TNPSC Free Notes Biology – Pteridophytes

இந்தக் கட்டுரையில், TNPSC குரூப் 1, குரூப் 2, குரூப் 2A, குரூப் 4 மாநிலப் போட்டித் தேர்வுகளான TNUSRB, TRB, TET, TNEB போன்றவற்றுக்கான  முறைகள் இலவசக் குறிப்புகளைப் பெறுவீர்கள்.தேர்வுக்கு தயாராவோர் இங்குள்ள பாடக்குறிப்புகளை படித்து பயன்பெற வாழ்த்துகிறோம்.

Pteridophytes

General Characters of Pteridophyte:

 Pteridophytes are the first true land plants with xylem and phloem.
 Hence it is called vascular plants.
 Pteridophytes also exhibit alternation of generation.
 The diploid saprophytic phase alternates with the haploid gametophytic
phase.
 The main plant body is sporophytes, which is the dominant phase,
differentiated into true root, stem and leaves.
 Sporophytes reproduce by means of spores. Spores are produced in
sporangium.
 The sporangia bearing leaves are called sporophyll.
 Most of the plants produce only one type of spore it may be either
microspore or megaspore (homosporous).
 In some plants two types of spores are produced. They are microspore and
megaspore (heterosporous).
 Spores give rise to gametophytic generation called prothallus, which is
short lived and independent.
 The gametophytes produce the multicellular sex organs, Antheridium
which produces antherozoid (male gamete) and archegonium which
contains an egg. (female gamete)
 The antherozoid fertilizes with egg and form diploid zygote.
 It develops into an embryo which grows and differentiate into sporophyte.

Classification of Pteridophytes:
Reimer (1954) proposed a classification for Pteridophytes. In this
classification, the Pteridophytes are divided into five subdivisions.
1. Psilophytopsida
2. Psilotopsida
3. Lycopsida
4. Sphenopsida
5. Pteropsida.
There are 19 orders and 48 families in the classification.

Economic Importance
Pteridophyte Uses
Rumohra adiantiformis (leather leaf fern) Cut flower arrangements
Marsilea Food
Azolla Biofertilizer
Dryopteris filix–mas Treatment for tapeworm.
Pteris vittate Removal of heavy metals from soils – Bioremediation
Pteridium sp. Leaves yield green dye
Equisetum sp. Stems for scouring
Psilotum, Lycopodium, Selaginella, Angiopteris, Marattia Ornamental plants

**************************************************************************