genetics

5. cells used for reproduction
8. a long strand
9. long,thread-like structure inside cells that holds many genes
10. number of chromosomes in human egg or sperm cells
12. tiny parts in our body that are passed from our parents and decide how we look and how our body works
13. how nature chooses which living things stay alive and pass on their traits

1. the first tiny cell formed when a sperm and an egg join together
2. a group of organisms that look alike and can breed to make more of the same kind
3. when a sperm cell from a male joins with an egg cell from a female to start creating a new life
4. same species different looks
6. how parents pass traits, like eye color or height, to their children through genes
7. male reproductive cell
11. female reproductive cell