Human impact on the environment

Human impact on the environment

Human impact on the environment

In this lesson you will learn about:

• the biological control of pest species• the use of GM crops as an alternative to using

fertilisers and pesticides

Success criteriaExplain biological control of pest species worksExplain how GM crops can be used as an alternative to fertilisers and pesticides

Human impact on the environment

The biological control of pest species

• Can you name any common plant pest species?(aphids, scale insects)

• Can you name any common animal pest species?

(rabbits, rats)• Can you think of how these can be controlled

without using chemicals?

Human impact on the environment

Biological control of pest species is when the pest species numbers are controlled without the use of chemicals.Instead a biological control method is used.

Rabbits can become a problem for Landowners if numbers multiply too much.Why do you think this is?

A solution is to introduce the virus myxomatosis which infects and kills many of the rabbits

Human impact on the environment

The biological control of plant pest species includes: • Ladybirds to kill aphids and scale insects• Caterpillar moths to kill cacti

Why use these method instead of chemicals?

Human impact on the environment

The alternative is to use pesticides against the insects and plants.

These chemicals can be harmful to non-pest species directly and in run-off into fresh water.

Human impact on the environment

GM crops can be used as an alternative to using fertilisers and pesticides.

You have studied GM crops in a previous topic.

How can GM crops be used instead of these chemicals?

Human impact on the environment

Drought resistance can be transferred to the GM crop which will give better growth in dry conditions

Pest resistance will give enhanced yields for crops that might otherwise show a lesser yield

Human impact on the environment

Polish canola (Brassica rapa)Poplar (Populus sp.)Potato (Solanum tuberosum L.)Rice (Oryza sativa L.)Rose (Rosa hybrida)Soybean (Glycine max L.)Squash (Cucurbita pepo)Sugar Beet (Beta vulgaris)Sugarcane (Saccharum sp)Sweet pepper (Capsicum annuum)Tobacco (Nicotiana tabacum L.)Tomato (Lycopersicon esculentum)Wheat (Triticum aestivum

Alfalfa (Medicago sativa)Argentine Canola (Brassica napus)Bean (Phaseolus vulgaris)Carnation (Dianthus caryophyllus)Chicory (Cichorium intybus)Cotton (Gossypium hirsutum L.)Creeping Bentgrass (Agrostis stolonifera)Eggplant (Solanum melongena)Flax (Linum usitatissumum L.)Maize (Zea mays L.)Melon (Cucumis melo)Papaya (Carica papaya)Petunia (Petunia hybrida)Plum (Prunus domestica

Other GM crops include:

You could research one of them, and share with classif time allows

Human impact on the environment

There are differences of opinion about GM crops and there benefits.But remember to look at the science.

There are a lot of GM crops and the science is relatively new.