Science Review

2. what is released by all organisms as they expend energy
3. domesticating animals and plants and using genetic engineering for the purposes of making life easier
4. when a new strain of virus is introduce and it spreads worldwide because there is no immunity
7. as we move up the food chain, the population of the species ________, and therefore, it has a lower biomass
9. species of different populations interacting together
11. the name of a level in a food chain
13. non-living limiting factors that determine the survival of a species
14. a symbiotic relationship where one species benefits and the other is unaffected
16. the code the white blood cells obtain from the pathogens in order to kill them
18. a fungus that is used to make bread
20. an organism that lives on or in another species

1. occupy the lowest trophic level in a food pyramid
5. a non-living germ that inserts its DNA into active cells and cannot be killed with antibiotics
6. the initials of the body's cellular defense against pathogens
8. what the white blood cells create to fight pathogens
10. the only biotic limiting factor that is independent of the density of the species
12. the earliest known organism, no nucleus, bacteria
15. a symbiotic relationship where both species benefit
17. any organism that contains a clearly defined nucleus
19. the factors that determine the survival of a species