What to draw and how to start
Draw an irregular rounded shape for the cell membrane: animal cells do not have a fixed rectangular outline. Inside, draw a large circle slightly off-centre for the nucleus. The space between the nucleus and the cell membrane is the cytoplasm.
Add several small bean-shaped structures scattered through the cytoplasm for the mitochondria. Tiny dots represent ribosomes. For Extended tier, draw a network of folded membranes near the nucleus for the rough endoplasmic reticulum, with ribosomes on its surface.
Structure-to-function links
The cell membrane controls which substances enter and leave the cell. It is partially permeable, allowing water and small molecules through while blocking larger particles.
The nucleus contains the genetic material (DNA) and controls cell activities. The cytoplasm is a jelly-like substance where most chemical reactions take place. Mitochondria are the site of aerobic respiration, releasing energy from glucose. Ribosomes are the site of protein synthesis.
Labelling rules for exam diagrams
Use a ruler for every label line. Lines must touch the structure they name and must not cross each other. Write the label horizontally at the end of the line. Never use arrows: a straight line with a touch-point is what examiners expect.
If the question says "draw and label", you must include the diagram and the labels. If it says "label the diagram", the diagram is already provided and you add labels only. Misreading this instruction is a common reason students waste time.
What makes an animal cell different from a plant cell
An animal cell has no cell wall, no large central vacuole and no chloroplasts. Examiners often ask students to state which structures are present in one cell type but not the other. If you draw a rigid rectangular boundary or add chloroplasts, the diagram is no longer an animal cell.