Question

1. the smallest living things, as well as, all living things are made of ________.
2. the ________ is the name for the double - layered sheet that makes up the cell membrane.
3. a membrane that allows some substances to pass through it while preventing others from passing through it, is called a ______ ______ membrane.
4. the ______ ______ model is the term used to describe the appearance of the cell membrane which has moving proteins within the lipid bilayer.

Explanation:

Question 17

All living organisms, including the smallest ones like bacteria, are composed of cells. The cell is the basic unit of life.

The cell membrane is made up of a double - layered sheet of phospholipids, and this double - layered structure is called the lipid bilayer.

A membrane that is selective in allowing substances to pass through, letting some through and blocking others, is known as a selectively permeable membrane.

Answer:

cells

Question 18