Triggering of the muscle action potential occurs after:. i. acetylcholine binds to chemically-gated channels in the motor end plate.
ii. calcium ion binds to channels on the motor end plate.
iii. acetylcholinesterase is released from synaptic vesicles into the synaptic cleft.
iv. the action potential jumps across the neuromuscular junction.
v. Any of these can produce an action potential in the muscle cell.

nucleic acid molecules are incredibly complex, containing the code that guarantees the four different nucleotide units comprise dna, the nucleic acid of interest to the genealogist. and one of four nitrogen-containing molecules called nucleotides

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".

i think this picture will you.

i believe it's c. the trait for large beaks will be passed on to future generations through natural selection.

since eventually smaller beaks would have to find another source of food or even eventually just die out from the lack of food.