Parts of Plant and Animal Cells

Question 1

A 7th‑grade student builds a model of an animal cell that includes the nucleus, mitochondria, ribosomes, and cell membrane. Which explanation best describes how these parts work together to keep the cell alive?

Accepted Answer

The nucleus stores genetic information, the mitochondria produce energy, ribosomes make proteins, and the cell membrane controls what enters and leaves, allowing the cell to grow, obtain energy, and maintain its internal environment.

Answer

The nucleus creates energy for the cell, the mitochondria store DNA, ribosomes transport materials, and the cell membrane makes proteins, so the cell can move and reproduce.

Answer

The nucleus and mitochondria both produce proteins, ribosomes store genetic material, and the cell membrane provides energy, which together allow the cell to digest food.

Answer

The nucleus controls the cell’s shape, the mitochondria protect the cell from viruses, ribosomes send signals to other cells, and the cell membrane stores waste, keeping the cell healthy.

Question 2

A plant root cell is growing in very dry soil. To stay healthy, the cell must keep enough water inside so it doesn’t collapse. Which organelle best helps the cell meet this need, and why?

Accepted Answer

The large central vacuole – it stores water, keeping the cell turgid and preventing collapse.

Answer

The cell wall – it acts like a barrier that stops water from leaving the cell.

Answer

The mitochondria – they produce energy that powers pumps to move water into the cell.

Answer

The ribosomes – they make proteins that hold water inside the cell.

Question 3

Which description best models how the major organelles of an animal cell work together to produce proteins that the cell needs?

Accepted Answer

The nucleus stores DNA that contains the instructions for proteins; the DNA is transcribed into mRNA, which moves to ribosomes. Ribosomes read the mRNA to assemble amino acids into proteins. The rough endoplasmic reticulum transports the new proteins to the Golgi apparatus, where they are modified, packaged, and sent to the cell membrane for release.

Answer

The nucleus produces the energy needed for protein synthesis; the ribosomes store DNA and directly assemble proteins without mRNA; the Golgi apparatus packages the proteins and sends them back to the nucleus.

Answer

The cell membrane controls protein synthesis; lysosomes create proteins; and the smooth endoplasmic reticulum stores the DNA that directs protein production.

Answer

The mitochondria store DNA that contains the instructions for proteins; the DNA is transcribed into mRNA, which moves to ribosomes. Ribosomes read the mRNA to assemble amino acids into proteins, which are then sent directly to the cell membrane.

Try three questions

A 7th‑grade student builds a model of an animal cell that includes the nucleus, mitochondria, ribosomes, and cell membrane. Which explanation best describes how these parts work together to keep the cell alive?

A plant root cell is growing in very dry soil. To stay healthy, the cell must keep enough water inside so it doesn’t collapse. Which organelle best helps the cell meet this need, and why?

Which description best models how the major organelles of an animal cell work together to produce proteins that the cell needs?

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