1. Nitrates
WALT: state why nitrates are important and be able to analyse some data on minerals in plants

2. Last lesson, we learnt….. In order to survive, plants need …………
Plants are called producers because they ……………………………………. through ………………………
Today, we will look at one mineral in particular; nitrates.
Produce their own food through photosynthesis

3. Nitrates Nitrates are needed to make proteins
Just like in animals, proteins are needed by plants for………………..
Growth and repair
Nitrates are obtained from the soil and absorbed through the roots in the water
If the soil does not contain enough nitrates, farmers can use fertiliser (chemicals containing nitrates which are sprayed onto the soil)

4. The use of fertilisers can be a big problem if large amounts of nitrates run into rivers and streams. Can you think why?
Algae in the water overgrows and makes the water green.
This blocks the light for other plants in the water which die
Fish and larger pond animals die
Drinking water becomes polluted

5. This is a huge problem in Lake Naivasha

6. We are going to test the effect of different levels of nitrate on the growth of some cress seeds
How will we do this?
How will we keep it a fair test?

7. When you have set up your cress seeds
Put a sub-heading in your books “KS3 Science: Life Processes” “P.42, 43 and 44”
Answer the questions from the books in full sentences