Exam 12: Inheritance, Genes, and Chromosomes

In humans, a widow's peak is caused by a dominant allele (W), and a continuous hairline is caused by a recessive allele (w).Short fingers are caused by a dominant allele (S), and long fingers are caused by a recessive allele (s).Suppose a woman with a continuous hairline and short fingers and a man with a widow's peak and long fingers have three children.One child has a widow's peak and short fingers, one has a widow's peak and long fingers, and one has a continuous hairline and long fingers.What are the genotypes of the parents?

Suppose that tall plants are crossed with short, and the progeny are medium height.The F₁ plants are then crossed, and the progeny among the F₂ have many more size classes (9) than what is typically seen in crosses involving a single gene (fewer than 4).Which is the best explanation for this outcome?

Suppose that two different groups of schmoos (an imaginary animal) live in geographically separated locations and rarely interbreed.On one occasion, a big-footed white-haired schmoo does mate with a small-footed brown-haired schmoo.Six offspring result: two big-footed schmoos with light brown hair and four small-footed schmoos with light brown hair.Which statement about the inheritance of footedness in schmoos is most likely correct?

Refer to the figure.Which letter represents the stage at which the two chromosomes have segregated and are in separate daughter cells?

Suppose in a species of beetles, some individual beetles have horns, whereas others do not, and a single gene is responsible.Individuals that are hh lack horns, individuals that are Hh have horns, and individuals that are HH die as embryos.Two horned individuals mate.Of their 60 surviving offspring, _______ should have horns.

Cytoplasmic traits in certain species of trees are passed from the male plant to all of its progeny.Compare this observation to cytoplasmic inheritance in humans.

Suppose that in corn some alleles result in higher yield, but only in the heterozygous state (Aa has higher yield than either AA or aa).If different homozygous strains of corn each have different deleterious alleles, hybrids will likely to exhibit _______, as explained by the _______ hypothesis.

Humans have _______ pairs of autosomes.

In chickens, white feathers (F) are dominant over yellow (f), long beaks (B) are dominant over short (b), and red combs (R) are dominant over pink (r).You are trying to determine any linkage, and the order of all three genes on the chromosome if they are all linked.You perform three matings of roosters and hens, with the results shown in the table. What is the arrangement of genes on the chromosome(s)?

To determine the overall probability of independent events, one should _______ the probabilities of the individual events.