AQA GCSE Biology Biology Paper 1 (Foundation), November 2021: Question 1

✅ Correct Answer

First box (Left diagram)

The diagram showing many oxygen particles outside the cell, fewer particles inside the cell, and the movement arrow pointing inwards.

💡 Key Knowledge

• Diffusion is the net movement of particles from an area of higher concentration to an area of lower concentration.
• Cells continually use oxygen for aerobic respiration, so oxygen levels inside the cell remain lower than outside, allowing oxygen to diffuse in naturally.

🧠 Exam Technique

Count or compare the density of the dots! Diffusion always points from the "crowded" side (higher concentration) to the "less crowded" side (lower concentration).

❌ Common Errors

Selecting the third diagram (where particles are crowded inside and moving in). That diagram represents movement against a concentration gradient, which is active transport, not diffusion.

✅ Correct Answers

• Plant cells use osmosis to absorb water. [1 mark]
• Plant cells use active transport to absorb mineral ions. [1 mark]
• Active transport moves substances against the concentration gradient and needs energy. [1 mark]

💡 Key Knowledge

• Osmosis: Diffusion of water only across a partially permeable membrane.
• Active Transport: Moves substances from a dilute solution to a more concentrated solution (against the gradient).
• Requires energy from respiration because particles are pushed uphill against their gradient.

❌ Common Errors

• Writing "carbon dioxide" or "light" — these are absorbed by leaves for photosynthesis, not from the soil by roots.
• Confusing osmosis and active transport: remember Osmosis = H₂O (water only).

🧠 Exam Technique

Cross out options from the box as you use them. There are 6 words for 3 gaps, meaning 3 are distractors.

✅ Correct Answers

01.3 Name of cell:

• root hair (cell) [1 mark]

01.4 Adaptation:

• large surface area [1 mark]

💡 Key Knowledge

• The long hair-like extension significantly increases the surface area to volume ratio of the root.
• A larger surface area speeds up the rate of water intake by osmosis and mineral absorption by active transport.
• Lots of mitochondria provide the ATP/energy needed for active transport of minerals.

❌ Common Errors

• 01.3: Writing just "root" or "hair" unqualified scores 0 marks. You must state "root hair" or "root hair cell".
• 01.4: Saying "it is long" without linking it to surface area, or claiming it contains chloroplasts (roots are underground and do not carry out photosynthesis!).

🧠 Exam Technique

Whenever you see an outstretched, folded, or protruding structure in biology (like microvilli or root hairs), the adaptation mark is almost always "large surface area".

✅ Correct Matches

💡 Key Knowledge

• The nucleus contains genetic material (23 chromosomes in humans) needed to create a diploid zygote upon fertilisation.
• The flagellum (tail) whips back and forth to propel the sperm towards the ovum.
• Distractor check: "To release energy" is the role of mitochondria in the midpiece. "To break the outer layer of the egg" is the role of the acrosome (enzymes in the head).

🧠 Exam Technique

Use a ruler to draw straight, clear lines. If you change your mind, completely cross out the incorrect line so the examiner knows which one to mark.

❌ Common Errors

Drawing multiple lines from one feature box to hedge bets. The mark scheme explicitly states: "do not accept more than one line from a box on the left".

✅ Correct Answers

Name of the cell:

• nerve (cell) or neuron / neurone [1 mark]

Feature of the cell (any one):

• long (or has a long axon)
• has branches (or branched endings / dendrites)
• has insulation (allow myelin / fat) [1 mark]

💡 Key Knowledge

• Long axon: Enables electrical impulses to travel long distances across the body quickly without interruption.
• Dendrites (branches): Allow connections to multiple other nerve cells or effector organs.
• Myelin sheath: Insulates the axon to speed up transmission of electrical impulses.

❌ Common Errors

• Writing "brain cell" instead of nerve cell / neuron.
• Overcomplicating the name: specific types like "motor / sensory / relay" are ignored by the mark scheme; keep it simple with "nerve cell" or "neuron".
• Confusing electrical impulses with "messages" or "brain waves" in the explanation.

🧠 Exam Technique

Notice the prompt asks for one feature, not an essay. Naming just one clear structural property (e.g., "it is long") secures the second mark instantly.