question_answer 32)

  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?

Answer:

                   Cycas as the relic of past Cycas. is an evergreen plant which looks like a palm. It hasun branched stem and large compound leaf. It exhibit phylogenetic relationship with pteridophyte . Its evolutionary characters are (i) Slow growth. (ii) Shedding of seed when the embryo is still immature. (iii) Little secondary growth and manoxylic wood. (iv) Leaf like mega sporophyllus. (v) Flagellate sperms even when pollen tube is present. (vi) Persistent leaf bases. (vii)Circinate ptysix. (viii) Arrangement of microsporangia is well defined archegonia.