iGCSE Biology (0610)-9.2 Heart - iGCSE Style Questions Paper 3

Question

(a) Complete the description of the human circulatory system. The circulatory system is a system of blood vessels with a ………. and ………. to ensure one‑way flow of blood.

(b) A student investigated the resting heart rate in people of different ages. The student recorded the heart rate as the number of beats per minute (bpm).

(i) The student wore a watch that could monitor their heart rate. State two other methods that can be used to monitor heart rate.

(ii) Table 4.1 shows the results of the investigation.

Tick (✓) two correct conclusions that can be drawn from the data shown in Table 4.1.

(c) A 38‑year‑old person had a resting heart rate of 72bpm. The person exercised for 10 minutes. At the end of exercise their heart rate was 170bpm. Calculate the percentage change in heart rate from the beginning to the end of exercise for the 38‑year‑old. Give your answer to the nearest whole number. Space for working.

(d) A lack of physical activity is one factor that can increase the risk of coronary heart disease. Diet also has a role in the risk of coronary heart disease. Discuss the role of diet in reducing the risk of coronary heart disease.

▶️ Answer/Explanation

Solution

Ans:

(a) The circulatory system consists of blood vessels with a pump (heart) and valves to ensure one-way blood flow. The heart propels blood, while valves prevent backflow.

(b)(i) Two alternative methods to monitor heart rate:

Measuring pulse rate (e.g., at the wrist or neck).
Using an electrocardiogram (ECG) to detect electrical activity.

(b)(ii) Correct conclusions (✓):

Resting heart rate decreases until age 40, then increases.
From ages 5 to 10, heart rate decreases by 25 bpm.

(c) Percentage change calculation:

Change = 170 bpm – 72 bpm = 98 bpm.
Percentage change = \(\left(\frac{98}{72}\right) \times 100 \approx 136\%\).

(d) Diet’s role in reducing coronary heart disease risk:

Low saturated fats: Reduces LDL cholesterol, preventing artery plaque.
High fiber: Lowers blood cholesterol levels.
Limited salt/sugar: Controls blood pressure and obesity risks.
Antioxidant-rich foods: Protect blood vessels from damage.

Question

(a) Fig. 3.1 is a diagram of a cross-section of a human heart.

(i) Draw an X on Fig. 3.1 to identify the position of the left atrium.

(ii) On Fig. 3.1, label with a label line and the correct name a structure that ensures the one-way flow of blood.

(iii) State two letters that identify arteries in Fig. 3.1.

(iv) State the name of the part that separates the left and right sides of the heart.

(v) State the name of the main tissue the wall of the heart is made from.

(b) In one country, the percentages of males and females with coronary heart disease (CHD) in different age groups were recorded.

Fig. 3.2 shows these data.

(i) Using the information in Fig. 3.2, describe the similarities and differences between the percentages of males and females with CHD. [3]

(ii) State three risk factors for CHD not identified in Fig. 3.2.

▶️ Answer/Explanation

Solution

(a)(i) X should be drawn in the left atrium only, with a label line ending in left atrium.

Explanation: The left atrium is the upper chamber on the left side of the heart that receives oxygenated blood from the lungs. It’s important to place the X specifically in this chamber and not confuse it with the right atrium.

(a)(ii) Valve; valve identified with label line.

Explanation: The heart contains several valves (tricuspid, bicuspid/mitral, pulmonary, and aortic) that ensure one-way blood flow. Any one of these can be labeled. The valves prevent backflow of blood, maintaining the correct circulation direction.

(a)(iii) B and C (either order).

Explanation: Arteries carry blood away from the heart. In the diagram, B and C represent major arteries – likely the aorta and pulmonary artery. These have thick, muscular walls to withstand high blood pressure.

(a)(iv) Septum.

Explanation: The septum is the muscular wall that completely separates the left and right sides of the heart. This separation is crucial to prevent mixing of oxygenated and deoxygenated blood.

(a)(v) Muscle.

Explanation: The heart wall is primarily composed of cardiac muscle tissue (myocardium). This specialized muscle can contract rhythmically without tiring, enabling the heart to pump continuously throughout life.

(b)(i) Any three from:
– CHD increases with age for both males and females
– In age group 0-34 there’s no CHD in males or females
– More males than females overall have CHD
– Greatest difference between genders is in age group 75-84
– (Any valid comparative data quote between males and females)

Explanation: The data shows that while both genders see increased CHD with age, males are consistently more affected, particularly in older age groups. The complete absence in young people suggests CHD develops over time. The gender difference may relate to hormonal or lifestyle factors.

(b)(ii) Any three from:
– Unhealthy diet (high in saturated fats/cholesterol)
– Lack of exercise/physical inactivity
– Smoking
– High blood pressure
– Stress
– Genetic predisposition
– Obesity
– Diabetes

Explanation: While age and gender are shown in the data, many other modifiable risk factors contribute to CHD. Poor diet can lead to atherosclerosis, while smoking damages blood vessels. Lack of exercise weakens the cardiovascular system. These factors often interact, compounding risk.

iGCSE Biology (0610)-9.2 Heart – iGCSE Style Questions Paper 3

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