Page 63 - General and Inorganic Chemistry for Advanced Secondary Schools Students Book Form Five and Six

Biology for Secondary Schools

of whales, and wings of birds and discovered organisms into correct
bats are homologous structures. In groups they belong.
contrast, the wings of birds and wings (d) It allows addition of new features
of insects perform similar functions but when they are discovered.
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they are different origins hence, they
are analogous. Natural classification Disadvantages of natural system of
system uses homologous characters. classification

(a) It is very expensive since it involves
Advantages of natural system of experiments, researches, and high
classification level of classification skills.

(a) It allows organisms which are (b) It is tedious and time consuming
genetically and evolutionally related since it uses many features in
to be grouped together. grouping organisms.
(b) It is more accurate, since it involves (c) It is not stable because it can change

scientific research to gather enough any time due to discovery of new
information before the actual features or information. Table 4.1
placement of an organism into a shows the differences between
particular group is decided. artificial and natural systems of

(c) It enables placing of newly classification.

Table 4.1: Differences between artificial and natural system of classification

Artificial system of classification Natural system of classification
Considers external features only Considers both internal and external
features
Requires simple skills Requires advanced scientific skills

Based on an individual’s interest Based on international standards

It is usually fast and less expensive Takes more time and is expensive

Less accurate More accurate

Has limited predictive value Has high predictive value

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