K.C.S.E Biology Q & A - MODEL 2014PP1QN10

The diagram below shows a set up for an experiment to demonstrate a certain physiological process.

​(a) What nature of solution is represented by 20% sugar solution? 
(b) Explain the observation made on the set up after one hour.

K.C.S.E Biology Q & A - MODEL 2013PP1QN30

K.C.S.E Biology Q & A - MODEL 2013PP1QN05

K.C.S.E Biology Q & A - MODEL 2013PP1QN01

(a) In an investigation, equal amounts of water was placed in. three test-tubes labelled G, H and J. Pondweeds of equal length were dropped in each test tube. The test-tubes were then placed in identical conditions of light and carbon (IV) oxide at different temperatures for five minutes. After the five minutes, the bubbles produced in each test-tube were counted for one minute. The results were as shown in the table below.

​(i) Name one requirement for this process that is not mentioned in the investigation. 
(ii) Name the gas produced in this investigation. 
(iii) Account for the results in test-tubes H and J. 
(b) State two ways in which the human intestinal villus is adapted to its function. 

The diagram below represents an experimental set-up used by students to investigate a certain process.

​Flower Q produced seeds while P did not. Account for the results.

K.C.S.E Biology Q & A - MODEL 2012PP1QN13

The diagram below represents a set-up that students used in an investigation.

​(a) Name the physiological process that was being investigated. 
(b) State the role of potassium hydroxide in flask K. 
(c) Account for the observation in boiling tube L and flask N. 
L .
N 

In an investigation, a student extracted three pieces of paw paw cylinders using a cork borer.
The cylinders were cut back to 50 mm length and placed in a beaker containing a solution.
The results after 40 minutes were as shown in the table below.

​(a) Account for the results in the table above. 
(b) What would be a suitable control set-up for the investigation? 

K.C.S.E Biology Q & A - MODEL 2011PP2QN06

The diagrams below show an experimental set-up to investigate a certain process in a plant tissue.

Explain the results obtained after 30 minutes.

In an experiment to investigate a certain physiological process, a boiling tube labelled A and a test tube labelled B were covered with cotton wool. The two tubes were simultaneously filled with hot water and fitted with thermometers. The experimental set-up was as in the diagrams below.

​Temperature readings were taken at the start and after every two minutes for twenty minutes. The results were as shown in the table below.

(a) Using the same axes, draw graphs of temperature against time. 
(b) (i) Work out the rate of heat loss in the boiling tube labelled A and test-tube labelled B between the 5th and 15th minutes.
 A 
 B 
(ii) Account for the answers in (b) (i) above. 
(iii) How does the explanation in (b) (ii) above apply to an elephant and a rat? 
(c) (i) State the role of the cotton wool in this experiment. ,
(ii) Name two structures in mammals that play the role stated in (c) (i) above. 
(d) State three advantages of having constant body temperature in mammals. 

K.C.S.E Biology Q & A - MODEL 2010PP1QN07

An experiment was carried out to investigate the effect of temperature on the rate of reaction catalyzed by an enzyme. The results are shown in the table below

(a)On t he grid provided draw a graph of rate of reaction against temperature 
(b) When was the rate of reaction 2.6 mg of product per unit time? 
(c) Account for the shape of the graph between
(i) 5 C and 40 C 
(ii) 45 C and 60C 
(d) Other than temperature name two ways in which the rate of reaction between 5C and 40C could be increased 
(e) (i) Name one digestive enzymes in the human body which works best in acidic condition 
(ii) How is the acidic condition for the enzyme named in (e) (i) above attained? 
(f) The acidic conditions in (e) (ii) above is later neutralized
(i) Where does the neutralization take place?
(ii) Name the substance responsible for neutralization