Circulatory systemIB MYP Biology: Mind map

Exam questions on Circulatory system

1. A cardiologist in Singapore is teaching trainee nurses how blood flows through the heart. Blood from the body returns to the right atrium and is pumped through the heart in a set order. She explains that one of her patients has a faulty valve that lets some blood leak backwards after each beat.
   Explain why a person with a leaking valve may feel tired.2 marks
2. A student in Auckland investigates how exercise affects her pulse rate. She counts her pulse for 30 seconds and doubles it to find the rate in beats per minute. She records it at rest and after 2, 4 and 6 minutes of running on the spot. Her results are 72, 104, 128 and 141 beats per minute.
   Describe the trend in her results and explain it.2 marks
3. A teenager in Delhi has iron-deficiency anaemia. Because she lacks iron, her body cannot make enough haemoglobin. She feels tired and becomes breathless when she climbs stairs.
   Explain why she feels tired and breathless.3 marks