Cell Structure and Function Quiz

What is the basic unit of life in all living organisms?

• Organelle

• Atom

• Cell

• Tissue

Answer explanation

The basic unit of life in all living organisms is the cell. Cells are the smallest structural and functional units, making them essential for all biological processes.

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NGSS.MS-LS1-1

NGSS.MS-LS1-2

Which part of the cell contains genetic material and controls most cell activities?

• Cytoplasm

• Nucleus

• Ribosome

• Lysosome

Answer explanation

The nucleus is the part of the cell that contains genetic material (DNA) and regulates most cell activities, including growth, metabolism, and reproduction. Other options like cytoplasm, ribosome, and lysosome do not serve this primary function.

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NGSS.MS-LS1-2

What is the function of the cell membrane?

• Produces proteins for the cell

• Converts sunlight into energy

• Controls what enters and exits the cell

• Packages and ships materials inside the cell

Answer explanation

The cell membrane functions primarily to control what enters and exits the cell, maintaining homeostasis and protecting the cell's internal environment. This is essential for the cell's survival and proper functioning.

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NGSS.MS-LS1-2

Which structure is found in plant cells but not in animal cells?

• Mitochondrion

• Chloroplast

• Nucleus

• Cytoskeleton

Answer explanation

Chloroplasts are organelles found in plant cells that enable photosynthesis, converting sunlight into energy. Animal cells do not have chloroplasts, which distinguishes plant cells from animal cells.

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NGSS.MS-LS4-2

What is the function of the mitochondrion?

• Storing water and nutrients

• Generating energy for the cell

• Breaking down waste materials

• Controlling what enters and exits the cell

Answer explanation

The mitochondrion is known as the powerhouse of the cell, as its primary function is to generate energy in the form of ATP through cellular respiration, making 'Generating energy for the cell' the correct choice.

Tags

NGSS.MS-LS1-2

Which term refers to the movement of molecules from a high concentration to a low concentration?

• Osmosis

• Diffusion

• Active transport

• Homeostasis

Answer explanation

Diffusion is the process where molecules move from an area of high concentration to an area of low concentration, seeking to equalize concentrations. This distinguishes it from osmosis, which specifically involves water movement.

What happens to a cell placed in a hypertonic solution?

• It stays the same size

• It swells as water enters the cell

• It shrinks as water leaves the cell

• It bursts due to osmotic pressure

Answer explanation

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

What term describes the diffusion of water across a selectively permeable membrane?

• Isotonic

• Osmosis

• Facilitated diffusion

• Active transport

Answer explanation

Osmosis is the specific term for the diffusion of water across a selectively permeable membrane, allowing water to move from areas of low solute concentration to high solute concentration.

What is the role of aquaporins in a cell?

• Moving ions into the cell

• Allowing water to pass through the membrane

• Breaking down large molecules

• Storing energy for the cell

Answer explanation

Aquaporins are specialized proteins that facilitate the transport of water across cell membranes, allowing water to pass through while preventing the movement of ions and other molecules. Thus, they play a crucial role in maintaining cellular water balance.

Tags

NGSS.MS-LS1-2

When a cell maintains a stable internal environment, it is maintaining _____.

• Osmosis

• Homeostasis

• Active transport

• Diffusion

Answer explanation

When a cell maintains a stable internal environment, it is maintaining homeostasis. This process ensures that conditions such as temperature, pH, and ion concentration remain within a narrow range, essential for cell function.

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NGSS.HS-LS1-3