Unit 3.2

Multiple Choice

The cell membrane is selectively permeable. What does that mean?

• It means the cell membrane only allows water to pass through.
• It means the cell membrane allows some substances to pass while restricting others.
• It means the cell membrane allows all substances to pass freely.
• It means the cell membrane is completely impermeable.

Multiple Choice

Oxygen, food molecules, and waste products all must pass through the...

• cell wall
• nucleus
• cytoplasm
• cell membrane

Multiple Choice

What is the main method by which small molecules move across the cell membrane?

• Passive diffusion
• photosynthesis

• Active transport
• Endocytosis

Multiple Choice

Define diffusion.

• Diffusion is the process of particles moving randomly without any concentration gradient.
• Diffusion refers to the mixing of two substances in equal proportions.
• Diffusion is the transfer of energy from one particle to another.
• Diffusion is the movement of particles from an area of higher concentration to an area of lower concentration.

Multiple Choice

Which is an example of diffusion?

• The spreading of food coloring in water.
• The evaporation of a puddle on a sunny day.
• The melting of ice into water.
• The mixing of two gases in a closed container.

Multiple Choice

What is the diffusion of water called?

• Evaporation
• Osmosis
• Diffusion
• Filtration

Multiple Choice

Why do cells depend on osmosis?

• Cells depend on osmosis to regulate water balance and maintain proper function.
• Cells rely on osmosis to absorb nutrients efficiently.
• Cells use osmosis to generate energy.
• Osmosis helps cells to divide and replicate.

Multiple Choice

Define osmosis.

• Osmosis is the movement of solutes across a semipermeable membrane.
• Osmosis is the diffusion of gases in a liquid.
• Osmosis is the process of energy production in cells.
• Osmosis is the movement of water molecules (across a semipermeable membrane) from an area of high concentration to an area of low concentration.

Multiple Choice

Which is an example of osmosis?

• Sugar being absorbed by the bloodstream.
• Water moving into a plant root from the soil.
• Salt dissolving in water.
• Air moving into a balloon.

Multiple Choice

Define active transport.

• Active transport is the passive movement of water across a membrane.
• Active transport is the movement of molecules with their concentration gradient without energy.
• Active transport is the movement of molecules across a cell membrane from an area of low concentration to an area of high concentration, requiring energy.

• Active transport refers to the diffusion of gases in and out of cells.

Multiple Choice

What substances require active transport?

• Lipids and fats
• Small nonpolar molecules
• Calcium, sodium, potassium

• Water and oxygen

Multiple Choice

What an example of active transport?

• Endocytosis
• Facilitated diffusion
• Engulfing

• Osmosis