K.C.S.E Biology Q & A - MODEL 2008PP2QN06
An experiment was carried out to investigate transpiration and absorption of water in sunflower plants in their natural environment with adequate supply of water. The account of water was determined in two hour intervals. The results are as shown in the table below
(a) Using the same axes, plot graphs to show transpiration and absorption of water in grammes against time of the day
(b) At what time of the day was the amount of water the same for transpiration and absorption?
(c) Account for the shape of graph of:
(d) What would happen to transpiration and absorption of water if the experiment was continued till 05 00 hours?
(e) Name two factors that may affect transpiration and absorption at any given time
(f) Explain how the factors you named in (e) above affect transpiration
(b) 17.001- 19.99 hrs
(c) (i) Transpiration
1100 – 17000 (rapid) ( in the rate of transpiration) due to high light intensity/ high temperature
(ii) 17000 – 0300 hrs decrease (in the rate of transpiration) due to low light intensity/ absence of light/ in temperature.
11.00 – 1900 hrs. Increase (in the rate of atmosphere) of water to replace water lost- through transpiration
1900 – 0300 hrs; decrease ( in the rate of absorption of water) due to the fact that rate of transpiration has declined
(d) Both transpiration and absorption decrease accept decrease
(e) Wind; light, atmosphere pressure, humidity; temperature
Temperature - at high temperature the rate is higher/ at low temperature the rate is Low.
(f) Wind- rate of transpiration is high when it’s windy/ lower when air still
Humidity – when humidity is low, the rate of transpiration is faster/ when its
High the rate of transportation is low
Pressure- the rate is high at low atmosphere pressure at high atmosphere pressure the rate is low.