Inherited genes most clearly contribute to individual differences in

temperament

Explanation:

Temperament is the combination of innate traits we inherit from our parents that unconsciously affect our behavior. For this reason, we can say that inherited genes clearly contribute to individual differences in temperament.

It is the temperament that makes the person extrovert or introvert, that makes one person interested in sport and another in music and art. Temperament influences all our actions, from sleep, study, or eating habits, and even to the way we live everyday or relate to or communicate with others. For example, it is reflected in driving, shopping, or even font.

Obviously, temperament is not the only influence on one's life. Family education, the process of socialization, and motivation are all influential, but temperament is what, along with the color of the eyes and other physical characteristics, accompanies us throughout life.

"do a testcross with a homozygous recessive plant."

geologic time scale (for gradpoint) =)