Quest for greener greens

1	a) Explain how the use of nitrate-rich fertilisers has led to the destruction of 	freshwater ecosystems.
	b) What is the name given to this process?
	c) Name two areas in Britain where this has occurred.

2 	List all the factors which might limit the algae population in a fresh water 	system. Which one of your list is most likely to be the factor limiting the 		growth of the algae?

3 	Why does the addition of nitrate to the soil result in improved plant growth 	and crop yield?

4 	What is the role of nitrate reductase?

5 	How did scientists turn off the nitrate reductase gene in the roots of their 		experimental plants?

6 	How could switching on the gene for nitrate reductase throughout the life of 	a plant help us to deal with the problem of excess nitrate entering 			freshwater ecosystems?

7 	Make a list of the organic nutrients needed for plant growth and 			development. Explain what each is used for.