What is fertilization in biological terms?

Fertilization in biological terms specifically refers to the fusion of a male gamete, or sperm, with a female gamete, or egg, leading to the formation of a zygote. This union not only combines the genetic material from both parents—resulting in a unique genetic identity that contains half the chromosomes from the mother and half from the father—but also initiates the developmental processes necessary for creating a new organism. Once fertilization occurs, the zygote can undergo numerous cell divisions and eventually develop into an embryo.

This definition distinguishes fertilization from the other processes listed. DNA replication pertains to the copying of genetic material, growing an embryo involves the stages that follow fertilization, and mutation refers to changes in the DNA sequence that might occur during development but is not part of the fertilization process itself. Thus, the correct description of fertilization highlights its fundamental role in reproduction and the beginning of new life.