How do the Earth's physical factors influence population density? When population growth increases in an area, what is happening to the birth rate and age structure of that population? (

It either increase the likelihood of people staying there or not.

Explanation:

The Earth’s physical factors influence population density by being a among things that influence where people choose to live in . Most people wanted to reside in an area nearer to their place of interest, the climate is favorable, and accessible if not to all their needs. When there is an increase in population, birth rate is high,death rate will be probably low( because the people are living in a place favourable to them) , the age structure of that population will be forming like a pyramid where most of the people comprise the younger generation.

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.

answer; i believe that the correct answer is (lung);