Question

In autogenic succession
(A) the community itself alters its environment thus causing its replacement by a new community
(B) Early dominance of heterotrophs
(C) Replacement of existing communities due to external conditions
(D) Early and continuous dominance of autotrophic organism

Answer 1

Autogenic succession implies ecological succession navigated by biotic factors into an ecosystem and although the mechanisms of autogenic succession have been discussed for a long time the process of living things informing the advancement of succession was understood early on.

Complete answer
Option (A) The community itself modifies its environment thus causing its replacement by a new community.
Auto-" signifying individual or similar, and "-genic" signifying formulating or effecting. Hence, Autogenic succession links to ecological succession navigated by biotic factors within an ecosystem, which accordingly gives rise to modifications in the environment. For representation, the plants themselves induce succession to occur, leading to an incremental ecological change in a specific spot of land, noticed as a progression of inhabiting species.
Option (B) Early dominance of heterotrophs.
This option is not correct. Heterotrophic succession is distinguished by the early dominance of heterotrophs and starts in a predominantly organic environment.
Option (C) Replacement of existing communities due to external conditions.
This option is not correct.
Option (D) Early and continuous dominance of autotrophic organisms.
This option is not correct.

So, the correct answer is (A) the community itself modifies its environment thus causing its replacement by a new community.

NOTE: Ecological successional is an incremental modification that can be induced by either endogenous or exogenous components. If the changes induced by endogenous factors (the plants themselves) are named autogenic, whereas alterations caused by exogenous factors are named allogeneic.