How many pairs of contrasting characters in pea plants were studied by Mendel in his experiments?

The pod character, specifically the green colour in pea plants, is:

Select the incorrect statement with respect to a reciprocal cross.

How many types of gametes can be produced by an organism with the genotype $AABBCC$?

Given below are two statements:
Statement $I$:
Mendel studied seven pairs of contrasting traits in pea plants and proposed the Laws of Inheritance.
Statement $II$:
Seven characters examined by Mendel in his experiment on pea plants were seed shape and colour,flower colour,pod shape and colour,flower position and stem height.
In the light of the above statements,choose the correct answer from the options given below:

The branch of zoology dealing with the study of similarities and differences between individuals related by descent is known as: