Exam 12: Inheritance, Genes, and Chromosomes

Suppose your paternal grandmother has a rare mitochondrial mutation.It is likely that your father _______ (has / does not have) the mutation and that you do not have the mutation.

One particular allele of a gene may be defined as _______, or standard, because it is present in most individuals and gives rise to an expected trait, or phenotype.

A dominant allele (K) is necessary for normal hearing.A dominant allele (M) at a different, unlinked locus results in deafness no matter which other alleles are present.If a kkMm individual is crossed with a Kkmm individual, _______ percent of the offspring will be deaf.

Agouti is a type of coat color pattern in mice that cannot be expressed in albinos (white mice).A nonalbino agouti mouse that is heterozygous at the albino (A) and agouti (B) loci (AaBb) is mated to an albino mouse that is heterozygous at the agouti locus (aaBb).Nonalbino mice without the dominant agouti allele (AAbb and Aabb) are black.What percent of the progeny would you expect to be albino?

The blue sclera allele has 75 percent penetrance for producing blue sclera, 60 percent penetrance for fragile bones, and 40 percent penetrance for deafness.If these probabilities of penetrance are independent, _______ percent of individuals with the blue sclera allele will have deafness, blue sclera, and normal bones.

Genes A, B, C, D, and E are linked on the same chromosome.Locus A and locus B recombine with 10 percent frequency.Locus A and locus C recombine with 23 percent frequency.Locus B and locus D recombine with 4 percent frequency.Locus D and Locus E do not recombine.Based on this information, which of the pairs of loci are most likely to be closest together?

Curly wing is recessive to straight wing in Drosophila.If, in a cross between true-breeding curly-winged and straight-winged flies, there are 300 flies in the F₂ generation, _______ should have straight wings.

Which number cannot be a value for a probability?

Which statement about haploid organisms is true?

What are the two most accepted hypotheses for hybrid vigor?

A particular genetic cross in which an individual with a dominant phenotype and an unknown genotype is crossed with an individual known to be homozygous for a recessive trait is referred to as

In a species of mice, short hair is dominant to long hair.If a short-haired individual is crossed with a long-haired individual and both long- and short-haired offspring result, one can conclude that

Refer to the table.In Drosophila, white (w), eosin (w^e), and wild-type red (w⁺) are multiple alleles at a single locus for eye color.This locus is on the X chromosome.A female that has eosin (pale orange) eyes is crossed with a male that has wild-type (red) eyes.All the female progeny are red-eyed; about half the male progeny have eosin eyes, and about half have white eyes.Assume the female has two X chromosomes and the male has one X and one Y. What is the order of dominance of these alleles?

Suppose that in a plant the smooth seed character (SS) is completely dominant over the wrinkled seed character (ss).If the characters for height are incompletely dominant-such that TT is tall, Tt is intermediate, and tt is short-what will result from crossing a smooth-seeded short plant (SStt) with a wrinkled-seeded tall plant (ssTT)?

Geneticists make use of _______ frequencies to create genetic maps that show the position of genes on a chromosome.

If the dominant allele A is necessary for hearing in humans, and another allele, B, located on a different chromosome, results in deafness no matter what other genes are present, what fraction of the offspring of the marriage of aaBb  Aabb will be deaf?

What fraction of offspring of the cross AaBb × AaBb would be homozygous for both the dominant alleles, assuming that they are on different chromosomes?

In the genetic cross AaBbCcDdEE  AaBBCcDdEe, what fraction of the offspring will be heterozygous for all of these genes (AaBbCcDdEe)? Assume all genes are unlinked.

Compare the closely related concepts of penetrance and expressivity.

Segregation of alleles occurs