Question

In humans, the dominant allele N causes an abnormal shape of the patella in the knee, whereas n is the recessive normal allele. A separate gene is concerned with finger length, and the dominant allele B causes abnormally short fingers, whereas b is the recessive normal allele. A study focused on people who have both abnormal patellae and short fingers. These individuals were N/n . B/b in genotype, having inherited the N allele from one parent and the B allele from the other parent. These N/n . B/b people mated with normal spouses, producing 40 progeny classified as follows: Normal 3 Abnormal knees and short fingers 2 Abnormal knees only 17 Short fingers only 18

Explain why the four types of children were found in the proportions shown.

Draw the chromosomes of (i) the parents of the N/n . B/b individuals; (ii) the N/n . B/b individuals; and (iii) the four types of children, showing the proper positions of the alleles based on the data above.

Answer 1

1) Children were found in the proportions shown because the two genes are linked, they do not assort independently from each other

2) The chromosomes draw is in the attached file

Explanation:

Due to technical problems, you will also find the explanation for the first question in the attached files (PDF).