1. The cell membrane is , which means that some substances can pass through it but others can't. 2. In diffusion, molecules move from an area of concentration to an area of concentration.
3. Two ways of moving things into and out of cells that do NOT need energy are and . Moving materials through a cell membrane without using energy is called transportation.
4. List two ways that the cell moves things by active transport.
a. Active transport requires energy from the cell.
b.

d

explanation:

the higher the instrument the better

the answer is true when observing or determining population size, a direct observation is use, in which each organism is counted in a population or in an area. one benefit of this measure is that you get the exact population count but it will take a long time to  determine  the  size  of a  population.

answer;

-chlorine

explanation;

-toxic industrial chemicals are industrial chemicals that are manufactured, stored, transported, and used throughout the world. toxic industrial chemicals can be in the gas, liquid, or solid state.

-they can be chemical hazards (e.g., carcinogens, reproductive hazards, corrosives, or agents that affect the lungs or blood) or physical hazards (e.g., flammable, combustible, explosive, or reactive).