Diversity in Living Organisms Notes

Aristotle’s classification

• Classification system was first designed by Sir Aristotle [384- 322 B.C.]. He classified all living organisms as plants and animals. Plants were further classified on the basis of their size and animals were classified on the basis of their habitat.

Limitations of Aristotle’s Classification

• Aristotle’s classification was based on habitat and same habitat can share different types of organisms.

Example:

Monera: Also known as Prokaryotae

• Prokaryotic: This phylum includes all organisms made up of prokaryotic cells, i.e., the cell in which well defined nucleus and membrane bound organelles are absent.
• Unicellular: These simple organisms are always unicellular, i.e., a single cell performs all life sustaining functions and able to live as an independent organism.
• Mode of nutrition: These organisms can be autotrophic or heterotrophic, i.e., either they can synthesize their own food or obtain their food from other organisms.

Example: