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प्रश्न
Each plant or group of plants has some phylogenetic significance in relation to evolution: Cycas, one of the few living members of gymnosperms is called as the ‘relic of past’. Can you establish a phylogenetic relationship of Cycas with any other group of plants that justifies the above statement?
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उत्तर
Cycas is the connecting link between Gymnosperms and Pteridophyte. They show similarities with pteridophytes like flagellated antherozoids, circinate ptyxis, megasporophyll is leaf-like, presence of archegonia etc.
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संबंधित प्रश्न
Write a note on the economic importance of gymnosperms.
Describe the important characteristics of gymnosperms.
What do you infer from the term pycnoxylic?
Mention two characters shared by gymnosperms and angiosperms.
Read the following five statements (i to v) and select the option with all correct statements:
- Mosses and lichens are the first organisms to colonise a bare rock.
- Selaginella is a homosporous pteridophyte.
- Coralloid roots in Cycas have V AM.
- Main plant body in bryophytes is gametophytic, whereas in pteridophytes it is sporophytic.
- In gymnosperms, male and female gametophytes are present within sporangia located on sporophyte.
In gymnosperms, megaspore mother cell divides meiotically to form four megaspores. Out of four megaspores, one develops into a multicellular structure termed as : ·
Gymnosperms are called naked seeded plants due to the absence of
Which of the following is not found in gymnosperms?
Plants of this group are diploid and well adapted to extreme conditions. They grow bearing sporophylls in compact structures called cones. The group in reference is ______.
The giant Redwood tree (Sequoia sempervirens) is a/an ______.
In which plant will you look for mycorrhiza and corolloid roots? Also explain what these terms mean.
Which one of the following is the characteristic feature of gymnosperms?
