Succulent

having fleshy tissues designed to conserve moisture (A3, C2)

Exoskeleton

an external supportive covering of an invertebrate (A3)

Alien

a species not native to a particular area (A3, C4, R5)

Adaptive radiation

the rapid development of many species from a single ancestral population (A3, R2, R3, IS1)

Adaptation

a change in an organism or species that enables it to survive in a particular habitat (A3, C3, R3, M2, M3)