AQAGCSEBiologyFoundation2 marksDiagram included
GCSE revision question
Question context
The diagram shows the structure of a typical animal cell highlighting the nucleus, cytoplasm, and cell membrane. Key Idea 1 focuses on cell structure and function.
Question diagram
Calculate the ratio of the nucleus diameter (10 µm) to the cell diameter (50 µm). Give your answer in the form 1 : x.
Show answer, mark scheme and Mentor explanation
Answer and mark-scheme guidance
MP1: Sets up ratio nucleus : cell = 10 : 50 (or 10 ÷ 50)
MP2: Simplifies to 1 : 5 (accept 0.2 or 1/5 as equivalent)
Mentor — AI Tutor
Can you spot the two steps the mark scheme needs?
This question tests whether you can set up the ratio in the correct order and then simplify it to the required form. The mark scheme first gives credit for nucleus : cell = 10 : 50, or for showing 10 ÷ 50. The second mark is for simplifying this to 1 : 5. Equivalent forms such as 0.2 or 1/5 are accepted, but the question asks for the form 1 : x, so 1 : 5 matches that instruction directly.
Quick takeaway: Earn one mark for 10 : 50 and one mark for simplifying to 1 : 5.