During a conversation with a friend, you tell him that you recently learned in your biology class that acetylcholine release by a motor neuron triggers an action potential in a muscle fiber, causing it to contract. your friend tells you that he heard that botox injections into facial muscles underlying the skin inhibit contraction of the muscles that cause a particular type of facial wrinkle. he asks how botox does this. what will you tell him

Explanation:

Botulinum toxin (Botox) is a neurotoxic protein produced by the bacterium Clostridium botulinum and related species

Botulinum toxin commonly acts by binding to high-affinity recognition sites on the cholinergic nerve terminals and decreasing the release of acetylcholine, causing a neuromuscular blocking effect. Through this mechanism, muscle movement is inhibited in the area it is injected to.

any abiotic or biotic factor in an ecosystem that causes a population's size to slow or decrease is a limiting factor.

in 1859, charles darwin set out his theory of evolution by natural selection as an explanation for adaptation and speciation. he defined natural selection as the "principle by which each slight variation [of a trait], if useful, is preserved".