Biology :)

3. in danger of being harmed, lost, unsuccessful, etc
6. a person whose job involves discovering or verifying information
8. the state of something with regard to its appearance, quality, or working order
11. of a species, family, or other group of animals or plants) having no living members; no longer in existence
12. a group of organisms that can interbreed and produce fertile offspring

1. an invasion of the body by harmful microorganisms or parasites
2. a room or building equipped for scientific experiments
4. the natural home or environment of an animal, plant, or other organism
5. a particular kind of matter with uniform properties
7. to create copies or make more of something, whether it's offspring, copies of a document, or even a mental image
9. break down (food) in the alimentary canal into substances that can be absorbed and used by the body
10. segments of your DNA, which give you physical characteristics that make you unique