The sequence of communities of primary succession in water is

1. Phytoplankton, sedges, free-floating hydrophytes, rooted hydrophytes, grasses, and trees.
2. Phytoplankton, free-floating hydrophytes, rooted hydrophytes, sedges, grasses, and trees.
3. Free-floating hydrophytes, sedges, phytoplankton, rooted hydrophytes, grasses, and trees.
4. Phytoplankton, rooted submerged hydrophytes, floating hydrophytes, reed swamp, sedges, meadow, and trees.
Ans. (d) The sequences of communities of primary succession in hydrosere are phytoplankton (pioneer stage) rooted submerged hydrophytes floating hydrophyte (floating stage)-> reed swamp- sedges- meadow and woodland (trees). The other options are wrong.

Page 251, XII NCERT