Classification system changes when more information becomes available about the organisms. Additional information are updated from time to time about different organisms at this stage there is a need arises to make changes in the classification system.

Question - 3 : -
What different criteria would you choose to classify people that you meet often?

Answer - 3 : -

In our day to day life we categorize people based on following criteria:

1. Level of education

2. Profession

3. Height and skin colour

4. Native place

5. Sex

6. Hobbies

7. Nature

Question - 4 : -
What do we learn from identification of individuals and populations?

Answer - 4 : -

Identification of individuals and populations determine their exact place or position in the set plan of classification.

Question - 5 : -
Given below is the scientific name of mango. Identify the correctly written name.
(a) Mangifera Indica
(b) Mangifera indica

Answer - 5 : -

(b) Mangifera indica

Question - 6 : -
Define a taxon. Give some examples of taxa at different hierarchial levels.

Answer - 6 : -

Taxon is a group of real organisms contained in any category. A natural taxon refers to a group of similar, genetically related individuals having certain characters distinct from those of other group.

For example, all the insects form a taxon. So do birds, reptile, algae, grasses, dog, lion and man. Some examples of taxa at different hierarchial levels are:

(a) The taxon of bacteria is monera and their category is kingdom.

(b) The sponges form the taxon porifera and their category is phylum.

Question - 7 : -
Can you identify the correct sequence of taxonomical category?
(a) Species ———> Order ———> Phylum ———> Kingdom
(b) Genus ———> Species ———> Order ———> Kingdom
(c) Species ———> Genus ———> Order ———> Phylum

Answer - 7 : -

Question - 8 : -
Try to collect all the currently accepted meanings for the word ‘species’. Discuss with your teacher the meaning of species in case of higher plants and animals on one hand and bacteria on the other hand.

Answer - 8 : -

Species is one of the basic units of biological classification. A species is often defined as a group of organisms capable of interbreeding aid producing fertile offspring.
Sometimes more precise or differing measures such as similarity of DNA, morphology o,^ecological niche are used to define the basis of species.
In case of animals, the name of species is defined by the specific name or the specific epithet. For example, gray wolves belong to the species Canis lupus, golden Jackals to Cams aureus etc.
Both of them belong to same genus Canis, but species name varies. But species name of plant is only called species epithet.
The ‘specific name’ in botany is always the combination of genus name and species epithet such as saccharum in Acer saccharum (Sugar maple).
But bacteria are grouped under four categories based on their shape – spherical, rod-shaped, comma and spiral shaped and species of bacteria is according to their shapes. Thus the meaning of species in higher organism and bacteria are different.

Question - 9 : -
Define and understand the following terms:
(i) Phylum (ii) Class (iii) Family (iv) Order (v) Genus

Answer - 9 : -

(i) Phylum : A phylum is group of related classes having some common features, e.g., protozoa.

(ii) Class : A class is group of related orders, for e.g., order Rodentia, Lagomorpha and Carnivora all having hair and milk glands are placed in class mammalia.

(iii) Family : A family is a group of related genera. The genus Felis of cats and the genus Panthera of lion, tiger and leopard are placed in the family Felidal.

(iv) Order : An order is a group of related families. The family Felidae of cats and the »family Coridal of dogs are assigned to the order carnivora. Cats and dogs have large canine teeth and are flesh-eaters.

(v) Genus : A genus is a group of species alike in the broad features of their organization but different in detail. As per the rules of binomial nomenclatures, a species can not be named without assigning it to a genus.

Question - 10 : -
How is key helpful in the identification and classification of organism?

Answer - 10 : -

Key refers to a set of alternate characters in such a manner that helped for identification of plants and animals by selecting and eliminating the characters according to their presence or absence in the organism.

Every taxonomic category like family, genus and species has separate taxonomic key. There is species key for the identification of species in a genus and genus key is for the identification of genus in a family and so on.

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