Question

A group of students carried out a study of the population growth of flour weevils. They put16grams and 64 grams of maize flour into two equal boxes K and L respectively. 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.
 

No. of days after introduction of weevils	Approximate No. of weevils present​
	K	L
0  5  40 60  80  100  120  135  150	20 20  200  550  560  650  640  650  645	20 20 300 800 1300 1750 1750 1740 1748

1. 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. 
2. What were the approximate numbers of weevils present in the two boxes on the 70th day.
   Number in K
   Number in L
3.    
   • On the what day was the population of weevils in K 580. 
   • Between which days was the population difference greatest. 
4. Account for the shape of graph L between day 5 and day 100. 
5. State factors that would make the human species assume the graph curve between day 100 and day 150.

Answer 1

1. 
   
2. Number in K - 555
   Number in L - 1020
3.   
   • 86th day
   • 100-120
4. Increase in population ; because there is adequate food ; the number of reproducing individuals is increasing ; wastes products have not accumulated to toxic levels;
5.    
   • Diseases
   • Lack of food
   • Death rate equal to birth rate