Write description of thallophyta, bryophyta and pteridophyta with examples of each.
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Thallophyta:
These are a group of non vascular plants under kingdom plantae.
Their body is not complexly differentiated.
They bear a thallus like body connected to a substratum through root like structures i.e. rhizoids.
They are usually found in moist or wet places.
This is because these plants lack “true roots” and vascular tissue (xylem and phloem) which are required for the transport of water and minerals.
They are autotrophic in nature.
Most of the members of this group are autotrophs i.e. they produce their own food.
Reserve food is stored in the form of starch.
Plants belonging to this group are Ulva, Chara, Spirogyra.
Bryophyta:
These are a group of non vascular plants under kingdom plantae.
Their body is slightly differentiated.
They bear roots, stems and leaves.
They are usually found in moist or wet places, and also known as the amphibians of the plant kingdom.
This is because they require water for the process of fertilization.
They are flowerless, seed less plants.
Most of the. members of this group are autotrophs i.e. they produce their own food.
Reserve food is stored in the form of starch.
Plants belonging to this group are liverwort, haircap moss, polytrichum.
Pteridophyta:
These are a group of vascular plants under kingdom plantae.
Members of this group are most primitive living vascular plants.
The main plant body is a sporophyte. It is differentiated into root, stem and leaves.
Plants (sporophyte) reproduce by spores formed in sporangia.
Sporangia grows either on the ventral surface or in the axil of leaves.
Plants may be homosporous or heterosporous.
It is independent and bears chlorophyll.
It bears male reproductive organs called antheridia and female reproductive organs called archegonia. Reproductive organs are multi cellular and jacketed.
Water is essential to effect fertilization as male reproductive units are flagellated and motile. Seed formation never takes place in living pteridophytes.
An embryo develops in situ after fertilization and the sporophyte remains attached to the gametophyte till the development of root.
Plants show clear alternation of generations. The two phases i.e. sporophyte and gametophyte are independent of each other.
Plants belonging to this group are marsilea, whisk fern, azolla.