Question

The total number of species of plants, animals and microorganisms living on the Earth is called as
A. Biodiversity
B. Flora
C. Fauna
D. Ecosystem

Answer 1

Hint:-
Plants, animals and microorganisms are collectively known as organisms. Biologists have estimated that the earth is inhabited by a total of 8.7 million species out of which only 1.7 have been described.

Complete step-by-step solution:- The earth is home to a variety of organisms which are different from one another. They occupy different habitats and have different roles to perform in the ecosystem. This great variety of life on earth is known as Biological diversity or Biodiversity. Edward Osborne Wilson first coined the term biodiversity. Biodiversity gives us an idea of how different forms of life can coexist and survive in nature.
The diversity of life is a remarkable feature of earth. All levels of biological organization right from the macromolecules within the cells to biomes show diversity. Diversity within the species at the level of an individual gene is known as Genetic diversity whereas, diversity among various species found in an area is known as Species diversity. Biodiversity varies greatly from place to place. We can observe diversity at ecosystem level where one ecosystem varies from the other and contains different sets of organisms adapted for living in that particular ecosystem.
Biodiversity varies with a change in latitude or altitude, which means its distribution is not uniform on earth.
So, the correct answer is option (A), Biodiversity.

b>Note:- **
Of the total species of organisms discovered so far, close to 80% are animals and the rest 20% are plants that include algae, fungi, bryophytes, gymnosperms and angiosperms.
The International Day of Biological Diversity is celebrated on 22nd May. In the year 1992, the Convention on Biological Diversity was adopted on 22nd May in Nairobi Convention and later it was established at the Earth Summit held in Rio de Janeiro, Brazil from 5th June -14th June.