AQA GCSE Biology Biology Paper 1 (Foundation), November 2021: Question 9

✅ Correct Answer

Tick the box for: Normal

🧠 Exam Technique

Two methods lead to the correct answer:

• Method 1 (Chart): Find 63 kg on the horizontal axis and trace up to 1.65 m on the vertical axis in Figure 18. The intercept sits safely within the Normal band.
• Method 2 (Table): Table 4 already calculates Person A's BMI as 23.1 kg/m². Standard healthy adult BMI is between 18.5 and 24.9.

📐 Step-by-Step Calculation

1. Identify values from Table 4:
   Mass = 92 kg
   Height = 1.71 m
2. Substitute into formula [Mark 1]:
   BMI = 92 ÷ (1.71)²
3. Calculate intermediate value [Mark 2]:
   (1.71)² = 2.9241
   92 ÷ 2.9241 = 31.46267...
4. Round to 3 significant figures [Mark 3]:
   The 4th figure is 6 (≥ 5), so round up:
   X = 31.5 kg/m²

❌ Common Calculation Errors

• Forgetting to square the height: Calculating 92 ÷ 1.71 = 53.8.
• Incorrect rounding: Writing 31.4 (truncating instead of rounding) or leaving it as 31.46 (4 significant figures instead of 3).
• Calculator order of operations: Entering 92 ÷ 1.71² correctly requires typing 92 ÷ (1.71²) or doing 1.71 × 1.71 first.

✅ Correct Answer (Any TWO of the following)

• As BMI category increases, the number of years living in good health decreases.
• As BMI category increases, the number of years living in bad health increases.
• As BMI category increases, the total life expectancy decreases (e.g. Normal: 19.06 + 4.98 = 24.04 years vs Clinically obese: 13.07 + 10.10 = 23.17 years).

🧠 Exam Technique: "Describe a Pattern"

Use a comparative structure: "The higher the [independent variable], the [higher/lower] the [dependent variable]."

Avoid simply copying raw numbers without stating the overall relationship.

✅ Award-Winning Responses (Need 1 cause + 1 linked economic consequence)

Route 1: Healthcare Burden

• Cost: Increases healthcare costs for the NHS / government / hospitals [1 mark].
• Reason: Due to increased need for medications, treatments, or surgeries for associated conditions (e.g. type 2 diabetes, stroke, joint replacements) [1 mark].

Route 2: Workforce Impact

• Cost: Reduces economic output / lowers productivity / employer pays sick pay [1 mark].
• Reason: More people are unfit for work or require extended sick leave due to obesity-related illness [1 mark].

❌ Common Errors

• Too vague: Saying "It costs money" without naming who pays (the NHS, government, or employers).
• Missing the mechanism: Stating the NHS pays more, but failing to specify why (e.g., to treat diabetes, perform surgery, or pay for prescription drugs).

✅ Acceptable Suggestions (Any ONE)

• Movement/Mobility issues: Difficulty walking, climbing stairs, or exercising.
• Employment impacts: Inability to work or loss of job / income.
• Mental wellbeing: Negative mental health impacts due to chronic pain or isolation.
• Medical dependence: Needing daily pain medications, frequent doctor/physiotherapy appointments, or surgery (e.g. hip/knee replacement).

💡 Key Knowledge

Obesity puts extra mechanical stress on weight-bearing joints (knees and hips), wearing down articular cartilage and leading to osteoarthritis.

✅ Correct Answer (Name ANY TWO)

• Type 2 diabetes (Must state Type 2; diabetes alone is often penalised).
• Coronary heart disease (CHD) / Cardiovascular disease (CVD).
• Heart attack.
• Stroke.
• Atherosclerosis (narrowing/hardening of arteries).
• High blood pressure (hypertension).
• Liver disease / Certain cancers.

❌ Disallowed Answers

• Arthritis: Explicitly banned in the prompt ("Do not refer to arthritis in your answer").
• "Heart problems": Too vague. Use correct scientific terms like coronary heart disease or heart attack.
• Type 1 diabetes: Type 1 is an autoimmune disease, NOT linked to diet or obesity.