Which model did scientists develop to describe the cell membrane?

• a. phospholipid model

• b. dynamic model

• c. fluid mosaic model

• d. transport model

Which word best describes the structure of the cell membrane?

• layered

• rigid

• impermeable

• nonpolar

What is a phospholipid composed of?

• a. a polar head and a nonpolar tail

• b. a nonpolar head and a polar tail

• c. a polar head and tail

• d. a nonpolar head and tail

Which phrase best describes the property of selective permeability?

• a. some molecules pass

• b. all ions pass

• c. large molecules pass

• d. all molecules pass

A ligand produces a response in a cell if it finds the right kind of

• carbohydrate

• hormone

• membrane

• receptor

Which phrase best describes passive transport?

• a. requires transport proteins

• b. requires no energy from the cell

• c. requires an isotonic solution

• d. requires facilitation by enzymes

Water moves into a cell when the solution surrounding the cell is

• hypertonic

• hypotonic

• isotonic

• concentrated

What is the term for the diffusion of water across a semipermeable membrane?

• osmosis

• equilibrium

• transport

• isotonic

The movement of molecules down a concentration gradient through transport proteins in the cell membrane is a type of

• a. selective transport.

• b. osmosis.

• c. energy expenditure.

• d. facilitated diffusion.

The difference in the concentration of dissolved particles from one location to another is called a

• a. concentration gradient.

• b. concentrated solution

• c. saline solution.

• d. dynamic gradient.