To determine the heterozygosity of an organism,one has to perform:

State the contributions of the following scientists: Gregor Mendel and Reginald $C$. Punnett.

Discuss the seven pairs of contrasting traits in pea plants studied by Mendel.

How many pairs of true-breeding pea plant varieties were selected by Mendel,which were identical except for one character with contrasting traits?

How many pairs of contrasting traits did Mendel select for his experiments (in $pairs$)?

$A$ common test to find the genotype of a hybrid is by