POPULATION GENETICS 5. (10pts) The following are the observed ABO blood group phenotypes among a group of 600 Canadian Indians: Type O = 288, Type A = 280, Type B = 19, Type AB = 13. Calculate the gene and allele frequencies. 6. (10pts) Which of the following genotype frequencies of AA, Aa and aa, respectively, satisfy the Hardy-Weinberg principle? Show all your calculations. e) 0.25, 0.50, 0.25 f) 0.36, 0.55, 0.09
EXTRACHROMOSOMAL INHERITANCE 2. (15pts) In barley, a self-fertilizing species that can be cross-fertilized, two true-breeding strains with virescent leaves occur. In strain A, the trait is caused by a cytoplasmic gene while in strain B, it is by a recessive chromosomal gene. What phenotypes would you expect among the progeny, and in what proportions in reciprocal crosses between A and B? 4. (15pts) In corn, male sterility is controlled by maternal cytoplasmic elements. This phenotype renders the male part of corn plants (tassel) unable to produce fertile pollen; the female parts, however, remain receptive to pollination by pollen from male fertile corn plants. However, the presence of a nuclear fertility restorer gene F restores fertility ferti lity to male sterile lines. What are the phenotypes and genotypes of the offsprings in the following crosses? a. Male sterile female x Ff male b. Selfing of (a) to produce F2
QUANTITATIVE 1. (10pts) In sorghum, many widely diverse types of plants exist. In the milotypes sorghum, 4 recessive genes for short stature have been identified. They have been designated dw1, dw2, dw3, and dw4. The effect of these dwarfing genes is to shorten the internode length. A plant homozygous recessive for these 4 pairs of dwarfing genes is 16 inches tall. A plant homozygous dominant for these 4 pairs of genes is 96 inches tall. Assume these alleles contribute quantitatively, cumulative and equally for this height difference. A plant of genotype Dw1Dw1Dw2Dw2Dw3Dw3dw4dw4 was crossed to one of genotype dw1dw1dw2dw2dw3dw3Dw4Dw4. F1 and F2 generations were observed. a) What would be the heights of the F1? b) Show the range of heights expected in the F2 progeny. 3. (10pts) Two inbred strains of corn were crossed to produce an F1, which was then intercrossed to produce an F2. Data on ear length from a sample of F1 and F2 individuals gave phenotypic variances of 15.2cm2 and 27.6cm2, respectively. Why was the phenotypic variance greater for the F2 than for the F1?
Human Genetics 1. (15pts) Below is the pedigree of dwarfism in 5 generations of a family (Red = affected). What is the mode of inheritance of dwarfism? How do you explain the appearance of dwarfism in the 2nd generation when it is not found in the 1st generation?
2. (10pts) The pedigree below shows the inheritance of a recessive trait (Red = affected). What is the chance that the couple III-3 and III-4 will have an affected child?
BONUS: (5pts) You want to introduce the human insulin gene into a bacterial host in hopes of producing a large amount of human insulin. Should you use the genomic DNA or t he cDNA? Explain your reasoning.
