Cell Transport Unit Test

Which of the following scenarios is an example of osmosis?

• carbohydrates moving in and out of an animal cell

• carbon dioxide moving into the leaf cells of a plant

• water moving into the root cells of a plant

• oxygen moving into the bloodstream from the lungs

What term is used to describe the cell’s maintenance of a stable, internal environment

resulting in balance?

• Homeostasis
• Osmosis
• Mitosis
• Photosynthesis

The structure in the middle is a channel protein.

The function of this protein is to_____.

• Provide structural support to the cell
• Facilitate the transport of substances across the cell membrane
• Synthesize new proteins for the cell
• Regulate the cell's metabolic processes

Cell membranes are composed of a specific type of biomolecule. What biomolecule is shown here that isn't the channel protein that makes up the bilayer.

• Protein

• Phospholipid

• Amino Acid

• Nucleic Acid

Which of the following statements best describes why oxygen diffuses from the lungs

into the blood?

• The diaphragm draws oxygen into the lungs at a rapid speed

• Lung cells contain hemoglobin to transfer gases to the blood

• Red blood cells move one at a time through the capillaries within the lungs

• The concentration of oxygen is greater in the lungs than in the blood therefore the oxygen will

  move from a high concentration to a low concentration

Pure water is always ______________ when compared to any cell.

• tonic

• isotonic

• hypotonic
• hypertonic

Active transport is a way for molecules to move across the cell membrane. When active

transport is used to move molecules, what is required?

• Very small molecules

• ATP energy
• Heat energy
• Osmosis

The diagram shows how carrier

molecules allow passive and active

transport. In the diagram of active

transport, the letter X represents

another molecule. This molecule

provides energy for active transport

but is not needed for passive

transport. Which molecule is most

likely represented by X?

• ATP energy

• Water

• DNA

• Oxygen

The process of “cell eating” is known as_________.

• Osmosis
• Diffusion
• Phagocytosis
• Pinocytosis

The cellular process known as the sodium-potassium pump was discovered

in the 1950’s by Jens Christian Skou, a Danish scientist. This process is a form of

active transport that moves three sodium ions to the outside of a cell for every two potassium

ions that it moves to the inside of the cell. Which of these best explains why energy is needed

for active transport?

• Energy is needed to maintain the concentration gradient of sodium and potassium ions
• Energy is not needed for active transport
• Active transport is a passive process
• Active transport occurs naturally without energy