Which of the following did Mendel select for his experiments?

How can the concept of dominance be explained?

Considering the four chromosomes in Pisum sativum, how many traits did Mendel identify for his experiments?

$A$ disease is caused by a dominant gene,but it shows only $20\%$ penetrance. $A$ heterozygous man marries a homozygous normal woman. What proportion of the children in the population is expected to have the disease?

If an offspring shows any one of the characters of either of its parents,the:

Provide definitions/explanations for the following terms:
$1.$ Genetics
$2.$ Heredity