An organism possessing two identical alleles for a particular trait is known as:

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:

Statement-$1$: Alleles are slightly different forms of the same gene.
Statement-$2$: The segregation of alleles is a random process and so there is $50$ percent chance of a gamete containing either allele.

What is involved in a test cross?

Mendel obtained pure-breeding pea lines by:

Genetic traits are the result of ........