Genetics and DNA
Science

When a male reproductive cell (sperm) joins with a female reproductive cell (egg)
Fertilization
When a male reproductive cell sperm joins with a female reproductive cell egg fertilization. Fertilization is the process where the sperm and egg combine to form a new cell that can develop into an organism.

The breeding of plants or animals to produce desired traits
Selective breeding
The breeding of plants or animals to produce desired traits. Selective breeding. Selective breeding is when humans choose certain plants or animals with specific traits to reproduce, so the offspring have those desired traits too.