(N/A) Heredity: It is the transmission of characters from parents to the next generation.
Variations: The changes that occur in the $DNA$ of an organism due to mutations,recombination,or environmental factors.
$(b)$ Dominant: The trait which is able to express itself even in the presence of a contrasting trait. It appears in all the progenies in the $F_{1}$ generation.
Recessive: The trait which can express itself only in a homozygous condition. It does not appear in the $F_{1}$ generation.
$(c)$ Natural selection: It is the gradual natural process by which biological traits become either more or less common in a population based on survival advantage. Example: Green beetles surviving better than red beetles in green foliage.
Artificial selection: It is the human-driven mechanism of selecting organisms with desirable characters to bring about major changes in plants and animals. Example: Different vegetables like broccoli,cauliflower,and kale derived from the wild cabbage variety.