Title: Life Cycles in Plants and it Types (With Diagram)
Headings: Life Cycles in Plants and it Types (With Diagram)
Life Cycles in Plants and it Types (With Diagram)
Types of Plant Life Cycles (Fig. 4.1):
On this basis, life cycle may be three types:
(i) Uniphasic:
(ii) Diphasic:
(iii) Triphasic:
(a) Haplontic life cycle:
(b) Diplontic life cycle:
(c) Haplo-diplontic life cycle
(d) Haplobiontic (= haplo-haplontic) life cycle:
(e) Diplobiontic (= diplo-diplo-haplontic):

Content: ADVERTISEMENTS: In the life cycle, change of ploidy level from diploid (2n) to haploid (n) is brought about by meiosis and fertilization (syngamy) respectively. The sporophyte generation is “diploid” in which meiosis occurs to produce haploid spores, while gametophyte generation is “haploid” in which gametes are produced (by mitosis of haploid cells). In the life cycle, any one of the two generations is found to be always more conspicuous and survive a greater proportion is called as dominant generation. In algae and bryophytes the somatic or vegetative plant body is a gametophyte which is dominant and visible. But in pteridophytes, gymnosperms and angiosperms the visible plant body is a sporophyte which is dominant and the gametophyte generation is less conspicuous (Fig. 4.2). In the life cycle diagram, the dominant generation should be placed in the top half of the cycle. Plant life cycles differ from animal life cycles by adding a haploid gametophyte generation after meiosis and before the production of gametes. ADVERTISEMENTS: