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Flashcards in Biology b Deck (76)
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Why is population rising ?

Modern medicine and farming methods mean less people are dying from disease and hunger


How does population affect the environment ?

Our increasing population puts pressure on the environment, as we take the resources we need to survive


How does a higher standard of living affect the environment ?

People demand luxuries such as cars and computers. This uses up raw materials and energy for the manufacturing processes. This means lots of resources are being removed from the environment quicker


Why are many resources going to run out ?

They are being used up quicker than they are being replaced


What pollution affect water ?

Sewage and toxic chemicals from industry can affect the plants and animals in the water


What pollutants affect land ?

Toxic chemicals such as pesticides.
Nuclear waste is buried underground
Household waste is left in landfill sites


What pollutants affect the air ?

Smoke and gases released into the atmosphere. Greenhouse gases like carbon dioxide are considered the most dangerous


What four main human activities reduce land and resources ?

1. Building
2. Farming
3. Dumping waste
4. Quarrying


What is deforestation ?

The cutting down of trees


Why is deforestation done ?

1. To provide timber
2. To clear land for farming


Why does so much land need to be cleared to grow crops ?

To provide food or grow biofuels such as ethanol


Why does deforestation mean more methane is released into the atmosphere ?

• Rice grows in warm, waterlogged conditions which is ideal for microorganisms, which release methane
• Cattle grown on the cleared land produce methane


Why is there more carbon dioxide in the atmosphere when trees are cut down ?

• Some trees are burnt when the land is cleared which releases carbon dioxide
• Microorganisms feeding on bits of dead wood release carbon dioxide through respiration
• less carbon dioxide is removed from the atmosphere through photosynthesis because there are less trees


Why is a reduction in biodiversity a bad thing ?

It is seen as a lost opportunity. The animals and plants that have become extinct could have had many useful products


What are bogs ?

Areas of land that are acidic and waterlogged


What is peat ?

The remains of partly rotted plants builds up to form peat


How do peat bogs restrict carbon dioxide entering the atmosphere ?

The plants only partly rot, so the carbon is stored in the plants


Why are peat bogs destroyed ?

1. The land is cleared for farming
2. The peat is dried and used as a fuel
3. Peat used as compost


What happens when a peat bog is destroyed ?

The peat starts decomposing so carbon dioxide is released. This adds to the greenhouse affect.


How can people reduce the influence of peat bogs on the environment ?

Buy peat free compost to reduce the demand for peat


Where is CO2 stored on earth ?

• Oceans, lakes and ponds
• Green plants as carbon compounds and photosynthesis removes it from the atmosphere
• peat bogs


What balances the temperature of earth ?

The heat it gets from the sun and the heat radiated back out into space


What do gases in the atmosphere do ?

Act as an insulating layer. Thy absorb most of the heat and re-radiate it in all directions


How do the gases in the atmosphere help us ?

At night they keep heat in the atmosphere, otherwise it would be very cold


What are greenhouse gases ?

Gases in the atmosphere that absorb and emit heat


Which greenhouse gases are scientists worrying about ?

Carbon dioxide and methane


What is global warming ?

The gradual increase in temperature of earth because of greenhouse gases


How do sea levels rise ?

As the sea gets warmer it expands. Some water comes from ice caps melting


What can climate change do to the weather ?

Changes the weather patterns which can make it extreme. Hurricanes form in areas where water is over 27 degrees, so more hurricanes could occur


What could happen to plants and animals from climate change ?

The distribution of the animals could change due to alterations in migration patterns