Respiration 7.3-7.7 and CP16

Question 1

See A level Biology Folder

Answer 1

:)

Question 2

What indicates the rate of respiration?

Answer 2

Volume of oxygen take up/volume of carbon dioxide produced per unit time

Question 3

What does a Respirometer measure?

Answer 3

The volume of oxygen being take up in a given time - the more oxygen take up the faster the rate of respiration

Question 4

Each tube contains potassium hydroxide solution, what is this?

Answer 4

A solution that absorbs carbon dioxide

Question 5

How would a control tube be set up?

Answer 5

Exactly same way but instead of a mass of woodlice, use the mass of beads (non-respiring)

Question 6

Describe the experiment

Answer 6

• Set up the tubes with woodlice and beads
• Syringe set the fluid in the manometer to a know level
• Leave for 20 minutes
• Woodlice will cause a decrease in volume of air due to O2 consumption, reducing pressure and causing liquid to move towards the tube
• Measure the distance moved by the liquid in the time and then calculate volume of oxygen taken in per minute

Question 7

How would you get more precise results in the Respirometer experiment

Answer 7

Repeat the experiment and calculate a mean volume of oxygen