Answer:
a) Homozygous
Explanation:
An organism in which the two copies of the gene are identical is called homozygous in that gene. An organism with two different alleles of the genes is called heterozygous.
The answer would be the first one :)
The answer to this is older, but it's not a proven fact even though schools teach it as if it were. It is still just a theory if you think about it with how much the earth moves, areas of rock could be complete upside down and no one would know, it would be like history in reverse.
If a bacterium cannot use citrate agar will not change its color (stays green). On the other hand, if bacteria have the ability to use citrate, the medium will change its color from green to blue.
This happens because citrate agar contains pH indicator such as bromothymol blue which transforms from green to blue in alkaline conditions.