seen on the gene B and both these gene A and B are required collectively for the growth of organisms on the leucine deficient medium if any of the gene is mutated the strain might not grow on the leucine deficient t medium but when both mutated strain are crossed they show complementation and grows on leucine deficient medium.

Suppose ‘a’ is receive gene and A is dominant gene which require dominant B gene to produce the conies on the leucine deficient colonies while ‘b’ is recessive gene so the strain A has gene AAbb while strain B has aaBB genes when they are crossed they offsprings has AABB gene gens which are complementing and can grown on leucine deficient medium

AAbb x aaBB

Ab aB

AaBb

As AaBb offspring has both genes AB it can grow on the leucine deficient medium.