By what name is the branch of biology related to the study of heredity and variation known as?

Study the following cross and the self-pollination in $F_1$. Fill in the blank and answer the question that follows:
Parents: $RRYY \times rryy$
(Round,yellow) (Wrinkled,green)
$F_1$: $RrYy \times$ ?
(Round,yellow)
What are the combinations of characters in the $F_2$ progeny? What are their ratios?

$A$ zygote which has an $X$-chromosome inherited from the father will develop into a

Why is it that asexual reproduction produces exact copies, but sometimes minor variations are also seen in the next progeny?

An organism which is a worm,has very simple 'eyes',that are really eye spots which detect light. Name that organism.

$(a)$ Explain why the wing of a bat and the wing of a bird are considered to be analogous organs.
$(b)$ List two factors that lead to the formation of a new species.