What is the $23^{rd}$ pair of chromosomes in humans called?

Mendel observed a contrasting trait in relation to the position of flowers. Mention that trait.

Explain Mendel's concept of heredity, by giving three points.

Evolution has exhibited a greater stability of molecular structure when compared with morphological structures. Comment on the statement and justify your opinion.

By the process of artificial selection in evolution, which of the following is developed using sterile flowers?

When a pure tall pea plant and a pure dwarf pea plant were crossed (hybridized),what was the result in the $F_{1}$ generation?