AQA GCSE Science & Additional Science Biology 1 Topic 4 Hodder Education Revision Lessons Interdependence and adaptation Click to continue

AQA GCSE Science & Additional Science

Biology 1 Topic 4

Hodder Education Revision Lessons

Interdependence and adaptation

Interdependence and adaptation

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Biology 1 Topic 4

Overview

• Organisms are well adapted to survive in their normal environment.

• Population size depends on a variety of factors including competition, predation, disease and human influences.

• Changes in the environment may affect the distribution and behaviour of organisms.

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Biology 1 Topic 4

Competition

All animals and plants require a supply of materials from their surroundings and from other organisms that live there.For example, take a wild rabbit.

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Vibe Images/Fotolia

What does it need from its surroundings?What is it competing with?What limits the population of rabbits?


Biology 1 Topic 4

Plant competition

Plants also compete with other organisms to live.Take the example of a daisy on a lawn.

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Trancedrumer/Fotolia

What is it competing for?What is it competing with?What will limit the population of the daisies?


Biology 1 Topic 4

Competition summary

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Plants compete for Animals compete for

Light Food

Space Mates

Water Territory

Nutrients from the soil


Biology 1 Topic 4

Adaptation

Organisms, including microorganisms, have features and adaptations that enable them to get the materials they need from their habitat to survive.What adaptations are needed for typical organisms to live in these environments?

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• Very cold places like the Arctic and Antarctic• Hot, dry deserts• The depths of the oceans


Biology 1 Topic 4

Adaptations for cold environments

Some organisms need to cope with extreme cold, little light and snow. For example, polar bears have:

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• a thick layer of fat for energy and insulation

• thick fur for insulation• white fur for camouflage• large canine teeth for killing• large paws for swimming

Ilana Vargulich/Fotolia


Biology 1 Topic 4

Adaptations for hot, dry environments

Some organisms need to cope with extreme heat and lack of water. For example, camels have:

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• fat stored in a hump, as a supply of food and water

• thick fur for insulation for cold nights and hot days

• large feet for walking on soft sand• long eyelashes to keep sand out of

their eyes• nostrils that close during

sandstorms

Oleg Seleznev/Fotolia


Biology 1 Topic 4

Plant adaptations

Plants can also be adapted to live in dry environments. For example, cacti have:

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• large root systems• small surface area of leaves to

reduce water loss• waxy surfaces of leaves• water storage tissue

Lucy Cole


Biology 1 Topic 4

Environmental changes

Environments are changing constantly due to both living and non-living factors. This affects the distribution of the organisms living there.For example, populations of competitors or predators may change (these are living factors). Pollution, floods, droughts and temperature changes are examples of non-living factors.

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What would happen to the population of rabbits if the fox population was wiped out by hunting?How would an extended drought affect the wildlife in your area?


Biology 1 Topic 4

Monitoring environmental changes 1

Changes to the environment can be measured using non-living indicators, such as oxygen levels, temperature and rainfall.Living organisms also can be used as indicators of pollution:

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• Lichen populations can be used to determine levels of sulfur dioxide in the air.

• Invertebrates living in ponds and streams indicate water pollution and the concentration of dissolved oxygen.


Biology 1 Topic 4

Monitoring environmental changes 2

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Documents

AQA GCSE Science & Additional Science Biology 1 Topic 4 Hodder Education Revision Lessons Interdependence and adaptation Click to continue