Page 16 - Science Class 08

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The World of Microbes
• Microbes • Habitats of Microbes
• Chief Microbe Group: Bacteria, Fungi, Algae, Protozoa, Virus
MICROBES
Microbes are ny forms of life that surround
us– too small to be seen by the naked eyes.
They are found in water, in the soil and in the
air. The human body is also home to millions of
these microbes, also called microorganisms.
Some microbes make us sick, others are
important for our health. The most common
are bacteria, viruses and fungi. There are also
microbes from the group of protozoa. These
are ny living creatures that are responsible for
diseases such as toxoplasmosis and malaria.
Take a chapaa and leave it in the open for a
day or two. When you observe it through a
microscope, you will see whi sh small stalks
with black heads. These are microbes indeed.
Microbes can survive in almost every kind of
environment—hot water, icy water, salty water,
deserts, marshes and stormy areas. Not only
that, they are present in the human body and
also in decomposed organic ma er. Some
microbes live as parasites on the bodies of
other living beings. Generally, the body of a
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• Microbe-Culture
• Food Poisoning
microbe is covered with a hard covering. Such a
covering is called cyst.
Their Common Features
1. As men oned above, most microbes can
survive in all kinds of environment— hot,
cold, salty, sweet, sulphuric, etc.
2. Most microbes can reproduce on their
own. But some of them can grow a er
a aching themselves to other organisms
that are called their hosts.
3. Microbes are very tough and so they can
survive in extreme condi ons of heat, cold,
moisture, etc.
4. Some microbes are useful to us as well.
5. Most microbes cause diseases— bad cold,
fever, malaria, skin-troubles and influenza.
Their Chief Groups
Microbes occur in five major groups— bacteria,
fungi, algae, protozoa and viruses. Out of these
five groups, viruses are the niest as they have
no cellular structure. They thrive on the cells of
other living beings.
Science-8