Genotypes and phenotypes of human blood. Example with type A and type B parents resulting in a type O child.

A man with type A blood marries a woman with type B blood. Their child has type O blood. What are the genotypes of these individuals? What other genotypes, and in what frequencies, would you expect from offspring of this marriage? Give the phenotypes for the possible offspring.

Potential problems with transgenic mouse strains.

You have created 3 independent mouse strains carrying the same transgene by non-targeted transgenesis. All 3 strains have otherwise identical genetic backgrounds, yet all 3 have different phenotypes. What are potential explanations for this phenotypic variability?

Understanding the chromosome theory of inheritance.

Mr. Green is heterozygous for one autosomal gene pair, "Bb", and he carries a recessive x-linked gene "d". What proportion of his sperms will be "bd"? (a) 0 (b) 1/2 (c) 1/8 (d) 1/16 (e) 1/4

Predicting the number of chromosomes present in a human cell during various phases of cell division.

Human cells normally have 46 chromosomes. For each of the following stages, state the number of chromosomes present in a human cell. (a) Metahpase of mitosis (b) Metaphase I of meiosis (c) Telophase of mitosis (d) Telophase I of meiosis (e) Telophase II of meiosis (For the purposes of this question, consider chromatids to be chromosomes)

Understanding and predicting karyotypes.

Suppose that two interesting RARE cytological abnormalities are discovered in the karyotype of a human male. There is an extra piece (or satellite) on ONE of the chromosomes of pair 4, and there is an abnormal pattern of staining on ONE of the chromosomes of pair 7. Assuming that all the gametes of this male are equally viable, what proportion of his children will have the same visible karyotype as he has? (A karyotype is the total visible chromosome complement of an individual.)