Unit 3 – Life On Earth Key Area Human Impact On The Environment

Human Impact On The Environment Man’s Impact on the environment – research task. Follow the instructions on the sheet in the resources folder. Your teacher will give you an impact to research and prepare a presentation on.

Learning Intention: Investigate the effects of an increasing human population. Success Criteria: Be able to state that increasing human population requires an increased food supply. Be able to identify problems with intensive farming. Intensive Farming

Starter On a whiteboard from your research task- State different impacts that man has on the environment.

The human population is continuing to increase. Some changes that have contributed towards this are- Improvements in medical care Industrial revolution Agricultural revolution Human Population

To provide enough food for the increasing population, methods of increasing food yields are needed. Farming is the main method of producing food. A lot of effort has gone into increasing yields from farms. Some of these methods of increasing food production have negative impacts on biodiversity as discussed in the last lesson. Human Population

This method involves growing single plant species, e.g wheat, in large fields. It allows- Efficient Planting Crop treatments Harvesting. Intensive Farming

Fertilisers are used by farmers to replenish minerals in the soil and improve growth of the crop, so increasing the yield. Pesticides are use to kill a range of pests that will affect the growth of a crop. Pesticides and Fertilisers

Fertilisers leach from fields into waterways such as rivers and ponds. This happens due to heavy rain washing fertilisers into waterways. This increases the growth of algae in the water which creates algal blooms. This is a large number of algae in the water which blocks out sunlight. Problems with use of fertilisers

Later in the year nutrients run out and there is less light for photosynthesis. Algae start to die and are broken down by aerobic bacteria. These bacteria increase and use up the oxygen reducing the oxygen concentration of the water. This results in the death of many organisms / 1252/ Problems with use of fertilisers

Pesticides are chemicals sprayed on crops to kill pests. Insecticides are sprayed on crops to kill insects which reduce crop yield. Some insecticides kill other insects as well as the target pests. This affects other organisms that feed on these pests and affect food chains. Problems with use of pesticides

Some pesticides are persistent and can build up in the bodies of organisms higher up the food chain. The levels of pesticide can build up to concentrations that can cause harm to organisms. This is called Bioaccumulation. vDjchttp:// vDjc Problems with use of pesticides

Learning Intention: Investigate the effects of an increasing human population. Success Criteria: Be able to state that increasing human population requires an increased food supply. Be able to identify problems with intensive farming. Intensive Farming

Learning Intention: Investigate the effects of different minerals on plant growth. Success Criteria: Be able to state the effect of different minerals on plant growth. Making Fertilisers

In this practical you are going to look at effects of different levels of minerals on plant growth. Read the background information sheet and then follow the instructions for the practical. Making Fertilisers

Learning Intention: Investigate the effects of Biological Control. Success Criteria: Be able to state that Biological Control relies on natural solutions to pest problems. Be able to identify Biological Control as an alternative to intensive farming. Biological Control.

Starter From last lesson, on a whiteboard write down- A description of intensive farming. Any two problems associated with use of fertilisers/pesticides.

Biological control involves using natural predators to control pest numbers. This works very well when the pest has been introduced to the ecosystem and has no natural predators. Biological Control.

The predator species has to be selected carefully to ensure that it will survive in the new environment and only attack the pest, not other species. It is also vital they do not carry disease or become a pest in the new are themselves. A trial should be carried out in a controlled area such as a greenhouse before releasing the species into the wild. Biological Control.

Select two examples from the videos on the next slides and for each one complete the table- Name of pest Name of species used as a control Basic info

Example – The cotton cushion scale insect. This insect was accidently introduced to California from Australia in the late 19 th Century. It multiplied and destroyed large numbers of crops. So a ladybird beetle, one of the scale insect’s natural predators was introduced from Australia. This reduced the numbers of the scale insect to a safe level allowing both species to coexist. Biological Control.

The Use of Barn Owls and Kestrels as Biological Control Agents (11mins) cnfHQ&feature=relatedhttp:// cnfHQ&feature=related Biological Control.

Biological Control of Greenhouse Pests zOl60http:// zOl60 Biological Control.

Cane Toads: An Unnatural History 1/5- what has gone wrong here??? OT-mmEhttp:// OT-mmE Biological Control.

"The Bugman" - March Biological Control - How To Use Beneficial Nematodes - Fly Control LPkY4 04LPkY4 Biological Control.

Learning Intention: Investigate the effects of Biological Control. Success Criteria: Be able to state that Biological Control relies on natural solutions to pest problems. Be able to identify Biological Control as an alternative to intensive farming. Biological Control.

Genetically Modified (GM) crops Learning Intention: Investigate the effects of GM crops. Success Criteria: Be able to state that a GM crop has had its genetic information altered. Be able to identify GM crops as an alternative to intensive farming.

Starter Discuss with a partner- What is biological control? Any examples of biological control.

wlB3Zkhttp:// wlB3Zk the-planet-1263/ the-planet-1263/ Genetically Modified (GM) crops

You are going to do a research task on GM crops covering the following points- What are GM crops? Examples of GM crops. How are GM crops altered? Why are GM crops beneficial? Genetically Modified (GM) crops

GM Challenge Your task is to produce an A5 information booklet about Genetically Modified crops. You must include…  Answers to the questions on the previous slide. You should include…  Examples of using GM crops.  Why GM crops are considered controversial. You could include…  A set of five questions at the back of your booklet about the information inside. To help you gather information with this task you may use any text book in the classroom (Int.2, higher) and the books in the library cupboard and box. and can have 30 minutes per pair on the computers for research.

Genetically Modified (GM) crops Learning Intention: Investigate the effects of GM crops. Success Criteria: Be able to state that a GM crop has had its genetic information altered. Be able to identify GM crops as an alternative to intensive farming.