ALTERATION OF GENERATIONS IN ARCHEGONIATES.pptx

ALTERATION OF GENERATIONS IN ARCHEGONIATES.pptx

1. ALTERATION OF GENERATIONS IN ARCHEGONIATES Aroma Aishwarya Barla

2. ARCHEGONIATES? Archegoniates is a term used to describe a plant that has Archegonium . Archegonium is a female sex organ. It is found in Bryophytes, Pteridophytes and Gymnosperms

3. Point of INTEREST: ARCHEGONIUM Archegonium is a multicellular structure or organ of the gametophyte phase of plants, producing and containing an ovum or female gamete It is flask shaped with bulbous lower region and an elongated narrow neck region.

4. ALTERNATION OF GENERATION Observed in some lower plants A life cycle which involves two phases of life, which regularly alternates with the other. Thus, one life cycle has two generations. Gametophytic (n) Sporophytic (2n) This is called Alternation of generations. The Gametophytic generation gives rise to Sporophyte which in turn produces Gametophyte.

5. GAMETOPHYTE A haploid plant body that has single set of chromosome. Produce gametes by Mitosis ( equational division) Produces Zygote on fertilization.

6. SPOROPHYTE A plant body that has 2 set of chromosomes. Produces haploid spores by Meiosis. The spores then might undergoes mitosis to produce 4 daughter cells or spores. These spores produces gametophyte.

7. ALTERNATION OF GENERATION

8. Alternation of Generation in Bryophytes

9. Alternation of Generation in Pteridophytes

10. Alternation of Generation in HETEROSPOROUS Pteridophytes

11. Alteration of Generation in Gymnosperms