Solution:
if a human individual were heterozygous for 23 genes on 23 different chromosomes the following gametic combination is possible:
With respect to chromosome is 1 then, the individual can produce 2 kinds of gametes. With respect to chromosome number 2, also 2 kinds. So, the equation is:
Number of different gametes = 2^n where n is the number of chromosomes. So,
2^23 = 8.4X10^6 different gametes.