What happens during fertilization that makes the offspring unique compared to the original cells? Please write the answer in one sentence!

During fertilization, two gametes from the parents —with different genetic information— join together to obtain a unique offspring, different from the parental cells that gave rise to it.

Explanation:

Gametes are the cells produced by each individual to transmit their genetic information to their offspring.

The process of producing gametes is called gametogenesis, and it is a reductive division called meisois. During meiotic division, crossing over occurs, allowing the recombination of genes, which results in genetic variability.

What makes the offspring different and unique from the parental generation is that, during fertilization, the genetic characteristics of both parents are mixed when two gametes are joined.