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Principles of classification
4. Classify the specimens into five was called Family, which was created
groups. Give reason for your by Michael Adanson in 1763, and it was
classification. allocated between order and genus. The
second group termed Division or Phylum
5. Briefly comment on the
evolutionary relationship among (plural phyla) was introduced by Ernst
the organisms placed in the same Haeckel in 1866 and it was assigned
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group as in question 4. between kingdom and class, making seven
hierarchical groups, namely Kingdom,
Phylum, Class, Order, Family, Genus,
and Species (Figure 2.1), which are still
Safety precautions being used by taxonomists today. Phylum
Necessary precautions should be is used in animal classification while
observed when collecting specimens Division is used in plant classification.
from the school surroundings and The systematic way in which organisms
nearby environment since there might are classified in ranks or taxonomic
be dangerous organisms like snakes, groups from kingdom to species level is
bees, thorn plants, and allergens. called taxonomic hierarchy or taxonomic
ranking. Any named group or rank within
2.3 Taxonomic ranks the hierarchy such as kingdom or phylum
is referred to as a taxon (plural taxa). A
Task 2.3
Search from internet source videos taxonomic rank is therefore a level at
or images showing taxonomic ranks. which an organism is placed within the
Note what you have observed. hierarchy.
Kingdom: Animalia
The classification system by Carolus
Linnaeus of 1700s introduced a systematic Phylum: Chordata
way of grouping organisms stepwise,
from a very broad group of organisms Class: Mammalia
called Kingdom to narrow group of Order: Primates
organisms called species. Linnaeus,
recognising the natural variations Family: Hominidae
existing among organisms divided them Genus: Homo
into five broad groups. He arranged the
groups hierarchically from the broadest Species: Homo sapiens
to the smallest in terms of the number
of organisms in each. Originally, these Figure 2.1: Taxonomic hierarchy of
groups were Kingdom, Class, Order, human being
Genus (plural Genera), and Species. The number of common characters across
However, later on, two more groups were taxa increases down the hierarchy from
introduced. The first introduced group kingdom to species level. Organisms placed
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