The presence of a specific trait is genetically inherited. there are only two possible outcomes for this trait: an individual either inherits the trait or does not inherit the trait which statement best describes how parents influence this trait

a)each parent contributes one nitrogenous base for this trait

b) each parent contribute two chromosomes for this trait

c)each parent contribute two genes for this trait

d) each parent contributes one allele for this trait

D) Each parent contributes one allele for this trait  

Explanation:

All traits of individuals are determined by specific genes of that trait. For example, there is a certain gene for height, certain gene for eye color, face shape etc.

Genes are the units of hereditary, and for every trait there is one gene in every organism. However, one gene is present in two alternative forms called alleles in an organism. For example: There is a trait height, a person has two alleles for the height gene, one allele is for short height, and other allele is for tall height. The trait of tallness is dominant over the trait of shortness, Therefore, this person will have tall height.

Now the alleles are transmitted from parents to offspring. Every parent contributes one allele for a specific trait, in the process and transmit it to offspring.

The allele which will be dominant will be expressed while the one that is recessive will e suppressed.

Therefore, option D is the right answer.

Hope it helps!