To answer this we need to analyze each statement
camouflage, mimicry, and stingers: This is meant to escape predation and fend off predators, so this is the correct answer.
hibernation and migration: This is meant for breeding and or food energy storage, to pass hard seasons so is also incorrect.
courtship and breeding behaviors: This is meant for reproduction and to ensure offspring so this is incorrect.
nesting and food gathering: this is a behavior for survival, resource use rather than defense, si this is not correct.
The part of the neuron that carries impulses away from the cell body is the axon. Think Axon, Away.
There is 20 chromosomes in a adult wild mouse