Question

What would happen to the possible variation in gametes if the number if chromosome pairs increased from two to three?

Answer 1

If each of the pairs of chromosomes was heterozygous (what gives you the highest potential number of different gametes), then the number of possible gametes increases from 4 to 8 for a diploid organism. To figure out how many are possible, raise the number of homologous chromsomes (2 for a diploid organism) to the power of the number of chromosomes. So if you have two different chromosomes (A and B), raise 2 to the 2nd power (or multiply 2 x 2) and you have 4. If you have chromosomes A, B, and C, then you have 2^3, or 2 x 2 x 2 = 8.

To show possible combinations, AaBb gives you AB, Ab, aB, or ab. AaBbCc gives possible gametes of ABC, ABc, AbC, Abc, aBC, aBc, abC, and abc.