Biology Le5

Question 1

Name 2 alternatives to using pestisides

Answer 1

Gm crops or Biological controll

Question 2

What are pesticides ?

Answer 2

Pestcides are chemicals used to kill unwanted organisms

Question 3

What substances are added to soil to improve nitrate levels?

Answer 3

Feratalisers

Question 4

What type of crop could be used to reduce fertaliser use?

Answer 4

Gm crop

Question 5

What is the first chain of event when fertaliser leaches into a loch

Answer 5

Fertalisers leach into fresh water adding extra un wanted nitrates

Question 6

What is the second chain of event when fertaliser leaches into a loch

Answer 6

This increases algal populations which can cause algal bloom

Question 7

What is the third chain of event when fertaliser leaches into a loch

Answer 7

Algal blooms reduce light levels and kill aquatic plants

Question 8

What is the fourth chain of event when fertaliser leaches into a loch

Answer 8

Dead plants aswell as algae become food for bacteria

Question 9

What is the final chain of event when fertaliser leaches into a loch

Answer 9

The bacteria uses up large quantitys of o2 avaliable for other organisms

Question 10

Give one advantage of using pesticides

Answer 10

increase in crop yeald

Question 11

Give one disadvantage of using pesticides

Answer 11

The decrease in bio diversty

Question 12

Explain what is ment by bio accumulation.

Answer 12

Bio accumulation is the build up of pesticides in an animals body fat

Question 13

Explain what is ment by bio magnification.

Answer 13

Bio magnification us when pesticides are passed along food chains and toxisity increases.