AQA GCSE Biology Biology Paper 1 (Foundation), June 2023: Question 4

15 marks · Standard Demand difficulty · Short Answer

Answer questions on the transmission, cell biology, reproduction, blood effects, and statistics of malaria, including calculating survival figures in standard form.

Practise this question

Question

Question text

04 Malaria is caused by a protist.

The protist is passed from one person to another person by mosquitos.

04.1 Which term describes the mosquito?

[1 mark]

Tick ( ) one box.

Bacterium

Gene

Vector

04.2 The malarial protist is a eukaryotic cell.

Figure 2 shows a malarial protist.

Figure 2

Give two features of the malarial protist that show the cell is eukaryotic

and not prokaryotic.

[2 marks]

04.3 Which organism is prokaryotic?

[1 mark]

Tick ( ) one box.

Cow

Grass

Salmonella

04.4 The malarial protist reproduces asexually.

What is a feature of asexual reproduction?

[1 mark]

Tick ( ) one box.

Only one parent is involved.

The offspring show genetic variation.

Two gametes fuse. 16

04.5 Mitosis occurs in the malarial protist during asexual reproduction.

The protist has 14 chromosomes.

How many chromosomes will each new protist cell have after mitosis?

[1 mark]

Tick ( ) one box.

7 14 21 28

04.6 When a person has malaria, the protists destroy red blood cells.

What change would happen in the blood of a person with malaria?

[1 mark]

Tick ( ) one box.

Decreased antibodies

Decreased haemoglobin

Increased plasma

Increased platelets 17

04.7 It is estimated that 210 million people are infected with malaria every year.

Half of these infected people survive the disease.

Calculate how many people would survive the disease in 3 years if the

estimate is correct.

Give your answer in standard form.

[4 marks]

*16* Number of people (in standard form) =

04.8 The spread of malaria can be controlled by using mosquito nets to avoid being bitten.

Describe two other ways that people can reduce the chance of being bitten

by mosquitos.

Do not refer to mosquito nets in your answer.

[2 marks]

04.9 Different types of disease may interact.

Scientists studied how having disorder S interacts with malaria.

The scientists calculated the chance of children with disorder S getting malaria.

Table 4 shows the results.

Table 4

Percentage (%) chance of children

Age in years

with disorder S getting malaria

2 70

4 65

6 50

8 45

Describe the trend shown in Table 4.

Use data from Table 4.

[2 marks]

Mark scheme

Show the mark scheme

Question 4

AO /

Question Answers Extra information Mark

Spec Ref.

04.1 vector 1 AO1

4.3.1.5

AO /

Spec Ref.

04.2 any two from: 2 AO2

4.3.1.5

• (it has) mitochondria

4.1.1.1

if neither mark awarded,

allow 1 mark for protist has

membrane-bound

structures

• (it has a) nucleus allow it does not have a loop

of DNA

• (it has) no plasmids

allow other appropriate features

do not accept (it has) cytoplasm

do not accept (it has) a (cell)

membrane

do not accept it has no cell wall

AO /

Spec Ref.

04.3 Salmonella 1 AO2

4.1.1.1

4.3.1.3

AO /

Spec Ref.

04.4 only one parent is involved 1 AO1

4.3.1.5

4.6.1.1

AO /

Spec Ref.

04.5 14 1 AO2

4.3.1.5 15

4.1.2.2

AO /

Spec Ref.

04.6 decreased haemoglobin 1 AO2

4.3.1.5

4.2.2.3

AO /

Spec Ref.

04.7 allow alternative route AO2

4.3.1.5

allow correct conversion to

standard form at any stage

210 000 000 210 million

allow 1

105 000 000 105 million

105 000 000 × 3 allow 105 million × 3 1

315 000 000 allow 315 million 1

3.15 × 108

AO /

Spec Ref.

04.8 ignore vaccination / anti-malarial AO2

drugs 4.3.1.5

any two from: 2

• wear long(er) sleeves / allow reduce bare skin exposure

clothes

• use insect repellent or allow insect repellent methods

insecticides such as citronella candles

• don’t go out in the evening allow close doors / windows in

the evening

• avoid going to countries /

places with malaria /

mosquitos

• destroy breeding grounds allow methods of destroying

breeding grounds such as drain

water holes

• release sterile male

mosquitos

allow other correct suggestions

AO /

Spec Ref.

04.9 percentage / chance (of getting do not accept percentage / 1 AO3

malaria) decreases (with age) chance of having disorder S 4.2.2.5

decreases with age 4.3.1.5

correct use of data such as two 1

pairs of data from Table 4

allow use of processed data

Total Question 4 15

How to answer it

Malaria: Pathogens, Cell Biology & Disease Control

What this question tests

Communicable diseases & vectors: Understanding how the malarial protist is spread by mosquitos and strategies to disrupt transmission.
Eukaryotes vs prokaryotes: Distinguishing cellular features (e.g., nucleus, mitochondria, absence of plasmids) across cell types.
Cell division & reproduction: Asexual reproduction via mitosis and chromosome conservation.
Pathology & blood cells: The functional effect of destroying red blood cells (loss of haemoglobin).
Maths in Biology: Converting large population figures, performing multi-step operations, and writing numbers in standard form (A × 10ⁿ).
Data analysis: Reading numerical trends from tables and quoting paired values with correct units.

Question 04.1 • AO1 (1 mark)

Malaria Transmission Vector

Identifying the role of the mosquito in the transmission of the malarial protist

✅ Correct Answer

Vector [1 mark]

💡 Key Knowledge

A vector is an organism that carries and passes a pathogen from one host to another without being infected with the disease itself.

Award 1 mark for ticking the "Vector" box only.

Question 04.2 • AO2 (2 marks)

Eukaryotic vs Prokaryotic Structures

Identifying cellular features shown in Figure 2 that confirm the protist is eukaryotic

✅ Correct Answers (any two)

(It has) mitochondria
(It has a) nucleus
(It has) no plasmids

Also allowed: "has membrane-bound structures" (1 mark max if neither specific mark given), or "does not have a loop of DNA".

❌ Common Errors

Cytoplasm: Both prokaryotes and eukaryotes have cytoplasm.
Cell membrane: Present in all cellular organisms.
"Has no cell wall": Incorrect logic; some eukaryotes (plants/fungi) have walls, and animal cells lack them, but this alone does not separate them from all prokaryotes.

1 mark per valid structural feature, up to a maximum of 2 marks.

Question 04.3 • AO2 (1 mark)

Identifying a Prokaryotic Organism

Classifying common organisms into cellular types

✅ Correct Answer

Salmonella [1 mark]

💡 Key Knowledge

Cow: Eukaryote (Animal kingdom)
Grass: Eukaryote (Plant kingdom)
Salmonella: Prokaryote (Bacterium)

Award 1 mark for selecting Salmonella.

Questions 04.4 & 04.5 • AO1 & AO2 (2 marks)

Asexual Reproduction and Mitosis

Features of asexual reproduction and chromosome number after mitosis

✅ Correct Answers

04.4: Only one parent is involved [1 mark]

04.5: 14 [1 mark]

🧠 Exam Technique: Mitosis vs Meiosis

Mitosis produces identical clones. The chromosome number stays exactly the same (14 → 14).

Students who incorrectly ticked 7 confused mitosis with meiosis (which halves chromosome numbers to make gametes).

04.4: 1 mark for single parent; 04.5: 1 mark for identifying chromosome number remains 14.

Question 04.6 • AO2 (1 mark)

Pathology of Malaria: Red Blood Cells

Deducing the physiological consequence of destroying red blood cells

✅ Correct Answer

Decreased haemoglobin [1 mark]

💡 Key Knowledge

Red blood cells are packed with haemoglobin, the iron-containing protein that binds to oxygen. If the protist lyses (bursts) red blood cells, total haemoglobin in the circulation drops, leading to severe anaemia and fatigue.

Award 1 mark for "Decreased haemoglobin".

Question 04.7 • AO2 (4 marks)

Multi-Step Calculation & Standard Form

Calculating survivors over 3 years and converting to standard form

📐 Step-by-Step Calculation

Step 1: Calculate the number of people who survive each year
Half of the infected people survive:
210,000,000 ÷ 2 = 105,000,000 (or 105 million) [1 mark]
Step 2: Multiply by 3 years
105,000,000 × 3 = 315,000,000 (or 315 million) [1 mark for calculation step, 1 mark for value]
Step 3: Convert to standard form (A × 10ⁿ, where 1 ≤ A < 10)
Move the decimal point 8 places to the left:
315,000,000 = 3.15 × 10⁸ [1 mark]

✅ Final Answer

3.15 × 10⁸

❌ Common Calculation Traps

Forgetting to convert to standard form at the end (stops at 315,000,000).
Incorrect index notation: writing 31.5 × 10⁷ or 0.315 × 10⁹ (the leading number must be between 1 and 10).
Forgetting to multiply by 3 years.

Full 4 marks awarded for 3.15 × 10⁸ even if working is minimal. If final answer is wrong, marks are awarded for intermediate steps shown.

Question 04.8 • AO2 (2 marks)

Controlling the Spread of Malaria

Preventing mosquito bites without using mosquito nets

✅ Correct Suggestions (any two)

Wear long sleeves / long trousers (cover skin).
Use insect repellent or insecticides (e.g. citronella sprays/candles).
Avoid going outside during the evening / dusk / dawn when mosquitos feed.
Close windows and doors in the evening / fit window screens.
Avoid travelling to areas/countries with high malaria risk.
Destroy mosquito breeding grounds (e.g., drain standing water / swamps).
Release sterile male mosquitos to crash the population.

❌ Examiner Warning: Read the Restriction

The prompt explicitly says: "Do not refer to mosquito nets in your answer."

Also, ignore vaccination or anti-malarial drugs here—these treat or prevent the parasite surviving in the blood, but they do not stop a person from being bitten.

1 mark for each valid distinct method (maximum 2 marks).

Question 04.9 • AO3 (2 marks)

Data Analysis: Trend and Table Evidence

Describing the relationship between age and the chance of getting malaria

✅ Model Answer

1. Describe the trend:
As age increases, the percentage / chance of children with disorder S getting malaria decreases. [1 mark]

2. Quote paired data from Table 4:
At age 2, the chance is 70%, which drops to 45% by age 8. [1 mark]

🧠 Exam Technique: "Describe trend and use data"

Trend statement: State both variables and direction (e.g., "As X increases, Y decreases").
Data evidence: Always quote two complete pairs of coordinates (both the Age AND the Percentage at two different points) or state a calculated difference (e.g., "decreases by 25% from age 2 to age 8").
Careful reading: Do NOT write "the chance of having disorder S decreases". The children already have disorder S!

1 mark for trend; 1 mark for correct paired data / manipulated difference with correct units (%).

Topics

Biology · B1: Cell Biology · B2: Organisation · B3: Infection and Response · B6: Inheritance, Variation and Evolution

Question and mark scheme from the AQA GCSE Biology examination, Biology Paper 1 (Foundation), June 2023. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.