Answer:
Water, carbon dioxide, and oxygen are among the few simple molecules that can cross the cell membrane by diffusion (or a type of diffusion known as osmosis ). Diffusion is one principle method of movement of substances within cells, as well as the method for essential small molecules to cross the cell membrane.
Explanation:
This can be identified as a population. In a population, the organisms are the same species and they have to live in the same area. For example, the population of cities are the head count of the species of human in that one area.
Answer:
Older rock layers are found under younger rock layers
Explanation:
It directly states in the sentence above the diagram that the bottom layer of rock is the oldest.