Exam 11: The Basic Principles of Heredity

What is an X-linked inheritance pattern? Use a specific example to explain the role of the father and mother in this unique inheritance pattern and note the differential impact on male and female offspring.

What are the predicted phenotypes of the female children from the union of a woman who is heterozygous for hemophilia and a man who has normal blood clotting characteristics? (Use the Punnett square to verify your answer.)

What are the predicted phenotypes of the male children from the union of a woman who is heterozygous for hemophilia and a man who has normal blood clotting characteristics? (Use the Punnett square to verify your answer.)

A lizard with a striped tail and a normal head crossed with one having a normal tail and a spotted head produce all normal (no stripes or spots) F₁ progeny. What progeny would be expected to be produced by mating either of the parental lizards with another that had a striped tail and spotted head, if the genes conferring stripes and spots were close together on the same chromosome?

In humans, a mutation in the phenylalanine hydroxylase gene causes phenylketonuria (PKU), which is characterized by a wide variety of medical problems. This is an example of epistasis .

The offspring of two heterozygous gray-bodied, normal-winged flies should be 50% gray-bodied/normal wings (BbRr) and 50% black-bodied/vestigial wings (bbrr) because these alleles are linked. Suppose a small number, say 15%, of the offspring are instead black-bodied with normal wings. This is most likely the result of:

A brown-eyed couple already has a child with blue eyes. What is the probability that their next child will have blue eyes, assuming that the brown eye allele is dominant and the blue eye allele is recessive?

A female black cat mated with an albino male and gave birth to 6 black kittens. When the albino male was mated with a different female black cat, 3 black cats and 2 albino cats were produced. How can you explain this genetic situation? Write genotypes for all three parental cats and offspring.

In a two-point test cross, 36 of the offspring were recombinant types. The remaining 64 offspring were parental types. How many map units separate the two loci?

Mating a pure-bred pink rose plant with a pure-bred pink rose plant will produce:

The presence of two X chromosomes supports the existence of a particular genetic locus. __________________

A couple who does not have cystic fibrosis but are both heterozygous has already had three girls with cystic fibrosis, and are hoping to have a normal child for their fourth. What are the chances that the fourth child will be a normal male?

A Barr body in a mammalian female cell represents a(n):

Which of the following represents the possible genotype(s) resulting from a cross between an individual heterozygous (Bb) and one that is homozygous (bb)?

An organism with the genotype of AaXx can produce gametes containing ____ if the two genes are unlinked.

Which of the following represents the possible genotype(s) resulting from a cross between an individual homozygous for black hair (BB) and an individual homozygous for blonde hair (bb)?

The physical location of a particular gene on a chromosome is called:

A gene that affects, prevents, or masks the expression of a gene at another locus is a(n) ____ gene.

The probability that two genes will be separated by crossing-over is related to:

Which of the following represents the possible genotype(s) resulting from a cross between one homozygous (BB) individual and one heterozygous (Bb) individual?