| 1 | acclimate | to become adjusted to a new environment | Hard |
| 2 | allele | one form of a gene at a particular position | Hard |
| 3 | ancestral | related to earlier generations | Hard |
| 4 | aquatic | living or occurring in water | Hard |
| 5 | biome | a large region defined by climate and living communities | Hard |
| 6 | camouflage | features that help an organism blend into surroundings | Hard |
| 7 | carnivore | an animal that eats other animals | Hard |
| 8 | coexist | to live in the same area at the same time | Hard |
| 9 | colony | a group of organisms living closely together | Hard |
| 10 | commensal | benefiting one species without clearly affecting another | Hard |
| 11 | dispersal | movement of organisms or seeds to new areas | Hard |
| 12 | endemic | naturally found in one particular region | Hard |
| 13 | forage | to search for food in the environment | Hard |
| 14 | gene | a unit of inherited biological information | Hard |
| 15 | genome | an organism's complete set of genetic material | Hard |
| 16 | germinate | to begin growing from a seed or spore | Hard |
| 17 | host | an organism that supports another organism | Hard |
| 18 | immune | able to resist a particular disease or effect | Hard |
| 19 | keystone | having an unusually large ecological influence | Hard |
| 20 | lineage | a chain of descent through generations | Hard |
| 21 | metabolic | related to the chemical processes of life | Hard |
| 22 | mutualism | a relationship in which both species benefit | Hard |
| 23 | niche | the role of a species in its environment | Hard |
| 24 | offspring | young produced by a parent organism | Hard |
| 25 | parasite | an organism living on or in a host at its expense | Hard |
| 26 | phenotype | observable traits shaped by genes and environment | Hard |
| 27 | pioneer | among the first organisms to occupy an area | Hard |
| 28 | propagation | the spread or reproduction of an organism | Hard |
| 29 | predation | the act of hunting and eating another organism | Hard |
| 30 | sedentary | remaining in one place rather than moving widely | Hard |
| 31 | succession | gradual change in a biological community over time | Hard |
| 32 | taxonomy | the classification of living things | Hard |
| 33 | trophic | related to feeding roles in an ecosystem | Hard |
| 34 | vascular | having vessels that move fluids through a body | Hard |
| 35 | viability | the ability to live or develop successfully | Hard |
| 36 | vulnerability | susceptibility to harm or disturbance | Hard |
| 37 | coevolution | reciprocal evolutionary change between species | Hard |
| 38 | depletion | a large reduction in the amount of a resource | Hard |
| 39 | fermentation | chemical breakdown driven by microorganisms | Hard |
| 40 | regeneration | renewal of lost or damaged living tissue | Hard |