AQA GCSE Biology Biology Paper 2 (Foundation), June 2022: Question 8

8 marks · Low Demand difficulty · Short Answer

Compare sexual and asexual reproduction, name the male gamete in plants, and interpret a graph showing changes in the mass of DNA per cell during meiosis.

Practise this question

Question

Question 8 begins with Table 4 where students compare sexual and asexual reproduction by ticking rows for fertilisation, passing on genes, and producing genetically identical offspring. Question 08.2 asks to name the male gamete in flowering plants. Below, Figure 12 shows a line graph of mean mass of DNA per cell in arbitrary units against time in hours during meiosis, starting at 4 arbitrary units from 0 to 3 hours, increasing to 8 at 4 hours, remaining at 8 until 5 hours, dropping to 4 at 5 hours, then dropping to 2 at 6 hours and remaining constant until 8 hours. Four multiple-choice questions follow asking when DNA is replicated, which two times cells divide, the mass of DNA in a sperm cell, and the mass in an embryo cell.
Question text

08 There are two types of reproduction:

• sexual reproduction

• asexual reproduction.

08.1 Complete Table 4 to compare sexual reproduction with asexual reproduction.

Write a tick ( ) in the box if the statement is true.

The first row has been completed for you.

[2 marks]

Table 4

Sexual Asexual

reproduction reproduction

Cell division occurs

Fertilisation occurs

Genes are passed on from parent to offspring

Offspring are genetically identical to each other

08.2 Gametes are formed in sexual reproduction.

Name the male gamete formed in flowering plants.

[1 mark]

Cell division by meiosis forms gametes.

Figure 12 shows the mean mass of DNA per cell before, during and after meiosis.

Figure 12

Use information from Figure 12 to answer questions 08.3 to 08.6.

08.3 When is the DNA in the chromosomes being copied?

[1 mark]

Tick ( ) one box.

Between 0 and 3 hours

Between 3 and 4 hours

Between 4 and 5 hours

Between 5 and 6 hours 31

08.4 Cells divide twice during meiosis.

Which two times in Figure 12 show one cell dividing into two cells?

*30* [2 marks]

Tick ( ) two boxes.

3 hours

4 hours

5 hours

6 hours

8 hours

08.5 What is the mean mass of DNA in arbitrary units in a sperm cell?

[1 mark]

Tick ( ) one box.

24 8 16

08.6 What is the mean mass of DNA in arbitrary units in each cell in an embryo?

[1 mark]

Tick ( ) one box.

24 8 16

Mark scheme

Show the mark scheme Mark scheme for Question 8 detailing answers: 08.1 awards 2 marks for ticking sexual only for fertilisation, both for gene transmission, and asexual only for genetically identical offspring (1 mark for 1 or 2 correct rows). 08.2 accepts pollen (grain) (1 mark). 08.3 accepts 'between 3 and 4 hours' (1 mark). 08.4 accepts '5 hours' and '6 hours' (2 marks). 08.5 accepts '2' (1 mark). 08.6 accepts '4' (1 mark). Total 8 marks.

Question 8

AO /

Question Answers Extra information Mark

Spec. Ref.

Sexual Asexual AO1

08.1 reproduction reproduction 2

4.6.1.1

Cell division occurs

Fertilisation occurs

Genes are passed on from

parent to offspring

Offspring are genetically

identical to each other

allow 1 mark for 1 or 2 correct rows

ignore ‘x’ in blank boxes

AO /

Spec. Ref.

08.2 pollen (grain) allow nucleus in pollen (grain) 1 AO1

4.6.1.1

AO /

Spec. Ref.

08.3 between 3 and 4 hours 1 AO2

4.6.1.2

AO /

Spec. Ref.

08.4 5 hours 1 AO2

4.6.1.2

6 hours 1

AO /

Spec. Ref.

08.5 2 1 AO2

4.6.1.2

AO /

Spec. Ref.

08.6 4 1 AO2

4.6.1.2

Total Question 8 8

How to answer it

Reproduction and DNA Mass Changes in Meiosis

📌 What this question tests

This question assesses fundamental knowledge from Topic 6: Inheritance, Variation and Evolution (AQA 4.6.1):

  • Key differences between sexual and asexual reproduction (fertilisation, genetic variation, clone formation).
  • Naming male gametes in flowering plants vs animals.
  • Interpreting a line graph of meiosis: identifying DNA replication (doubling) and cell divisions (halving).
  • Calculating/deducing DNA quantities in haploid gametes compared to diploid body cells (embryo).

Question 08.1: Comparing Types of Reproduction

Complete Table 4 by ticking (✓) true statements [2 marks]

✅ Correct Answer Table

Statement Sexual reproduction Asexual reproduction
Cell division occurs ✓ (given) ✓ (given)
Fertilisation occurs ✓
Genes are passed on from parent to offspring ✓ ✓
Offspring are genetically identical to each other ✓
Mark Scheme: All 3 rows correct = 2 marks; 1 or 2 rows correct = 1 mark. Leaving a box blank or putting an 'x' is accepted as "not ticked".

💡 Key Knowledge

  • Both types pass on genes: all reproduction involves passing genetic material from parent to offspring.
  • Asexual: Only 1 parent, no gametes, no fertilisation, offspring are clones (genetically identical). Uses mitosis.
  • Sexual: Involves fusion of gametes (fertilisation), leads to genetic variation (offspring are non-identical).

❌ Common Errors

  • Ticking only "Sexual" for passing on genes. Remember: Asexual reproduction definitely passes on genes—100% of the single parent's DNA!
  • Ticking "genetically identical" for sexual reproduction. Offspring from sexual reproduction inherit a unique mix of parental alleles.

Question 08.2: Plant Gametes

Name the male gamete formed in flowering plants [1 mark]

✅ Correct Answer

pollen (or pollen grain / pollen nucleus )

1 mark for accurate identification of the male plant gamete.

🧠 Exam Technique

Read carefully whether the question asks for plants or animals:

  • Animals: Sperm (male) & Egg / Ovum (female)
  • Flowering plants: Pollen (male) & Egg / Ovule (female)

❌ Common Errors

  • Writing sperm (incorrect kingdom: animals, not plants).
  • Writing anther or stamen (these are the plant reproductive organs/structures, not the gamete itself).

Question 08.3: DNA Replication in Meiosis

When is the DNA in the chromosomes being copied? [1 mark]

✅ Correct Answer

Between 3 and 4 hours

1 mark for selecting the correct time interval.

💡 Reading the Graph

  • Copying/Replication: The mass of DNA in the cell increases as new DNA is synthesized.
  • Between 0 and 3 hours: DNA mass is constant at 4 units (interphase preparation).
  • Between 3 and 4 hours: DNA mass rises steadily from 4 to 8 arbitrary units. This doubling indicates replication.

Question 08.4: Meiotic Cell Divisions

Which two times in Figure 12 show one cell dividing into two cells? [2 marks]

✅ Correct Answer

  • 5 hours [1 mark]
  • 6 hours [1 mark]
2 marks: 1 mark for each correctly selected time.

🧠 Understanding Meiosis Steps

Meiosis consists of two successive cell divisions:

  • Division 1 (at 5 hours): The cell divides into two daughter cells; DNA per cell drops from 8 to 4 units.
  • Division 2 (at 6 hours): Each cell divides again without replicating DNA; DNA per cell drops from 4 to 2 units.
  • Exam tip: A cell division causes an immediate vertical drop in the DNA mass per cell.

❌ Common Errors

  • Selecting 4 hours (the cell has doubled its DNA but hasn't divided yet).
  • Selecting 8 hours (meiosis finished at 6 hours; between 6 and 8 hours the four gametes simply exist at 2 units).

Questions 08.5 & 08.6: DNA Content in Gametes vs Embryos

Deducing DNA masses from the stages of reproduction [2 marks]

📐 08.5: Mass in a Sperm Cell

Correct Answer: 2 arbitrary units [1 mark]

Step-by-step logic:

  1. Sperm cells are gametes produced at the end of meiosis.
  2. At the end of meiosis (after 6 hours), the graph levels out at 2 units.
  3. Gametes are haploid, containing half the DNA of a normal body cell.

📐 08.6: Mass in an Embryo Cell

Correct Answer: 4 arbitrary units [1 mark]

Step-by-step logic:

  1. An embryo is formed when a sperm fertilises an egg:
    Sperm (2 units) + Egg (2 units) = Zygote/Embryo (4 units)
  2. An embryo consists of normal diploid body cells.
  3. Referring back to the start of the graph (before copying, 0–3 hours), a diploid cell has 4 arbitrary units.

❌ Common Misconceptions (08.6)

  • Picking 8: Confusing normal diploid DNA mass with the temporarily doubled mass (8 units) right before cell division.
  • Picking 2: Forgetting that an embryo is formed by fertilisation, which doubles the haploid gamete number back to the original diploid amount.

Topics

Biology · B6: Inheritance, Variation and Evolution

Question and mark scheme from the AQA GCSE Biology examination, Biology Paper 2 (Foundation), June 2022. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.