Question

The correct sequence of plants in hydrosere is :

• A. Oak $\to$ Lantana $\to$ Volvox $\to$ Hydrilla $\to$ Pistia $\to$ Scirpus
• B. Oak $\to$ Lantana $\to$ Scirpus $\to$ Pistia $\to$ Hydrilla $\to$ Volvox
• C. Volvox $\to$ Hydrilla $\to$ Pistia $\to$ Scirpus $\to$ Lantana $\to$ Oak
• D. Pistia $\to$ Volvox $\to$ Scirpus $\to$ Hydrilla $\to$ Oak $\to$ Lantana

Answer 1

The correct option is C Volvox $\to$ Hydrilla $\to$ Pistia $\to$ Scirpus $\to$ Lantana $\to$ Oak

The various stages in a hydrosere are well studied in ponds, pools or lakes. The various stages of hydrosere are:
(i) Phytoplankton stage, e.g. some blue-green algae, green algae (Volvox), diatoms and bacteria, etc
(ii) Rooted sub-merge stage, e.g. Hydrilla, Vallisneria, etc
(iii) Floating stage, e.g. Nelumbo, Nymphea, etc. Some free-floating species are pistia, Azolla, Lemna.
(iv) Reed-swamp stage, e.g. species of Scirpus, Typha, etc.
(v) Sedge-meadow stage, e.g. species of Cyperaceae and Gramineae.
(vi) Woodland stage, e.g. Lantana, Salix, Populus, etc
(vii)Forest stage, e.g. Tropical rainforests, mixed forests of Alnus, Acer, Quercus (oak), tropical deciduous forests.
Therefore the correct sequence of plants in a hydrosere is
Volvox --> Hydrilla --> Pistia --> Scirpus --> Lantana --> Oak