1. Which of the following chromosomal alterations would you expect to have the most drastic consequences?
(a) inversion (b) duplication
(c) translocation (d) deletion
2. The most common lethal genetic disease in the United States is
(a) sickle-cell an emia (b) cystic fibrosis
(c) Huntington’s disease (d) hemophilia.
3. There are various procedures that can be used to detect genetic disorders before birth. Among the tests discussed in this chapter, ____ is the least invasive, while ____ carries the highest risk.
(a) chorionic villi sampling . . . amniocentesis
(b) ultrasound imaging . . . fetoscopy
(c) fetoscopy . . . chorionic villi sampling
(d) fetoscopy . . . amniocentesis
4. Tay-Sachs disease runs in Seema’s family. On a family pedigree, she saw a half darkened circle. This represented
(a) a male with Tay-Sachs (b) a female with Tay-Sachs
(c) a carrier male (d) a carrier female.
5. On a pedigree tracing the inheritance of PKU, a horizontal line joins a black square and a half-black circle. What fraction of this couple’s children would you expect to suffer from PKU?
(a) none (b) 1/4
(c) 1/2 (d) 3/4
6. Ram and Nidhi are apparently normal, but their daughter was born with alkaptonuria, an inherited metabolic disorder. If alkaptonuria is like most human hereditary disorders, the probability of their next child being born with alkaptonuria is
(a) 0 (b) 1/4
(c) 1/2 (d) 2/3
7. Several inherited disorders are much more common in close-knit religious communities, such as the Amish(Jews), than in the general population. This is at least partly due to the fact that
(a) people in such communities are more likely to marry relatives
(b) shared environmental conditions such as diet can increase mutation rate
(c) modern medical care is not widely available in such communities
(d) community members care for each other and disorders are possed on.
8. A heritable feature is a ______ and may have two or more variants called______ .
(a) trait/characteristics (b) character/traits
(c) character/factors (d) trait/factors
9. In a cross between two heterozygotes (Aa), the F2 generation will be
(a) in the ratio 1:3 heterozygous to homozygous
(b) all heterozygous
(c) in the ratio 1:1 homozygous to heterozygous
(d) in the ratio 1:3 homozygous to heterozygous
10. You set up an experiment in which you breed two populations of true-breeding pea plants. The first true-breeding population has yellow round seeds and the second has green wrinkled seeds. All of the F1 plants yield yellow round seeds. When you self fertilize the F1 the F2 generation yields a mixture of yellow round, yellow wrinkled, green round and green wrinkled seeds. What does this tell you about the alleles for seed color and shape?
(a) the recessive alleles are always expressed
(b) the alleles are on different chromosomes
(c) the two alleles for each character segregate during gamete production
(d) both genes are on the same chromosome