128 Review Questions

4. X-linked recessive traits in humans (or in Drosophila) are observed ________.

1. in more males than females
2. in more females than males
3. in males and females equally
4. in different distributions depending on the trait

5. The first suggestion that chromosomes may physically exchange segments came from the microscopic identification of ________.

1. synapsis
2. sister chromatids
3. chiasmata
4. alleles

6. Which recombination frequency corresponds to independent assortment and the absence of linkage?

1. 0
2. 0.25
3. 0.50
4. 0.75

7. Which recombination frequency corresponds to perfect linkage and violates the law of independent assortment?

1. 0
2. 0.25
3. 0.50
4. 0.75

8. Which of the following codes describes position 12 on the long arm of chromosome 13?

1. 13p12
2. 13q12
3. 12p13
4. 12q13

9. In agriculture, polyploid crops (like coffee, strawberries, or bananas) tend to produce ________.

1. more uniformity
2. more variety
3. larger yields
4. smaller yields

10. The genotype XXY corresponds to

1. Klinefelter syndrome
2. Turner syndrome
3. Triplo-X
4. Jacob syndrome

11. Abnormalities in the number of X chromosomes tend to have milder phenotypic effects than the same abnormalities in autosomes because of ________.

1. deletions
2. nonhomologous recombination
3. synapsis
4. X inactivation

12. By definition, a pericentric inversion includes the ________.

1. centromere
2. chiasma
3. telomere
4. synapse