AQA GCSE Biology Biology Paper 2 (Foundation), June 2025: Question 3

✅ Correct Answers

03.1: testis / testes / testicle(s) [1 mark]

03.2: [2 marks]

• Cell A = 46 (1 mark)
• Cell D = 23 (1 mark)

💡 Key Knowledge

• Meiosis produces gametes (sex cells) with half the normal number of chromosomes.
• Normal human body cells are diploid (23 pairs = 46 chromosomes). Cell A is an un-divided parent cell, so it has 46 chromosomes.
• Sperm and egg cells are haploid (single set = 23 chromosomes). Cells D, E, F, and G are gametes with 23 chromosomes each.

🧠 Exam Technique

Carefully count the cell divisions shown in Figure 5:

• Cell division 1 separates homologous pairs.
• Cell division 2 separates chromatids, resulting in 4 genetically different haploid cells.
• Mark scheme backup: If a student confused replicated chromatids and wrote A = 92 and D = 46, examiners awarded a partial compensation mark (1 mark).

❌ Common Errors

• Writing "scrotum" or "penis" instead of testes for where sperm are made.
• Mixing up chromosome numbers: giving 23 pairs (meaning 46) for gamete cell D.

✅ Correct Answers

03.3: fertilisation [1 mark]

03.4: Pollen [1 mark]

03.5: Mitosis [1 mark]

💡 Key Knowledge

• Fertilisation: Fusion of male and female gamete nuclei to restore the full diploid chromosome number.
• Plant Gametes:
  • Male gamete = pollen grain
  • Female gamete = ovule / egg cell
• Runners: Formed by mitosis. Asexual reproduction involves only mitosis, producing genetically identical offspring (clones).

❌ Common Errors

• Ticking ovum in 03.4: Ovum is female, but the question explicitly asks for the male gamete.
• Ticking binary fission in 03.5: Binary fission happens in bacteria (prokaryotes), never multicellular plants!

🧠 Exam Technique

Whenever a question mentions growth, repair, or asexual reproduction in plants or animals, the cell division process is almost always mitosis.

✅ Correct Answers (Tick TWO)

• ☑ Sugar [1 mark]
• ☑ Water [1 mark]

💡 Key Knowledge

• Runners contain vascular bundles (xylem and phloem).
• Phloem transports dissolved sugars (sucrose) made by photosynthesis from the parent leaves to the developing offspring for respiration and building cell walls.
• Xylem transports water and dissolved mineral ions absorbed by the parent's roots.

✅ Correct Answers

03.7 Advantage of Sexual (Any ONE): [1 mark]

• Produces genetic variation in offspring
• Offspring not all wiped out by a single disease / pathogen
• Seeds/fruits can be dispersed to colonise new areas
• Reduced competition between parent and offspring (if dispersed)
• Allows adaptation to changing environments / enables evolution

03.8 Advantage of Asexual (Any ONE): [1 mark]

• Fast / rapid process
• Only one parent needed (no mate/pollinator required)
• Offspring are genetically identical (preserves successful traits)
• Offspring receive water / nutrients directly from the parent plant
• Requires less energy

🧠 Exam Technique

Be specific and avoid vague statements:

• For sexual reproduction, do not just write "diversity". Use the precise specification term: genetic variation.
• For asexual reproduction, stating "only one parent needed" or "does not rely on pollinators/bees" are quick, bullet-proof marks.
• Ensure your answer matches the correct mode: don't accidentally give an advantage of asexual when answering 03.7!

❌ What Students Often Get Wrong

• Vague claims: Saying "it is easier" or "it is better" will score 0 marks. You must state why (e.g., "less energy needed").
• Confusing seeds with runners: Seeds arise from sexual reproduction (flowers); runners are vegetative asexual stems.