Cell Transport EOC

What is the main function of the plasma membrane in a cell?

• To synthesize proteins

• To control what enters and leaves the cell

• To produce energy

• To store genetic information

Answer explanation

The plasma membrane's main function is to control what enters and leaves the cell, maintaining homeostasis and protecting the cell's internal environment. This selective permeability is crucial for cell function.

Tags

NGSS.MS-LS1-2

Which type of transport requires no energy from the cell?

• Endocytosis

• Passive transport

• Exocytosis

• Active transport

Answer explanation

Passive transport is the movement of substances across a cell membrane without the use of energy. Unlike active transport, which requires energy, passive transport relies on concentration gradients.

What is the process called when water moves across a semi-permeable membrane?

• Diffusion

• Osmosis

• Facilitated diffusion

• Active transport

Answer explanation

The process when water moves across a semi-permeable membrane is called osmosis. It specifically refers to the movement of water from an area of lower solute concentration to an area of higher solute concentration.

Which of the following is NOT a type of passive transport?

• Facilitated diffusion

• Simple diffusion

• Pump transport

• Osmosis

Answer explanation

Pump transport is NOT a type of passive transport; it requires energy to move substances against their concentration gradient. In contrast, facilitated diffusion, simple diffusion, and osmosis are all passive processes that do not require energy.

What is the term for the movement of particles from an area of higher concentration to an area of lower concentration?

• Exocytosis

• Endocytosis

• Active transport

• Diffusion

Answer explanation

The term for the movement of particles from an area of higher concentration to an area of lower concentration is diffusion. This process occurs naturally and does not require energy, unlike active transport.

In which type of solution does a cell maintain its normal shape?

• Hypertonic solution

• Isotonic solution

• Concentrated solution

• Hypotonic solution

Answer explanation

A cell maintains its normal shape in an isotonic solution because the concentration of solutes is equal inside and outside the cell, preventing net movement of water and maintaining equilibrium.

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

• It remains the same

• It swells and bursts

• It doubles in size

• It shrinks

Answer explanation

In a hypertonic solution, the concentration of solutes outside the red blood cell is higher than inside. This causes water to move out of the cell, leading to its shrinkage.

Tags

NGSS.HS-LS1-3

Which type of transport protein forms pores in the membrane?

• Channel proteins

• Carrier proteins

• Receptor proteins

• Pump proteins

Answer explanation

Channel proteins form pores in the membrane, allowing specific ions or molecules to pass through. Unlike carrier proteins, which change shape to transport substances, channel proteins provide a direct pathway.

What is facilitated diffusion?

• Diffusion with the help of transport proteins

• Diffusion without any assistance

• Movement of water across a membrane

• Active transport of ions

Answer explanation

Facilitated diffusion is a process where molecules move across a membrane with the help of transport proteins, making it easier for substances that cannot directly diffuse through the lipid bilayer.

Which of the following molecules can easily diffuse across the cell membrane?

• Glucose

• Oxygen

• Proteins

• Starch

Answer explanation

Oxygen can easily diffuse across the cell membrane due to its small size and nonpolar nature, allowing it to pass through the lipid bilayer. In contrast, glucose, proteins, and starch are larger or polar and require transport mechanisms.