Practical: Respiring Seeds

Question 1

How is the release of heat from respiring seeds measured?

Answer 1

Place seeds with moist cotton wool in a thermoflask. Measure temperature at the start of the practical and after a few days.

Question 2

How is the control set up for investigating the release of heat?

Answer 2

Set up another thermoflask with boiled seeds and measure any temperature change.

Question 3

Why are boiled seeds used for the control?

Answer 3

Boiled seeds cannot respire, so it shows that any further change in the temperature using the live seeds are due to respiration.

Question 4

Which reagent can be used to indicate carbon dioxide level?

Answer 4

Hydrogen carbonate indicator.

Question 5

What is the change in the carbon dioxide content of air released from the respired seeds and why?

Answer 5

Carbon dioxide is released during the respiration of the seeds.

Question 6

What is the function of sodium hydroxide in the practical set-up?

Answer 6

To act as a carbon dioxide absorbant.