PLANT KINGDOM_PTERIDOPHYTE.PRIYA JHApptx

A pteridophyte is a vascular plant that reproduces by means of spores. Because pteridophytes produce neither flowers nor seeds, they are sometimes referred to as "cryptogams", meaning that their means of reproduction is hidden. Ferns, horsetails, and lycophytes are all pteridophytes

1. PLANT KINGDOM_ PTERIDOPHYTE PRIYA JHA PGT BIOLOGY

2. HAPLO DIPLONTIC LIFECYCLE

3. In pteridophytes gametophytes are inconspicuous even some time microscopic in size ,short life span Common groups i ) horsetail ii) Fern Uses- i )medicinal ii) soil binder iii)ornamental Habitat- i ) Found in cool,damp shady places ii) some may flourish well in sandt soil Plant Body- i )Mainly sporophyte ii)First plant to have xylem and Phloem so true root,stem,leaf present(no thallus structure)

4. In pteridophyte gametophytic stage is small inconspicuous but independent in nature. It perform photosynthesis itself. In its sporophyte no foot, seta and capsule so to form spores they produce Sporangium which is inside the special leaves called Sporophyll and it produce Spores Compact sporophyll is called Strobillus /Cone.

5. Zygote thereafter produces a multicellular well-differentiated sporophyte which is the dominant phase of the pteridophytes . The development of the zygotes into young embryos take place within the female gametophytes. This event is a precursor to the seed habit considered an important step in evolution.

6. Leaves of Pteridophyte I)Small eg Selaginella

7. II) Large leaves(pinnately Compound leaves) eg Fern

8. Types of Spores In majority of the pteridophytes all the spores are of similar kinds; such plants are called homosporous . Genera like Selaginella and Salvinia which produce two kinds of spores, macro (large) and micro (small) spores, are known as heterosporous. The megaspores and microspores germinate and give rise to female and male gametophytes, respectively.

9. SEED HABIT The origin of seed habit is associated with the following: ( i ) Production of two types of spores (heterospory). (ii) Reduction in the number of megaspores finally to one per megasporangium. (iii) Retention and germination of the megaspores and fertilization of the egg. (iv) Continued development of the fertilized egg into the embryo while still in situ.

10. The pteridophytes are further classified into four classes: Psilopsida (Psilotum); Lycopsida (Selaginella, Lycopodium) , Sphenopsida (Equisetum) Pteropsida (Dryopteris, Pteris, Adiantum) .