Question

Three loci, mitochondrial malate dehydrogenase that forms a and b (MDHa, MDHb), glucuronidase that forms 1 and 2

(GUS1, GUS2), and a histone gene that forms + and (H+, H), are located on chromosome #7 in humans.
Assume that the MDH locus is at position 35, GUS at position 45, and H at position 75. A female whose mother
was homozygous for MDHa, GUS2, and H+ and whose father was homozygous for MDHb, GUS1, and H
produces a sample of 1000 egg cells. Give the expected numbers of the MDHa GUS2 H cells she would
produce. Assume no chromosomal interference.
A) 15 B) 235 C) 315 D) 135 E) 0

Answer 1

The expected number of egg cells with the MDHa GUS2 H genotype can be calculated by multiplying the probabilities of each genotype combination. Therefore, the expected number is 125.

Step-by-step explanation:

In this scenario, the female individual is homozygous for MDHa, GUS2, and H+ genotype, while the male individual is homozygous for MDHb, GUS1, and H genotype. The expected number of egg cells with the MDHa GUS2 H genotype can be calculated by multiplying the probabilities of each genotype combination:

MDHa (1/2) x GUS2 (1/2) x H+ (1/2) = 1/8

Since the female will produce 1000 egg cells, the expected number of MDHa GUS2 H cells would be:

1000 egg cells x (1/8) = 125

Therefore, the expected numbers of the MDHa GUS2 H cells she would produce is 125. Therefore, the correct answer is E) 0.