Animal and plant cells: Most animal cells have the following parts:

The idea

Most animal cells share a common set of parts, each with a job. The nucleus contains DNA and controls the cell. The cytoplasm is where most chemical reactions happen. The cell membrane controls what enters and leaves. Mitochondria are the site of aerobic respiration, releasing energy. Ribosomes are the site of protein synthesis. Animal cells do not have a cell wall or chloroplasts, and they store carbohydrate as glycogen. For example, a liver cell has many mitochondria and ribosomes because it is metabolically active. When you describe an animal cell, name each part and give its function, and be ready to compare it with a plant cell.

What earns the marks

• The nucleus contains the genetic material and controls the cell's activities.
• The cytoplasm is where most of the cell's chemical reactions take place.
• The cell membrane controls the movement of substances into and out of the cell.
• Mitochondria are the site of aerobic respiration, releasing energy for the cell.
• Ribosomes are the site of protein synthesis.
• Animal cells lack a cell wall and chloroplasts, and store carbohydrate as glycogen.

Common mistakes and how to put them right

• Including a cell wall or chloroplasts in an animal cell.

  Put it right by listing only the parts an animal cell actually has.

• Writing that the cytoplasm is just 'jelly' with no role.

  Put it right by stating it is where chemical reactions occur.

• Confusing ribosomes with mitochondria.

  Put it right by linking ribosomes to protein synthesis and mitochondria to respiration.

Exam tips

• Learn the animal cell parts as a list with a function for each, so you can answer either a labelling or an explanation question.
• If asked to compare with a plant cell, state clearly which parts are present in one but not the other.
• Use precise terms such as 'partially permeable' for the cell membrane rather than 'lets things through'.