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प्रश्न
A Prothallus is ______.
विकल्प
A structure in pteridophytes formed before the thallus develops
A sporophytic free living structure formed in pteridophytes
A gametophyte free living structure formed in pteridophytes
A primitive structure formed after fertilization in pteridophytes
उत्तर
A Prothallus is a gametophyte free living structure formed in pteridophytes.
Explanation:
In pteridophytes, meiosis or R/D occurs at the time of spore formation. The spores germinate to give rise to inconspicuous, small but multicellular, free-living, mostly photosynthetic thalloid gametophytes called prothallus. Prothallus represents the gametophytic phase in pteridophytes.
APPEARS IN
संबंधित प्रश्न
Briefly comment on the significance of heterospory.
Differentiate between the following:
Homosporous and heterosporous pteridophytes
Which one of the following belongs to vascular cryptogams?
In the prothallus of vascular cryptogram, the antherozoids and eggs mature at different times. As a result,
Genera like Selaginella and Salvinia produce two kinds of spores. Such plants are known as ______
The main plant body in Pteridophyte is ______.
Heterospory i.e., formation of two types of spores – microspores and megaspores is a characteristic feature in the life cycle of a few members of pteridophytes and all spermatophytes. Do you think heterospory has some evolutionary significance in plant kingdom?
The heterosporous pteridophytes show certain characteristics, which are precursor to the seed habit in gymnosperms. Explain.
How are the male and female gametophytes of pteridophytes and gymnosperms different from each other?
Gametophyte is a dominant phase in the life cycle of a bryophyte. Explain.
