Standard 11 |Plant Kingdom | Mosses | Short Note For NEET BIOLOGY

 Chapter 3: Plant kingdom

Plant Kingdom | Mosses | Short Note For NEET BIOLOGY| standard 11

Note 8

Mosses 

> They're also called as Bryopsida

> As all Bryophytes, mosses they have two type of plant body in their life cycle - gametophyte and sporophyte

> Gametophyte is predominant stage - covers more time duration of life cycle

> Gametophyte has 2 stages

--> 1) Protonema stage: 

----> it develops directly from a spore

----> it is creeping

----> it is green (does photosynthesis)

----> filamentous

----> branched 

--> 2) Leafy stage:

----> it develops from secondary protonema (branch of protonema stage, which has developed from the first filament erupted from spore)

----> they develop as lateral bud

----> they have upright(erect) and slender axes

----> these axes have leaf life structures which are spirally arranged

> Gametophye stage has rhizoids - multicellular and branched - root like function

> Gametophye bears sex organs. 

> Reproduction :

--> Vegetative reproduction

----> by fragmentation

----> by budding (in secondary protonema)

Gametophye of Sphagnum 

--> Sexual reproduction

----> two types of sex organs are seen on Gametophye

----> 1) Antheridia - male sex organ - produce motile male gamete

----> 2) Archegonia - female sex organ - produce non-motile female gamete 

----> Sex organs are produced on the top (apex) of the leafy shoots

----> after fertilization - zygote develop into sporophyte (with foot, seta and capsule)

----> sporophyte of mosses is more detailed than liverworts 

> Spore dispersion in Mosses :

--> mosses have detailed mechanism for spore dispersal

--> spores are generated in capsule of sporophyte 

--> extra information (for better understanding): peristomial teeth are present at the end of capsule - they are hygroscopic (moisture absorbing) → as they come in contact with moisture they close themselves → spores inside capsule, stick to the teeth → when the moisture dries up → teeth open again → spores are dispersed from capsule

Funaria

> Common Examples of mosses: 

--> Funaria - green/common moss

--> Polytrichum - haircap moss - has ability to grow in very low moisture

--> Sphagnum - peat/bog moss

Happy Learning!

Thank you for reading!

Manish Mevada

Urvi Bhanushali