Chemicals And Living Things

Question 1

What happens when it rains

Answer 1

Some of the dissolved fertiliser is is washed away into rivers and streams this is called leaching

Question 2

What can excess fertiliser in a river do

Answer 2

It leads to a reduction in oxygen levels it increases growth of microscopic plant life it becomes overgrown

Question 3

What does the increased bacterial numbers do

Answer 3

Uses up all the oxygen it reduces oxygen for fish and invertebrates which die or move away

Question 4

What,why is done and problems if the land is cleared of hedges and trees

Answer 4

to create more land for crops this destroys habitats lack of roots which causes soil erosion

Question 5

What,why is done and problems this causes if , pesticides are used

Answer 5

To kill pests that’s compete with or harm the crops this can kill useful organisms as well as pests and ranges food webs

Question 6

Why and what’s the problems if fertilisers are used

Answer 6

They contain mineral salts that help plants to grow and increase the yield but can wash into streams and rivers and cause pollution that’s the organisms in the water die

Question 7

Why and what problems if biologic control is done

Answer 7

To control pests without using chemicals, the agents may become pests themselves

Question 8

What do fertilisers contain and do

Answer 8

Nutrients needed by plants they help plants to grown and are used by farmers horticulturists and gardeners