1: Sexual reproduction
The type of reproduction in which fusion of gametes coming from two different individuals takes place is referred to as sexual reproduction.
2: Sexual reproduction as a resort
Sexual reproduction acts as a resort in unfavorable conditions because of the following:
● Fusion of gametes combines genetic material of different individuals giving rise to a combination of traits.
● Recombination during meiosis promotes evolution.
● It mediates survival during unfavorable conditions. Algae and fungi often switch to sexual mode of reproduction during unfavorable conditions. This ensures the survival of the fittest and continuity of species.