The specialized cells, that allow a squid to flash red light when threatened, provide the structural adaptation called __.

A.) mimicry
B.) bioluminescence
C.) circadian rhythm
D.) camouflage

A hard shell, stinging cells and sharp spiny projections are examples of __.

A.) structural adaptations for defense.
B.) behavioral adaptations for mating
C.) behavioral adaptations for defense
D.) structural adaptations for cammouflage