The barley plant has seven pairs of chromosomes. for a gamete, the number of genetic combinations that are possible through independent assortment is . for a zygote produced by two barley parents, the number of possible genetic combinations is .

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

128 & 16,384

hope this helped:)

oxygen = 21% of the atmosphere

nitrogen = 78%

carbon dioxide = 0.1%

argon =0.934%