Question

The sequence of communities of primary succession in water is:
(A) Phytoplanktons → Scrubs → Free floating hydrophytes → Rooted hydrophytes → Grasses → Trees.
(B) Phytoplanktons → Free floating hydrophytes → Rooted hydrophytes → Trees → Scrubs.
(C) Free floating hydrophytes → Scrubs → Phytoplanktons → Rooted hydrophytes → Grasses → Trees.
(D) Phytoplanktons → Rooted hydrophytes → Free floating hydrophytes → Reed swamps → Marsh meadows → Scrubs → Trees.

• A. Phytoplanktons → Scrubs → Free floating hydrophytes → Rooted hydrophytes → Grasses → Trees.
• B. Phytoplanktons → Free floating hydrophytes → Rooted hydrophytes → Trees → Scrubs.
• C. Free floating hydrophytes → Scrubs → Phytoplanktons → Rooted hydrophytes → Grasses → Trees.
• D. Phytoplanktons → Rooted hydrophytes → Free floating hydrophytes → Reed swamps → Marsh meadows → Scrubs → Trees.

Hint:

Succession reflects the dynamic and adaptive nature of ecosystems.

Answer 1

The Correct Option is D

Phytoplanktons: These are the pioneer species, microscopic organisms that can photosynthesize and form the base of the food chain. 

Free-floating hydrophytes: These plants float on the water surface, such as Azolla and Pistia. 

Rooted hydrophytes: These plants are rooted in the sediment but have leaves that float or emerge above the water, such as Nymphaea (water lily).

Reed swamps: As sediment accumulates, emergent plants like reeds and sedges establish, creating a swampy environment. 

Marsh meadows: Further accumulation of sediment leads to the development of marshy areas with grasses and other herbaceous plants. Scrubs: With continued soil development and drainage, shrubs and bushes begin to colonize. 

Trees: Finally, trees can establish, leading to a climax forest community. 

Therefore, the correct answer is (D): Phytoplanktons → Rooted hydrophytes → Free floating hydrophytes → Reed swamps → Marsh meadows → Scrubs → Trees. 

Here is why option D is the best answer: Phytoplankton are the pioneers. Rooted hydrophytes prepare the way for free floating. Free floating are not the second to colonize. 

Reed swamps, marsh meadows, scrubs and trees is the correct order of terrestrial colonization. 

The best option is (D), keeping in mind the relative order of aquatic succession. 

The correct order is therefore (D) Phytoplanktons → Rooted hydrophytes → Free floating hydrophytes → Reed swamps → Marsh meadows → Scrubs → Trees.

Answer 2

Primary succession is the process of ecological development in an area that was previously uninhabited, such as newly formed land or water bodies.

In aquatic environments, phytoplanktons are the first organisms to colonize the area. They are followed by rooted hydrophytes (plants that grow in water), then reed swamps, marsh meadows, scrubs, and eventually trees.

Option (D) correctly represents the sequence of communities in primary succession in aquatic environments.