Aerobic respirationIB MYP Sciences: Mind map

Exam questions on Aerobic respiration

1. A long-distance runner in Nairobi trains every morning. Her muscle cells release energy from glucose using oxygen that she breathes in and her blood carries to them. The reaction goes on all the time, but it speeds up a great deal during a run.
   Write the word equation for aerobic respiration.2 marks
2. A hummingbird hovers in front of a flower and drinks sugary nectar. Its flight muscles beat about 50 times each second and are packed with a very large number of tiny structures in their cells. The bird breathes quickly and its heart beats very fast while it hovers.
   Explain why the hummingbird's breathing rate and heart rate both increase while it hovers.2 marks
3. A student in Dubai wants to show that living cells release energy. She fills two identical vacuum flasks, each with 100 g of dried peas that have been soaked in water. In flask A the peas are germinating. In flask B the peas have been boiled to kill them. Each flask is sealed with a cotton wool plug and a thermometer, and both start at 21.0 °C. After 24 hours the temperature in flask A is 26.5 °C and in flask B it is 21.3 °C.
   Identify the independent variable, the dependent variable and one control variable in this investigation.3 marks