AQA GCSE Biology Biology Paper 2 (Higher), June 2022: Question 1

8 marks · Low Demand difficulty · Short Answer

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

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Question

Question text

01 There are two types of reproduction:

• sexual reproduction

• asexual reproduction.

01.1 Complete Table 1 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 1

Sexual Asexual

reproduction reproduction

Cell division occurs

Fertilisation occurs

Genes are passed on from parent to offspring

Offspring are genetically identical to each other

01.2 Gametes are formed in sexual reproduction.

Name the male gamete formed in flowering plants.

[1 mark]

Cell division by meiosis forms gametes.

Figure 1 shows the mean mass of DNA per cell before, during and after meiosis.

Figure 1

Use information from Figure 1 to answer questions 01.3 to 01.6.

01.3 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 5

01.4 Cells divide twice during meiosis.

Which two times in Figure 1 show one cell dividing into two cells?

*04* [2 marks]

Tick ( ) two boxes.

3 hours

4 hours

5 hours

6 hours

8 hours

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

[1 mark]

Tick ( ) one box.

24 8 16

01.6 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

Question 1

AO /

Question Answers Extra information Mark

Spec. Ref.

Sexual Asexual AO1

01.1 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.

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

4.6.1.1

AO /

Spec. Ref.

01.3 between 3 and 4 hours 1 AO2

4.6.1.2

AO /

Spec. Ref.

01.4 5 hours 1 AO2

4.6.1.2

6 hours 1

AO /

Spec. Ref.

01.5 2 1 AO2

4.6.1.2

AO /

Spec. Ref.

01.6 4 1 AO2

4.6.1.2

Total Question 1 8

How to answer it

Reproduction Types & DNA Changes During Meiosis

📌 What this question tests

This question assesses your understanding of sexual vs asexual reproduction, plant gametes, and interpreting graphical data showing changes in DNA mass during meiosis. You need to identify key stages of cell division: DNA replication, two successive divisions, and the resulting haploid vs diploid mass of DNA in gametes and embryos.

Question 01.1

Comparing Sexual and Asexual Reproduction

Table Completion [2 marks]

✅ Correct Answer (Completed Table 1)

Feature	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	—	✓

🧠 Exam Technique & Mark Breakdown

2 marks: All 3 rows completed completely correctly.
1 mark: 1 or 2 rows completed correctly.
Top Tip: Leave incorrect boxes completely blank, or write a neat cross. The mark scheme explicitly states: "ignore 'x' in blank boxes".
Notice that genes are always passed on in both types of reproduction—asexual reproduction does not mean no genes are inherited!

💡 Key Knowledge

Sexual reproduction: Involves two parents, fusion of gametes (fertilisation), leads to genetic variation (offspring are non-identical).
Asexual reproduction: Involves one parent, no gametes/fertilisation, relies on mitosis, produces genetically identical offspring (clones).

❌ Common Errors

Ticking only "Sexual reproduction" for genes are passed on, mistakenly thinking asexual reproduction doesn't involve DNA/genes.
Ticking genetically identical for sexual reproduction (identical twins are a rare exception; the biological principle is that sexual reproduction produces variation).

Question 01.2

Male Gametes in Flowering Plants

Recall Question [1 mark]

✅ Correct Answer

pollen (or pollen grain)

Also acceptable: nucleus in pollen (grain).

❌ Common Errors & Examiner Traps

"Sperm" — Sperm is the male gamete in animals, not flowering plants!
"Anther" or "Stamen" — These are the organ/structure producing the gamete, not the gamete itself.
Female equivalent check: The female gamete in plants is the ovule (or egg cell).

📈 Understanding Figure 1: DNA Mass in Meiosis

Graph Analysis (Mean mass of DNA per cell vs Time):

0 to 3 hours (mass = 4 units): Normal body (diploid) cell prior to division.
3 to 4 hours (mass rises from 4 to 8 units): DNA replication (chromosomes are copied).
4 to 5 hours (mass = 8 units): Cell prepares to undergo the first division.
At 5 hours (mass drops sharply from 8 to 4 units): First meiotic division (1 cell → 2 daughter cells).
At 6 hours (mass drops sharply from 4 to 2 units): Second meiotic division (2 cells → 4 haploid gametes).
6 to 8 hours (mass stays at 2 units): Gametes formed (contain half the original DNA mass).

Question 01.3

DNA Replication Timing

Data Interpretation [1 mark]

✅ Correct Answer

Tick box: Between 3 and 4 hours

🧠 Exam Technique

"Copied" means DNA is doubling (synthesised). On the graph, look specifically for where the line has a positive slope (increases). The line only rises between 3 and 4 hours (from 4 to 8 units).

Question 01.4

Identifying Division Points

Tick Two Boxes [2 marks]

✅ Correct Answer

✓ 5 hours
✓ 6 hours

1 mark for each correct box ticked. Maximum 2 marks.

💡 Key Knowledge

When a cell splits into two, its total DNA is shared equally between the two new cells. Therefore, on a graph of mean mass per cell, each division is shown by an immediate vertical drop:

Drop 1: 5 hours (8 → 4 arbitrary units)
Drop 2: 6 hours (4 → 2 arbitrary units)

Questions 01.5 & 01.6

DNA Content in Gametes vs Embryos

Multiple Choice & Deduction [2 marks total]

📐 Part 01.5: Sperm Cell (Gamete) [1 mark]

Correct Box: 2

Step-by-step reasoning:

Meiosis produces gametes (sperm cells).
At the end of meiosis (hour 6–8), the DNA mass per cell stabilizes at 2 units.
Gametes are haploid (half the DNA of the original diploid parent cell, which had 4 units: 4 ÷ 2 = 2).

📐 Part 01.6: Embryo Cell [1 mark]

Correct Box: 4

Step-by-step reasoning:

An embryo is formed when two gametes fuse during fertilisation (sperm + egg).
Sperm cell DNA (2) + Egg cell DNA (2) = 4 arbitrary units.
This restores the full diploid chromosome/DNA complement.

❌ Common Misconception: Choosing 8 or 16 for the Embryo

Many students see that replication peaked at 8 and select 8 or 16 for the embryo. Remember: an embryo is made of normal diploid body cells dividing by mitosis. The starting amount of DNA in a normal diploid cell before copying is 4, not 8!

Topics

Biology · B6: Inheritance, Variation and Evolution

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