Genetics Problems for Biology 1009

1. You have found a blue male bug and a green female bug of the same species living in the rainforest. Assume that the color difference is genetic and further that only two autosomal alleles (at the same locus) are involved. You breed the bugs (the P1 generation) and half of their offspring (the F1 generation) are blue and half are green. Given only the information above, how can you tell which allele is dominant? (1 pt)

You inbreed two of the blue bugs produced in the cross above (from the F1 generation). Of the 1000 offspring (the F2 generation) they produce, 772 are blue and 228 are green. What is the probable genotype of the blue F1 bugs? (2 pts: 1 for answer, 1 for reasoning/work)

2. You are studying two true-breeding populations of white mice, one with black noses and furry tails and the other with pink noses and bald tails. You cross a male from the first population with a female from the second population (the P1 generation) and their offspring (the F1 generation) are all black-nosed and furry-tailed. What are the possible genotypes of the F1 generation? (1pt)

If the two traits under consideration are linked and you inbreed two F1 mice, what will be the phenotype distribution of their offspring (the F2 generation)? (2 pts: 1 for answer, 1 for work)

3. Color-blindness is caused by an X-linked recessive allele. A color-blind man and a homozygous, non-color-blind woman have a daughter. How likely is the daughter to be color blind? (2 pts: 1 for answer, 1 for work)

The daughter has a son with a non-color-blind man. How likely is the son to be color blind?
(2 pts: 1 for answer, 1 for a work)

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