Cell membrane, passive and active transport

Which component of the cell membrane strengthens its structure and maintains its fluidity?

• A

• B

• C

• D

Identify the molecule in the provided image that serves as an identification tag for cells.

• A

• B

• C

• D

Which of the following best describes the arrangement of phospholipids in the cell membrane?

• Heads face inward, tails face outward.

• Heads face outward, tails face inward

• Heads and tails are randomly arranged.

• Heads and tails form a single layer.

What term describes the cell membrane's ability to allow only some substances to cross?

• Permeability

• Mosaic model

• Selective permeability

• Fluidity

What happens when a signal molecule binds to a receptor in the cell membrane?

• The signal molecule enters the cell and interacts with DNA

• The receptor changes shape, triggering a cellular response.

• The receptor is deactivated, stopping all signals.

• The signal molecule is destroyed by enzymes.

What is the main difference between diffusion and osmosis?

• Diffusion refers to the movement of water molecules, while osmosis refers to solutes.

• Osmosis refers to the movement of water molecules, while diffusion refers to solutes.

• Diffusion and osmosis both move only solutes.

• Diffusion and osmosis require energy to occur.

Which statement correctly describes the movement of molecules during diffusion?

• Molecules move from low concentration to high concentration

• Molecules move randomly without regard to concentration gradients.

• Molecules stop moving once equilibrium is reached.

• Molecules move from high concentration to low concentration.

What happens to a red blood cell placed in a hypertonic solution?

• It shrivels and shrinks.

• It swells and bursts.

• It remains the same size.

• It divides into two cells.

What type of solution causes a plant cell to become turgid (swollen)?

• Isotonic solution

• Hypertonic solution

• Hypotonic solution

• None of the above

What is facilitated diffusion?

• The diffusion of water molecules only.

• The movement of molecules through the lipid bilayer without energy.

• The use of transport proteins to move molecules across the cell membrane without energy.

• The use of ATP to actively move molecules across the membrane.