Transcript RevLessAQA_GCSESciB1_4PPt

AQA GCSE Science & Additional Science
Biology 1 Topic 4
Interdependence
Interdependence and
andadaptation
adaptation
Hodder Education Revision Lessons
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AQA GCSE Science & Additional Science
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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AQA GCSE Science & Additional Science
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.
What does it need from its
surroundings?
What is it competing with?
What limits the population of
rabbits?
Vibe Images/Fotolia
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AQA GCSE Science & Additional Science
Biology 1 Topic 4
Plant competition
Plants also compete with other
organisms to live.
Take the example of a daisy on a
lawn.
What is it competing for?
What is it competing with?
What will limit the population of the
daisies?
Trancedrumer/Fotolia
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AQA GCSE Science & Additional Science
Biology 1 Topic 4
Competition summary
Plants compete for
Animals compete for
Light
Food
Space
Mates
Water
Territory
Nutrients from the soil
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AQA GCSE Science & Additional Science
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?
• Very cold places like the Arctic and Antarctic
• Hot, dry deserts
• The depths of the oceans
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AQA GCSE Science & Additional Science
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:
• 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
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AQA GCSE Science & Additional Science
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:
• 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
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AQA GCSE Science & Additional Science
Biology 1 Topic 4
Plant adaptations
Plants can also be adapted to live
in dry environments. For example,
cacti have:
• large root systems
• small surface area of leaves to
reduce water loss
• waxy surfaces of leaves
• water storage tissue
Lucy Cole
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AQA GCSE Science & Additional Science
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.
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?
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AQA GCSE Science & Additional Science
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:
• 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.
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AQA GCSE Science & Additional Science
Biology 1 Topic 4
Christine Woodward
Monitoring environmental changes 2