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Chapter 5 Understanding Diversity Of Organisms - Coggle Diagram
Chapter 5
Understanding Diversity Of Organisms
The variety of life
The existence of many kinds of organisms on earth is called
biodiversity
.
There is a wide variety of organisms on earth.
However, variety does not only exist within organisms as a whole. Variety also exists within smaller groups of organisms.
Different kinds of dogs belong to the same canine family but look different.
What are the threats to biodiversity?
Disease - Plants infected by a fungus could be wiped out if the disease is allowed to spread.
Excessive hunting - Tiger are now endangered because they were over-hunted for their skin and meat.
Invasion of other organisms - In Singapore, the American bullfrog ( non-native ) eats the smaller local frogs. This threatens the survival of the local frogs.
Change or loss of habitats - Land is cleared for industry, farming and housing. As a result, the giant panda has lost much of its home and source of food.
Why is
biodiversity
important in natural systems?
Coral reefs are rich in
biodiversity
. They support about 25% of all fish in the world.
In 1998, a rise in 1-2 degrees celsius in sea temperature resulted in the death of many corals around the world, including those found in Singapore.
Points
If all corals were gone, the diversity and balance of life in the sea would be lost.
Natures systems are complex networks of different organisms that depend on one another.
When a kind of organism in the system no longer exists, the system becomes
unstable
.
The same applies to other systems including rainforests and oceans.
Biodiversity is important to maintain the stability of systems in nature
.
Main idea
What are the benefits of biodiversity to humans?
Points
Biodiversity is important to maintain a stable system in nature. All the species in a system are interdependent.
Honeybees help to fertilise crops which are important sources of food for humans and other organisms. Without honeybees, life on earth would be hard to sustain as there would be no honeybees to fertilise crops on a large scale.
The organisms found in nature provide valuable resources. These resources include:
Raw materials e.g wood to build furniture and houses.
Food e.g spices
Medicines e.g antibiotics
What can we do to preserve biodiversity on earth?
Conserving wildlife and their natural habitats helps to maintain biodiversity.
side note
Volunteering with wildlife conservation organisations such as the World Wide Fund for Nature ( WWF ) and the Nature Society ( SG ).
Helping to spread the word of the importance of protecting wildlife. For example, WWF is creating awareness for the conservation of coral reefs which are severely threatened by drastic weather changes.
Stopping the introduction of non-native species into the environment. For example, we should refrain from releasing unwanted pets into the wild. This is because the pet might die or breed and/or upset the biodiversity in the area.
Limiting the usage of natural resources by recycling and reusing material. This is because the usage of natural resources destroys habitats and disturbs the biodiversity in an area.
How do scientists classify organisms?
A
dichotomous key
is usually used by scientists
( biologists ) to classify organisms.
A dichotomous key shows how objects or organisms are classified, according to their
similarities
and
differences
.
We can use a dichotomous key to:
-Classify organisms
-Identify organisms
Example of a dichotomous key.
Bacteria
Are organisms that cannot be seen by the naked eye.
Can be found in all types of places such as water, soil, food and even in our body!
Different kinds may be harmful or beneficial to us. Harmful bacteria can cause acene, diseases and bad breath.
How can bacteria be beneficial to us?
Waste treatment
Certain kinds of bacteria are used in waste treatment plants to break down waste into harmless products.
Food production
Certain kinds of bacteria are used to convert milk into food products such as yoghurt.
Digestion
The same kind of bacteria used in yoghurt production is used in our body to digest food. These bacteria are found in our intestine.
