AQA GCSE Biology Biology Paper 1 (Foundation), June 2025: Question 1

✅ Correct Answer

Tick: Cytoplasm

💡 Key Knowledge

Under a school light microscope, animal cells typically reveal three main parts:

• Nucleus: Dark central spot containing DNA.
• Cell membrane: The outer boundary.
• Cytoplasm: The jelly-like fluid filling the space between.

❌ Common Errors

Selecting vacuole: Animal cells do not have permanent vacuoles (only plants do). Mitochondria are far too small to see clearly without an electron microscope.

✅ Correct Answer (Any one)

• Chromosome(s)
• Gene(s)
• Also accepted: DNA, allele, genetic material

🧠 Exam Technique: Be Precise

The mark scheme explicitly says "ignore genetic information".

"Information" is an abstract concept, not a physical biological structure or chemical molecule. Always name the actual physical structure: chromosome or DNA.

✅ Correct Answer (Any one)

• (Cell) wall
• (Permanent / large) vacuole
• Chloroplast

❌ Common Trap: Structure vs Substance

• Chloroplast vs Chlorophyll: The chloroplast is the organelle (structure); chlorophyll is the chemical pigment inside it. The mark scheme explicitly states: ignore chlorophyll.
• Cell wall vs Cellulose: Cell wall is the structure; cellulose is what it is made of. The mark scheme explicitly states: ignore cellulose.

✅ Correct Answer

Tick: Water

💡 Key Knowledge

Root hair cells absorb two main substances from the soil:

• Water by osmosis.
• Mineral ions (such as nitrates and magnesium) by active transport.

Plants make their own glucose via photosynthesis—they never absorb glucose or protein from the soil!

✅ Correct Answer (Any one)

• Fertilisation / to fertilise an egg
• To swim to the egg (or join / fuse / reach the egg)
• To carry / provide male genetic material (DNA / chromosomes) to the egg

🧠 Exam Technique

Saying just "to swim" gets 0 marks (the mark scheme notes "ignore swim unqualified"). You must state the purpose of the movement: to reach or fertilise the egg.

✅ Correct Answer

• Nerve cell ➔ Animals [1 mark]
• Xylem cell ➔ Plants [1 mark]

💡 Specialised Cell Roles

• Nerve cell: Long axon to carry electrical impulses throughout an animal's body.
• Xylem cell: Hollow, lignified dead tubes that carry water and mineral ions up a plant stem.

❌ Line Drawing Rule

The command states "Draw one line from each...". If you draw two lines from "Nerve cell" or "Xylem cell", you forfeit the mark for that box completely.

✅ Correct Answer (Tick two)

• ☑ Active transport [1 mark]
• ☑ Diffusion [1 mark]

💡 Key Processes to Remember

• Diffusion: Passive movement of particles from high to low concentration.
• Active Transport: Movement against a concentration gradient using energy from respiration.
• Osmosis: Diffusion of water molecules across a partially permeable membrane.

❌ Distractors Explained

• Mitosis = cell division (making identical body cells).
• Mutation = change in DNA base sequence.
• Respiration = chemical reaction inside cells releasing energy.

💡 Biological Reasoning

• Oxygen: High concentration in blood capillaries, continually consumed inside muscle cells for aerobic respiration. Net movement is only blood ➔ muscle.
• Carbon dioxide: Waste product produced by aerobic respiration in muscle cells. High in muscle, low in blood. Net movement is only muscle ➔ blood.
• Water: Moves in both directions across cell membranes by osmosis depending on hydration and solute levels.

❌ Common Error on Water

Many students wrongly tick "ONLY from muscle cells to blood" because water is a product of respiration. However, water constantly moves dynamically in both directions across the cell membrane to maintain osmotic balance.