A student looks at a plant cell and an animal cell under a microscope. The student says: 'Both cells must be making proteins, so both cells must contain ribosomes.' Explain why the student is correct that both cells contain ribosomes, and explain how two other structures that are present in both cell types allow the cells to carry out their life processes.

AQA A-Level Biology (7402) — 3.2.1 Cell Structure · Explain · 5 marks · View as Markdown

Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).

Model answer (5 marks)

Ribosomes are the sites of protein synthesis; any cell that is synthesising proteins must therefore contain ribosomes.

The cell membrane is present in both plant and animal cells. It controls the passage of substances into and out of the cell, allowing the cell to maintain its internal environment.

Mitochondria are also found in both cell types. They are the sites of aerobic respiration, producing ATP that supplies energy for the cell’s life processes.

Examiner tips

  • Use the exact phrases ‘site of protein synthesis’ and ‘site of aerobic respiration’.
  • Show the link between ribosomes and protein synthesis, and between the membrane/mitochondria and their functions.
  • Keep each point brief and to the point.

Mark scheme (5 marks)

  1. Ribosomes are the site of protein synthesis, so any cell making proteins must have ribosomes
  2. The cell membrane is found in both cell types
  3. The cell membrane controls what substances enter and leave the cell
  4. The mitochondria are found in both cell types
  5. Mitochondria are the site of aerobic respiration, releasing energy for the cell

Key terms in this question

ribosomes

Related

More Cell Structure questions

▶ Try answering this question with AI marking (free) →