1

If your child is in P6, chances are he will see a lot of increase or decrease Population questions. Use these rules to tackle them.

2

Question :  If organism U decreases, explain how it will affect the population of organism P.

Student's Answer : There is lesser food for P and hence the P population decreases.

This answering is insufficient. When answering questions pertaining to the increase or decrease of a certain population, the student must show the understanding of the prey-predator relationship key concept.

Hence, it will be better to answer as below.

Model Answer : There will be lesser food for P as P feeds on U (prey-predator relationship key concept shown here) and thus the population of P decreases. 

3

Try this complex question as it involves more than one food chain.

Question : What willl happen to the eagle population if the population of mouse was to be removed from the food web ? Explain why.

Answer :  The population of the Eagle will decrease.

The snakes depend on the mouse for food. Without mice, the snakes will have lesser food and will decrease in population. The eagles depend on the snake and mouse for food. With no mice and fewer snakes, the eagles would have lesser food and decrease in population.