Reference no: EM132279823
In addition to a unique vocabulary, genetics involves a systematic process for passing alleles from parents to offspring. Use the provided problems to become more familiar with the mechanisms of inheritance as discussed in class.
1) In humans, brown eyes (B) are dominant to blue eyes (b). A woman who is heterozygous for brown eyes marries a man with blue eyes. Show the genotype and phenotype ratios expected among their children. What are the chances that one of their children will have blue eyes?
2) In humans, the ability to curl the tongue (T) is dominant to the inability to curl the tongue (t). A man who is homozygous for tongue curling marries a woman who cannot curl the tongue. Show the genotypes and phenotypes that are possible among their children.
3) A man has attached earlobes (e), but both of his parents' have free earlobes (E). What are the genotypes of the man and both parents?
4) What is the purpose of a testcross? State the genotype of the organism always used to perform a testcross.
5) In horses, a black coat (B) is dominant to a chestnut coat (b). A trotting gait (T) is dominant to a pacing gait (t). A heterozygous black, pacer is mated to a chestnut colored horse that is homozygous for trotting. Show the expected genotype and phenotype ratios among their offspring.
6) In humans, normal blood clotting (XN) is dominant to hemophilia (Xn). A heterozygous woman is carrying a child whose father has normal clotting blood. The woman does not know the sex of the child she carries. What is the chance that the unborn child is a normal clotting male? Hemophiliac male? Normal female? Hemophiliac female?