Question

Match the two sets.

	Column I		Column II
I	Pioneers replacement	A	Vegetation which modifies its own environment and thus, causing its own
II	Autogenic succession	B	Replacement of existing community by external conditions
III	Allogenic succession	C	Establishment
IV	Ecesis	D	Primary colonisers

• A. I- D, II- A, III- B, IV- C
• B. I- A, II- B, III- C, IV- D
• C. I- B, II- A, Ill- D, IV- C
• D. I- A, II- D, Ill- C, IV- B

Answer 1

The correct option is A I- D, II- A, III- B, IV- C

Pioneer species are those species which gets colonize in the area which did not contain any inhabitant previously. Algae are the best example of pioneer succession as because it invades the barren rocks. In general, pioneer species are autotrophs or those that maintain harmonious ecological interaction with autotrophic bacteria, herbaceous plants, lichens.

Autogenic succession is succession driven by the biotic components of an ecosystem.

In contrast, allogenic succession is driven by the abiotic components of the ecosystem.

Establishment (ecology) or ecesi is the process by which a plant or animal becomes established in a new habitat.

Thus, the correct answer is option A.