HUMAN IMPACT ON THE ENVIROMENT

Question 1

The increasing human populaltion requires an

Answer 1

increased food supply

Question 2

Methods of increasing food supply have included the use of;

Answer 2

fertilizers, pesticides, biological control and genetically modified (GM) crops.

Question 3

Fertilizers can leach from fields into freshwater increasing the effects of

Answer 3

algal blooms

Question 4

When algal blooms dies they are decomposed by aerobic bacteria which

Answer 4

multiply and reduce the oxygen concentration in the water

Question 5

Pesticides can accumulate in the bodies of

Answer 5

organisms and so build up along the food chain

Question 6

Toxicity levels of pesticides in the bodies of carnivores to the extent that the animal

Answer 6

or its reproduction is damaged

Question 7

The presence, abundance or absence of

Answer 7

indicator species can reveal information about the environment and level of pollution present.

Question 8

Biological control relies on natural solutions to

Answer 8

pest problems such as making use of natural predators or parasites

Question 9

Crop species can be genetically modified to increase their yields without the need for

Answer 9

fertilizers or pesticides

Question 10

Biological control and GM crops are alternatives to

Answer 10

intensive farming methods