Solutions For An Introduction to Genetic Analysis Chapter 17 Problem 60P

a) The pairing configuration which will be seen at metaphase 1 is shown in the following diagram. The 1 and 2 chromatids are the two copies of the second strand given. The sequence would be a-b-c-d-e-f-g-h-i. The 3 and 4 chromatids are the two copies of the first strand given. The sequence of the strand would be A-B-C-D-E-F-G-H-I.

b) The results of the recombination events after the crossovers between the C and D loci and between G and H loci would result in the anaphase stage as shown. Due to the crossover, the sequence of the strand would be A-B-c-d-E-F-g-h-I. The sequence of the second strand would be a-b-C-D-e-f-G-H-i.

c) The chromosome pattern seen at anaphase 2, with the inclusion of the recombination events occurred, can be shown in the following diagram:

d) The chromosomes which are numbered 3 and 4 will give rise to viable progeny. If all gametes are fertilized by pollen that has the gene order of A-B-C-D-E-F-G-H-I, the gametic combinations would be as follows:

• A-B-C-D-E-F-G-H-I/a-b-c-D-E-F-G-H-I

• A-B-C-D-E-F-G-H-I/a-b-c-d-h-g-f-e-i