Genetics - Monohybrid Problems
The following problems relate to albinism "a" represents the gene for albinism, "A" represents the gene for normal pigmentation.
1. If in humans, AA marries aa, what would be the expected genotypes and phenotypes, and their expected ratio (if more than one type appears) on the assumption that there are many children?
2. Aa marries aa. There are many children. What would be the expected types and ratios?
3. Aa marries Aa. If there are many children, what would the types and ratios expected be?
4. aa marries aa. What would the expected types and ratios be?
5. A normally pigmented man marries an albino woman. If their first child was an albino what would their (the parents) genotype and their child's genotype be? If they have more children what other genotypes could there be?
6. An albino man marries normally pigmented woman. They have 13 children all of whom are normally pigmented. What are the probable genotypes of the children and parents?
7. A normally pigmented man whose father was an albino marries an albino woman both of whose parents were normally pigmented. They have three children, two normally pigmented and one albino. List each of these persons and give their probable genotypes.
In Drosophila, the fruit fly, long wings "L" is dominant over vestigal wing (l).
8. In a cross between heterozygous long-winged male and a vestigal-winged female, what types and proportions of genotypes would be expected?
9. In a cross between two heterozygous long-winged flies, what types and proportions of genotypes would be expected?
10. If a heterozygous long-winged fly mated with a homozygous long-winged one, what percentage of the offspring would be expected to be homozygous long-winged? Would there be any vestigal-winged flies?
11. A long-winged fly mated with a vestigal-winged fly producing 35 long-winged and 35 vestigal-winged offspring. What are the genotypic formulas of the parents? Of the long-winged offspring? Of the vestigal-winged offspring?
12. Mating a long-winged fly with a vestigal-winged fly produced 256 offspring all of which were long-winged. What were the probable genotypes of the parents? Mating of the F1 long-winged flies together would produce what types of offspring genotypically and in what proportions?