K.C.S.E Biology Q & A - MODEL 1997PP1QN20b

K.C.S.E Biology Q & A - MODEL 1997PP1QN20.

K.C.S.E Biology Q & A - MODEL 1997PP1QN19

K.C.S.E Biology Q & A - MODEL 1997PP1QN19

An experiment was carried out to determine the growth rates of bamboo and a variety of maize plants in two adjacent plots. The average height and average dry weight of plants from the two populations were determined over a period of twenty weeks. The data is as shown in the table below.

(a) Between which two weeks did the greatest increase in weight occur in
(b) Bamboo plants
(ii) Maize plants
(b) (i) Which of the two types of plants had a higher productivity by the end of the experiment
(ii) Give a reason for your answer in (b) (i) above
(c) Between weeks 14 and 18, the average height of the maize plants remained constant while average dry weight increased.
Explain this observation
(d) Suggest how the change in the average dry weight bamboo and maize
Plants would have been at week 22 if the experiment was continued.
(e) Why was it appropriate for this experiment to use
(i) Dry weight instead of fresh weight
(ii) Weight and height
(f) Describe how the average height and weight of the plants were determined in this experiment.
Average height
Average dry Weight
(g) Give a reason why secondary thickening does not occur in bamboo and  maize plants

​Figures 1 and 2 below represent reproductive organ of plants and an animal respectively.

​(a)  Which letters in figures 1 and 2 represents the organs that produce female gametes?
       Figure 1
       Figure 2
(b)  What is the function of the structure labeled S?
(c)  Name the structure labeled W
(d)  Which letters in figures 1 and 2 represents the structures where fertilization takes place
(e)  Which letter in figure 1 represents the structure where male gametes are produced?

In a breeding experiment, plants with red flowers were crossed. The produced 123 plants with red flowers and 41 with white flowers
(a) Identify the recessive character
Give a reason
(b) What was the genotype of the parent plants that gave rise to the plants with a red and white flowers?

K.C.S.E Biology Q & A - MODEL 1997PP1QN15

​(a) Name the process.
(b) What is the importance of the process to the mammal?
(c) What is the source of amino acids in this process
(d) What is the difference between essential and nonessential amino acids?

The diagram below represents a simplified nitrogen cycle.

​(a) Name the organisms that cause process E and J
(b) Name the process represented by F and H.
(c) Name the group of organism represented by G

 An experiment was carried out to determine the rate of transpiration in three plants A, B and C. Plants, A and B belonged to different species while plants B and C belonged to the same species. Plant C had all its leaves removed. The three plants were of similar size and were exposed to the same environment conditions. The results are as shown below in the graphs below

​(a) Suggest possible environment conditions under which the experiment was carried out between 30 and 60 minutes
(b) Account for the results obtained for plant C
(c) Suggest the habitat for plant A and B. Give reasons for your answer.
     Habitat for plant A
     Habitat for plant B

 A person was able to read a book clearly at arm’s length but at normal reading distance.
(a) State the detect the person suffered from?
(b) Why was he unable to read book clearly at normal distance
(c) How can the defect be corrected?

​The following below represents a feeding relationship in an ecosystem

​(a)  Write down the food chains in which the guinea fowls are secondary consumers
(b)  What would be the short term effects on the ecosystem if lions invaded the area?
(c)  Name the organism through which energy from the sun enters the food web.

 Name a disease caused by lack of each of the following in human diet.

• Vitamin D
• Iodine

K.C.S.E Biology Q & A - MODEL 1997PP1QN09.

A person was found to pass out large volumes of dilute urine frequently.
Name the
(a) Disease the person was suffering from
(b) Hormone that was deficient