Respiration practical

Question 1

Potassium hydroxide solution absorbs carbon dioxide.
Suggest a reason for absorbing carbon dioxide in this apparatus.
Woodlice
Potassium hydroxide solution
Coloured liquid 1 mark

Answer 1

1. reduces{volume/pressureofgas}/eq;
2. allows{measurementofoxygenused/movementof liquid / eq} ;

Question 2

Suggest what the syringe is used for in this apparatus. 2 marks

Answer 2

1.returningthecolouredliquidbacktozero/eq;
2. ideaofcalibration;
3. repetition/eq;

Question 3

*(b) Describe how this apparatus could be used to find the mean rate of respiration of woodlice. 6marks

Answer 3

referencetoconstanttemperature;
2. useofwaterbath/eq;
3. referenceto{suitable/stated/fixedtime/eq};
4. Referencetomeasuring{volume/distance};
5. descriptionofhowtoobtainvolume;
6. calculationofratedescribed/eq;
7. referencetoreplicates;
8. descriptionofcontrole.g.nowoodlice;
9. idea of welfare of animals important ;
10. reference to {mass / eq} of woodlice ;