Exam 20: Chromosomes and Human Genetics

A woman is diagnosed as having the genetic disease known as Huntington's disease. It is a rare defect caused by an autosomal dominant allele. The chance for any one of her eggs to carry the gene is

Symptoms of phenylketonuria (PKU) may be minimized or suppressed by a diet low in

The failure of chromosomes to separate during mitosis or meiosis is called

In cats an X-linked pair of alleles, B and b , controls color of fur. The alleles are incompletely dominant: B produces black, b produces yellow, and Bb produces tortoise-shell. (a) A yellow cat had a litter of two tortoiseshell kittens and one yellow. What is the sex of the yellow kitten? (b) A tortoiseshell cat brings home a litter of black, yellow, and tortoiseshell kittens. The color of which sex would tell you the color of the tomcat that produced them? (c) A yellow male is crossed with a tortoiseshell female. If the female has all male kittens in her litter of four, what color(s) would they be? (d) A tortoiseshell cat brings home her litter of black, yellow, and tortoiseshell kittens. By what method could you possibly decide whether the male parent was the black tomcat next door?

The field of study that focuses on how genes determine an individual's response to a medication is

In an autosomal dominant disorder such as Huntington's, two heterozygous parents have the probability of passing the gene on to ____ percent of their children.

Choose any and all of the following that would describe a gamete that is missing one chromosome.

If two genes are almost always found in the same gamete,

Sex chromosomes do all of the following EXCEPT

A condensed, female X chromosome is called a

In which of the following does the onset of symptoms usually occur in individuals after childbearing age?

Selecting the Exception Four of the five answers listed below provide evidence that genes are located on chromosomes. Select the exception.

The maximum life expectancy for a patient with cystic fibrosis is approximately

With respect to chromosomes, the difference between normal human males and females is defined by which of the following?

Queen Victoria

An X-linked recessive gene ( c ) produces red/green color blindness. A normal woman whose father was color blind marries a color-blind man. (a) What are the possible genotypes for the mother of the color-blind man? (b) What are the possible genotypes for the father of the color-blind man? (c) What are the chances that the first son will be color-blind? (d) What are the chances that the first daughter will be color-blind?

Which protein is defective in cases of Duchenne muscular dystrophy?

Infants who are homozygous dominant for achondroplasia

A woman heterozygous for color blindness (an X-linked recessive allele) marries a man with normal color vision. What is the probability that their first child will be color-blind?

A color-blind man and a woman with normal vision whose father was color blind have a son. Color blindness, in this case, is caused by an X-linked recessive gene. If only the male offspring are considered, the probability that their son is color-blind is