the following diagram refers to an apparatus which is used to demonstrate a physiological process
I) what is the purpose of keeping potassium hydroxide solutions in test tubes X and Y?
ii) what is the purpose of keeping boiled peas soaked in a disinfectant in test tube Y?
III) why has the coloured water risen in tube A?
iv) Name the biological process which causes the water to rise in tube.
v) Name the products formed in X as a result of the process taking place
vi) why is there a slight rise of water in tubing B?
vii) What would you observe if the boiled peas in Y had not been treated with disinfectant?
Answers
Answer:
I) Potassium hydroxide is used as absorbent. It absorbs carbon dioxide released by germinating seeds.
ii) Boiled peas are soaked in order to reduce bacterial growth and hence, reduce error in evaluation due to bacterial growth.
III) Due to loss of carbon dioxide in the flask, a vacuum is created which causes the level of water to rise up.
iv) The experiment is carried to confirm carbon dioxide is released when aerobic respiration takes place.
v) During respiration, white precipitate of potassium carbonate and water is formed.
vi) It is because boiled seeds are dead seeds and can't respire. Hence, no oxygen is used up and no carbon dioxide is formed which causes minimal or no vacuum in tube B.
vii) If boiled peas in Y had not been treated, then bacterial growth would have occurred. Hence, it would have become difficult to deduce the cause of rise of water level and use of carbon dioxide by germinating seeds. The overall experiment would yield erroneous results.
Answer:
Potassium hydroxide solution is kept in test tube X and Y to check the presence of CO2, as KOH can absorb CO2, if it is produced
Explanation: