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Asked by pritam | 19th Oct, 2009, 09:14: PM

Expert Answer:

Bryophytes are found in shady damp places on land. Hence they are also called amphibians of the plant kingdom. They are usually small in size. They probably were the earliest land plants. Like the rest of the land plants, they evolved from green algal ancestors, closely related to the Charophytes. 

The plant body shows differentiation into stem and leaf-like structures. But vascular tissues like xylem and phloem (for conducting water and food) are absent. They have no roots, only filamentous rhizoids, which are false roots. Rhizoids absorb water and minerals from the substratum. 

They have multicellular sex organs, i.e. the gametes are enclosed by a sterile jacket of cells. They retain the zygote within the female sex organ and allow it to develop into an embryo there.They are the only land plants with a dominant gametophyte.

Examples are common moss Funaria, Marchantia and Riccia.

 

 

In Pteridophytes, the plant body is differentiated into roots, stem and leaves. Also they show well developed vascular system i.e. xylem and phloem. These conduct water and other substances from one part of the plant to another. Pteridophytes have no flowers and do not produce seeds.

 

They are the first vascular plants that rapidly diversified to cover the earth. Unlike the Bryophytes, these plants are in the mainstream of land plant evolution and eventually gave rise to the seed plants. 

 

In all Pteridophytes the dominant plant is the sporophyte with the gametophyte short-lived.

Examples are Dryopteris, Marsilea, Azolla, Equisetum and Adiantum.

Answered by  | 22nd Oct, 2009, 08:36: AM

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