A group of students carried out a study of the population growth of flour weevils.

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:......

• K  -  555
• L  -    1020

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

​86th Day

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

​100   -  120

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

​Increase in population; because there is adequate food; the number of reproducing individuals is increasing; wastes products have not accumulated to toxic levels. 

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

• Diseases
• Lack of food
• Death rate equal to birth rate.

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