1) The correct answer is: 128 combinations.
The genetic combinations that are possible through independent assortment can be calculated as 2^n; where n is the number of different chromosomes.
So, using this formula for 7 chromosomes:
2^7 = 128 different combinations.
2) For a zygote produced by two barley parents, the number of possible genetic combinations can be calculated as: 2^n * 2^n
So, for 7 chromosomes: 2^7 * 2^7=16384
