The Cell in Its Environment

Water diffusing through a semipermeable membrane is called

• active transport
• osmosis
• facilitated diffusion
• hydrocytosis

Exocytosis occurs when a cell engulf large food particles.

• true
• False

The cell membrane is built of a double layer of ______________

• lipids
• carbohydrates
• proteins
• nucleic acids

Facilitated diffusion moves large particles such as sugars through

• lipid channels
• protein channels
• carbohydrate channels
• water channels

The cell membrane controls the materials that move into and out of a cell.

• true
• False

Passive transport can move molecules from a low to high concentration.

• true
• False

Glucose enters a liver cell through a protein channel. What type of transport is this?

• diffusion
• facilitated diffusion
• osmosis
• active transport

Oxygen moves into a contracting heart muscle cell. What type of transport is this?

• diffusion
• facilitated diffusion
• osmosis
• active transport

A nerve cell uses energy to pump sodium out of its cytoplasm into a sodium-rich environment. What type of transport is this?

• diffusion
• facilitated diffusion
• osmosis
• active transport

Water moves out of the skin cells of a person swimming in a freshwater pond. What type of transport is this?

• diffusion
• facilitated diffusion
• osmosis
• active transport