1. SATISH PRADHAN DNYANASADHANA COLLEGE, THANE (W)
S.Y.BSc SEMESTER III BOTANY PAPER I UNIT: II ALTERNATION OF GENERATION OF BRYOPHYTES
By Mr. Swapnil S. Kadam
DEPARTEMENT OF BOTANY
SATISH PRADHAN DNYANASADHANA COLLEGE, THANE (W)

2. Topic:- Alternation of Generation of Bryophyte

3. Alternation of Generations
1.Bryophytes are small nonvascular plants, i.e.
Bryophytes lack Vascular Tissues and have life cycles dominated by the gametophyte phase.
2. The Life cycle of Bryophytes are very Intresting.
3. It Splits into two Phases, each Represented by a separate adults.

4. Alternation of Generations
In a single life cycle there occur two distinct multicellular, vegetative Individuals.
The First one is Green Thalloid (liverworts) or leafy(mosses) plants. It is Independent plant which is most conspicuous. It is haploid and bears the sex organs(Anthredia & archegonia) which produce the Gamates(sperms and eggs). As it bears the Gamates, the Green Indivituals is called the Gametophyte. It is concerned with Sexual Reproduction.

5. Alternation of Generations
2. The other one Multicellular, Vegetative individual is Sporogonium. It is diploid and usually differentiated into Foot,Seta and Capsule.As the sporogonium is concerned with the production of the sporophyte Generation. It is less Conspicuous.

6. Alternation of Generations
The Gametophyte plant along with the structures produced by it constitutes the Gametophyte Generations.
In the life cycle it starts with formation of meiospores and consist of green individuals and the Sex organs.
The last structure formed during this phase are the Gametes. The Gametes fuse to form the zygote.

7. Alternation of Generations

8. Alternation of Generations

9. Alternation of Generations
From the above Explanation it is evident that on germination the Reproductive cells of one generation give rise to the alternate generations in the Life Cycle.
The two generations thus regularly alternate with each other in a single life cycle. This Biological phenomenon is called alternation of generatoions and Spogenic meiosis are termed diplohaplontic life cycles.

10. Alternation of Generations
In the Bryophytes alternation of Generations becomes as integral part of the Life Cycle.
It is a constant feature of all the species because the zygote invariably develops into a istinct sporophyte. This kind of alternation of Generations in which the alternating individuals are dissimilar is called Heterologus or Heteromorphic.

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