CONCEPT OF SPECIES It is already been stated that individual organisms which have many features in common and able to interbreed in natural conditions are encompassed by the term species. Species is the smallest basic unit of classification. Its proper characterization is, therefore, of vital importance for a 'Natural' scheme of classification. Identifying species on the basis of reproduction, John Ray (1693) considered all individuals produced by parents of the same types as members of the same species. Linnaeus and Some others distinguished species merely on the basis of structure. Morphological Concept of Species This is the most practical and widely used species concept to describe species since people began to classify organisms. Taxonomists use this concept mostly by default because they know most of the species on Earth only from their morphology. New species are usually named on the basis of morphological species concept; morphological descriptions are all that we need
Fission:
1- Occurrence of fission is only in unicellular organisms.
2- New organisms are formed as a result of parent cell dividing into two daughter cells. Thus, identity of parent is lost in fission.
3- Nuclear division is followed by cytoplasmic division.
4- Examples: Amoeba, Paramecium.
Budding:
1- Occurrence of budding is in both unicellular and multicellular organisms.
2- Parent gives new outgrowth to form new individual. Parent does not divide so its identity is retained in budding.
3- Cellular outgrowth is followed by the division of nucleus.
4- Examples: Planaria, Hydra.
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