Which of the following terms represents a pair of contrasting characters?

How many pairs of contrasting traits were selected by Mendel for his study on garden peas?

Mendel published his work on the inheritance of characters in $1865$,but it remained unrecognized until $1900$ because:
$(a)$ He could not provide any physical proof for the existence of factors.
$(b)$ His concept of factors as stable,discrete units that controlled the expression of traits did not find acceptance from his contemporaries.
$(c)$ Mendel's approach of using mathematics to explain biological phenomena was considered ahead of its time and unconventional.
$(d)$ Communication was not easy (as it is now),and his work could not be widely publicized.

$A$ factor (allele) is dominant if it is expressed in ...............

What are the characteristic features of a true-breeding line?

Which of the following characters is dominant in a pea plant?