Cell Signaling Quiz

What is the term for a specific chemical signal released from one cell that binds to a receptor on another cell?

• Target cell

• Receptor

• Ligand

• Synapse

A cell will only respond to a specific ligand if it has which of the following?

• The correct secreting cell nearby

• A cell surface receptor with a complementary shape to the ligand

• A very high concentration of the ligand around it

• A cell wall made of cellulose

Which sequence correctly outlines the three main stages of a cell signalling pathway?

• Binding, Transport, Secretion

• Transport, Secretion, Binding

• Secretion, Binding, Transport

• Secretion, Transport, Binding

Which statement best describes facilitated diffusion?

• The net movement of water across a partially permeable membrane.

• The movement of substances against a concentration gradient using ATP.

• The passive movement of molecules down a concentration gradient via specific protein channels or carriers.

• The movement of small, non-polar molecules directly across the phospholipid bilayer.

Osmosis is the net movement of water molecules from a region of ______ to a region of ______.

• lower water potential; higher water potential

• higher water potential; lower water potential

• negative water potential; zero water potential

• low solute concentration; high solute concentration

What is the water potential ($Ψ$) of pure water defined as?

• 100 kPa

• 0 kPa

• -10 kPa

• A positive value

What happens to a red blood cell when it is placed in pure water?

• It shrivels and undergoes crenation.

• It swells and bursts in a process called haemolysis.

• It becomes turgid but does not burst.

• It undergoes plasmolysis.

A plant cell is placed in a solution with a very low water potential. What is the likely outcome?

• The cell will become turgid.

• The cell will undergo haemolysis.

• The cell membrane will pull away from the cell wall as the cell becomes plasmolysed.

• The cell wall will dissolve.

Which of these molecules would most likely move across a cell membrane by simple diffusion?

• Glucose

• A sodium ion (Na⁺)

• Oxygen (O₂)

• Water (H₂O)

Why does a plant cell not burst when placed in a solution with a higher water potential, unlike an animal cell?

• Its membrane is impermeable to water.

• It actively pumps water out as fast as it enters.

• Its strong cellulose cell wall withstands the pressure.

• Its vacuole shrinks to make space for the incoming water.