Pteriodophyta

Question 1

Classification and Examples

Answer 1

1) Psilopsida -
-Psilotum (Living fossil)
-Rhynia (fossil)

2) Lycopsida - (club moss)
-Lycopodium
-Silenginella
-Isoetes

3) Sphenopsida- (horse tail)
-Equisetum

4) Pteropsida- (fern)
-Pteridium
-Pterus
-Dryopterus
-Adiantum
-Azolla
-Salvinia
-Marcillia
-Ophyglossum

Question 2

Importance of pteridophytes

Answer 2

Used as soil binders, ornaments, medicinal purposes

Question 3

Habitat of pterido

Answer 3

• Cool, damp and shady places
  -Some may flourish well in Sandy soil conditions

Question 4

Plant Body

Answer 4

Sporophytic P.B.

Well differentiated roots, stem and leaf

• Root: Adventitious root
  (some pterido possess rhizoids)
• Stem: creeping/Ariel
  Underground stem : rhizome

-Leaf - 3 types
Sporophyll : bear sporangia
Trophophyll : Photosynthetic
Scaly small dry leaf : for protection

Question 5

Sporophyll form distinct compact structure called strobili/ cones in

Answer 5

Selanginella & Equisetum

Question 6

Macrophyllous and Microphyllpus leaves are found in:

Answer 6

1) Macrophyllous - Ferns, basically Pteropsida group

2) Microphyllous - Selanginella(ncert), Lycopodium, Equisetum

Question 7

What is heterosporous and homosporous pteridophyta? Which one is in majority?

Answer 7

Majority pteridophytes are homosporous:-

Homosporous: male and female gamete arise from same spore Ex.

Heterosporpus - different spores male and female gamete arise on
Ex. SIMAS (Selanginella[ncert], Isoetes, Marsilia, Azolla, Salvinia[ncert])

Question 8

Points about Heterosporous Pteridophytes

Answer 8

1. Megaspore and Microspore give rise to female and male gametophyte respectively.
2. Gametophyte depend upon sporophyte and the spores germinate on the sporophyte to give rise to male and female gametophyte (Endosporic germination)
3. Female gametophyte is retained on parent sporophyte for variable periods and the development of young embryo takes place within female gametophyte. This event is a precursor to seed habit

Question 9

Conditions for Seed habit

Answer 9

1. Endosporic germination
2. Heterosporous germination

Seed habit started in heterosporous pteridophytes but established in gymnosperm for the first time.

Question 10

Important Points

Answer 10

1) Haplo diplonatic life cycle
2) Show independent Alternation of Generations.
3) Reptiles of Plant Kingdom
4) Xylem lacks vessel and Phloem lacks companion cells
5) Sciophytes
6) First terrestrial plants

Question 11

Why is spread of living pteridophytes restricted to narrow geographical regions?

Answer 11

Specific, restricted habitat requirement and need of water for fertilization.