Exam 12: Inheritance, Genes, and Chromosomes

Geneticists have discovered the existence of meiotic drive genes, which have alleles that, when present in a heterozygous state, are able to become incorporated into much more than 50 percent of the gametes.As a result, the offspring ratios are not what Mendel would have predicted.Which statement about these meiotic drive genes is true?

The theory of _______ inheritance proposes that the units of hereditary determinants remain stable and are not lost, across generations.

In Netherlands dwarf rabbits, a gene showing incomplete dominance produces three phenotypes.Rabbits that are homozygous for one allele are small; individuals that are homozygous for the other allele are deformed and die; individuals that are heterozygous are dwarf.If two dwarf rabbits are mated, what proportion of their surviving offspring are likely to be dwarf?

The process in bacteria that is most analogous to sexual reproduction is called _______.

Mendel's results demonstrated that

Sex in humans is determined by

Brown eyes are autosomal recessive to red eyes in Drosophila.A red-eyed fly is crossed to a brown-eyed fly.If that red-eyed fly is heterozygous for the allele for brown eyes and produces 80 offspring, _______ of those offspring should have brown eyes.

A certain species of fish has alleles for red scales and for blue scales.Mating a red-scaled fish to a blue-scaled fish yields fish with a patchwork of red and blue scales.Mating one of these patchwork fish to a blue-scaled fish yields half patchwork and half blue-scaled fish.What can you conclude about the red and blue alleles?

In Drosophila, the recessive allele p, when homozygous, determines pink eyes.Pp or PP results in wild-type eye color.On the same chromosome of Drosophila that carries the p (pink eyes) locus there is another locus that affects the wings.Homozygous recessives, byby, have blistery wings, while the dominant allele By produces wild-type wings.The P and By loci are very close together on the chromosome; that is, the two loci are tightly linked.Assume that no crossing over occurs, and that the F₂ generation is produced by interbreeding the F₁ progeny.For the cross PPbyby  ppByBy, what is the phenotype ratio of the F₂ generation?

Cleft chin is an X-linked dominant trait.Assume that a man with a cleft chin marries a woman with a round chin.What percent of their male progeny will show the cleft chin trait?

Refer to the figure showing a pedigree. What is the most likely mode of genetic transmission?

The genetic disease blue sclera is determined by an autosomal dominant allele.The eyes of individuals with this allele have bluish sclera.These same individuals may also suffer from fragile bones and deafness.This is an example of

You are crossing different varieties of snapdragons to get different colored flowers.After crossing one of your red-flowered plants to one of your white-flowered plants, you get pink-flowered plants.This pattern of inheritance shows _______.

Suppose that a genetics researcher concludes that the probability of obtaining a double dominant phenotype in an F₂ cross is 9/16.This conclusion can be valid only if one or more assumptions are true.Which assumption is necessary?

A man has a rare dominant autosomal trait.There is a _______ probability that one of his grandchildren will have the disease.

Egg and Fluffy are two genes in a bird that are 16 map units apart.The E allele of Egg produces large eggs, and the e allele produces small eggs (E is dominant).The F allele produces fluffy feathers, and the f allele produces nonfluffy feathers (F is dominant).In a cross of EeFf with eeff, _______ percent of the offspring should produce large eggs and fluffy feathers.

The genes a, b, and c are different genes that reside on the same chromosome.Genes a and b are 10 cM apart, b and c are 2 cM apart, and a and c are 8 cM apart.What is the order of these genes?

Separation of the alleles of a single gene into different gametes is called

You are a lab assistant working with Drosophila.You suspect that vestigial-winged flies may have contaminated a vial of wild-type flies.You know that vestigial wings are recessive to the wild type.The best way to tell whether a male fly with normal wings taken from the questionable vial is homozygous wild type is to mate it to females that you know are _______.The male is homozygous wild type if _______.

In humans, red-green color blindness is determined by an X-linked recessive allele (a), whereas eye color is determined by an autosomal gene, where brown (B) is dominant over blue (b).If a blue-eyed mother with normal vision has a brown-eyed, color-blind son and a blue-eyed, color-blind daughter, what are the genotypes of both parents and children?