A group of students carried out a study of the population growth of flour weevils. They put 16 grams of maize flour into two equal boxes K and L respective . They then introduced equal numbers of weevils into the boxes. The boxes were kept under similar environmental conditions. The weevils were counted at intervals and the results recorded in the table below.

(a) Using a suitable scale ,draw two graphs on the same axes from the results in the table.
Plot approximate number of weevils present on the Y – axis( Use graph paper provided) (8mks)

(b) What were the approximate number of weevils present in the two boxes on the 70th day.   (2mks)
Number in K: ..
Number in L:......

​(c) (i) On what day was the population of weevils in K 580. (1mk)

​(ii) Between which days was the population difference greatest . (1mk)

​(d) Account for the shape of graph L between day 5 and day 100. (4 mks)

(e) State factors that would make the human species  assume the graph curve above in K.    (4mks)

​The diagram below represents female reproductive system;

(a) Name the part labelled ;A ,B ,C and D. (4mks)

​A:

B:

C:

D:

​(b) State two functions of structure A. (2mks)

(c) How is part C adapted to its functions? (1mk)

​(d) Of what significance is part E to reproduction? (1mk)

​The diagram below represents a maize seedling.

​(a) Name the parts labeled P and Q. (2mks)

​P: 

​Q:

​(b) State the function of the part labeled R. (1mk)

​(c) Give three adaptations of the structure labeled S to its functions. (3mrks)

​(d) What is the role of air in germination of the above seedlings? (2mks)

​The diagram below shows a specialized cell from a human being.

​(a) Identify the cell. (1mk)

​(b) Name the parts labelled A,B, and C. (3mks)

A:

B:

C:

​(c) State the functions of the part labeled D. (1mk)

(d) A student observed cells under a microscope and counted six (6) cells a cross the diameter of view. The diameter of field of view was found to be 1.25mm. Calculate the length of one of the cells observed. ( Answer in micrometer). (3mks)

​a) Identify the type of asexual reproduction exhibited by yeast cells (1mk)

​b)  List down the functions of the following parts;     (3mks)

i)  Testis

​ii)  Fallopian tube

​iii) Urethra

State three ways how HIV and AIDS is transmitted in human population (3mks)

​a)  State the function of Juvenile hormone in insect metamorphosis    (1mk)

​b)  (i) Give a reason why most insects are serious crop pests at the larval stage     (1mk)

​(ii)  What happens at growth phase in insects growth curve     (1mk)

​(a) What type of response was being investigated above?  (1mk)

(b) Which of the set up above would act as a control experiment?  (1mk)

(c) Explain what happened in set up B after 24 hours  (2mks)

​(a) What  is meant by the following terms;     (2mks)

​(i) Ecosystem

(ii) Carrying capacity

​(b) Give two ways on how hydrophytes are adapted to the process of gaseous exchange     (2mks)