Review Questions

1.
When comparing humans (or in Drosophila), are X-linked recessive traits observed more frequently in males, in similar numbers between males and females, more frequently in females, or is the frequency different depending on the trait? 
  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
2.
Which recombination frequency corresponds to perfect linkage and violates the law of independent assortment?
  1. 0
  2. 0.25
  3. 0.5
  4. 0.75
3.
Which recombination frequency corresponds to independent assortment and the absence of linkage?
  1. 0
  2. 0.25
  3. 0.5
  4. 0.75
4.

Based on the diagram, which of the following statements is true?

This figure is titled Genetic Map Based on Recombination Frequencies in Drosophila. There are three columns and four rows. The first row is a header row and it labels the title of the figure. The second row is the header for each column. The first column header is Mutant. The third column header is blank. The third column header is Wild Type. The third row is the widest of all of the rows. Under the Mutant column in the third row are the words Short aristae, Black body, Cinnabar eyes, Vestigial wings, and Brown eyes. Under the second column in the third row are the numerical values 0, 48.5, 57.5, 65.5, and 104.5. Under the Wild Type column in the third row are the words Long aristae, Gray body, Red eyes, Normal wings, and Red eyes. The last row of the figure contains the text: Values in centimorgan c M map units; recombination frequency of 0.01 equals 1 c M.
Figure 13.14
  1. Recombination of the body color and red/cinnabar eye alleles will occur more frequently than recombination of the alleles for wing length and aristae length.
  2. Recombination of the body color and aristae length alleles will occur more frequently than recombination of red/brown eye alleles and the aristae length alleles.
  3. Recombination of the gray/black body color and long/short aristae alleles will not occur.
  4. Recombination of the red/brown eye and long/short aristae alleles will occur more frequently than recombination of the alleles for wing length and body color.
5.
Which of the following codes describes position 12 on the long arm of chromosome 13?
  1. 13p12
  2. 13q12
  3. 12p13
  4. 12q13
6.

Assume a pericentric inversion occurred in one of two homologs prior to meiosis. The other homolog remains normal. During meiosis, what structure, if any, would these homologs assume in order to pair accurately along their lengths?

  1. a V formation
  2. a cruciform
  3. a loop
  4. a pairing would not be possible