During which stage of the cell cycle does the
replication of DNA take place?

option a is correct i.e.

explanation:

in context to the membrane of nerve impulse, the outer membrane of neuron is semi permeable that is only sodium ions can pass through the membrane i.e. smaller ions can pass through the membrane while larger ions cannot pass through it.

your answer is true

i am 100% sure

explanation:

the correct answer is:

a population changes in response to a change in the environment.