XYY disorder is a hereditary condition in which a human male has an additional male (Y) chromosome, giving an aggregate of 47 chromosomes rather than the more regular 46. The "XYY" chromosome hypothesis drop out of support as a clarification for criminal conduct is on account of thought most lawbreakers don't have XYY and everybody with XYY is not a criminal
The correct answer is option C, that is, behavioral isolation.
The phenomenon of behavioral isolation takes place when two populations possess the tendency of interbreeding, but exhibit distinctions in courtship rituals or other kinds of behavior. For example, the western and eastern meadowlarks are very identical birds whose habitat overlap in the middle of the United States.
However, the members of the two species will not mate with each other, possibly as they use different songs in order to fascinate males. The eastern meadowlarks will not respond to the songs of western meadowlarks, and vice versa.
I think I understand even without the picture. I'll add a picture of the Punnett Square filled in, but what you're crossing is
Tt x tt (heterozygous crossed with a homozygous recessive)
The ratio you get in the end is 2 heterozygous (Tt) and 2 homozygous (tt) offspring, so the ratio is 1:1.
So the percentage of offspring that are homozygous recessive is 50%.
The earliest forms would be plants and other life like that, and current day would be mostly humans and animals and a lot of plants are disappearing