Page 76 - General and Inorganic Chemistry for Advanced Secondary Schools Students Book Form Five and Six

Biology for Secondary Schools

Slime capsule fimbriae that attach themselves to

the lining of the urinary tract or the
Circular DNA
intestines. Example of the structure of
Cell wall bacterium with fimbriae is shown in

Cell membrane Figure 5.6.
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Cytoplasm
Fimbriae

Flagella

Figure 5.6: Bacterium with fimbriae
Figure 5.5: Generalised structure of a
bacterium Flagella
These are long tail-like structures that
Bacteria can be pathogenic or non-
pathogenic. help some pathogenic bacteria to move.
An example of bacteria with flagella is
Task 5.3 shown in Figure 5.5.
Search for information on pathogenic
and non-pathogenic bacteria from the Toxins
library and reliable internet sources. Some bacteria produce toxic
compounds that harm their hosts.
Pathogenic bacteria Human body reacts to the produced
These are bacteria that can cause toxins by inducing vomiting and
infections and diseases. Some of the diarrhoea in order to remove those
diseases caused by bacteria in plants toxins. For instance, toxins released
are fire blight and crown gall. In by Clostridium sp. can lead to severe
animals, bacteria cause diseases, such diarrhoea due to body reaction.
as tuberculosis, tetanus, cholera, and Bacteria also perform invasion and
gonorrhoea. Pathogenic bacteria have colonization; transformation; and
features that facilitate the spread of resistance. Invasion and colonization
diseases and infections which include happen when bacteria attack cells and
fimbriae or pili and flagella. tissues and reproduce rapidly. Bacteria
can transform themselves and become
Fimbriae or pili resistant to modes of treatment. For
Fimbriae are hair-like structures on example, the bacterium that causes
the surface of some bacteria. tuberculosis has become resistant to
For example, Escherichia coli have many antibiotics by transforming itself.

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