Genetic Crosses Discussion
I’m working on a biology multi-part question and need an explanation and answer to help me learn.
Birds have the sex chromosomes Z and W. Males are ZZ and females are ZW. If long tail feathers in turkeys is caused by a recessive allele on the Z chromosome, and a cross between a male and female with short tail feathers produces 100% of males with short tail feathers and 50% of females with short and 50% of females with long feathers, what were the genotypes of the original male and female turkeys? Show your work/reasoning.
Following a forward genetic screen you identify a number of mutants that cause flies to have shortened legs, a recessive trait. Following a complementation test you find that two separate genes have been mutated. Let S represent gene1 and L represent gene2. You cross flies homozygous for a mutant gene1 (ssLL) to flies homozygous for a mutant gene2 (SSll) together to make a heterozygous dihybrid. If you cross these heterozygous sibling flies together,
- What are the gametes produced by each heterozygous sibling?
- What would be the expected genotypes observed in the offspring?
- What would be the ratio of phenotypes that you would expect to see in the offspring
