SCIENCE
PLANT KINGDOM
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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absence of resin duct and leaf venation
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presence of vessel elements and absence of archegonia
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perianth and two integuments
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embryo development and apical meristem
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Detailed explanation-1: -Final answer: The important features distinguishing Gnetum from Cycas and Pinus and showing affinities with angiosperms are the presence of vessel elements and the absence of archegonia.
Detailed explanation-2: -Gnetum species are characterized by such traits as decussate leaves, pinnate leaf veins, and the presence of vessels in stems, all of which resemble characters of angiosperms (Markgraf, 1930).
Detailed explanation-3: -Absence of resin ducts and leaf venation.
Detailed explanation-4: -Note: Cycas, Pinus, and Gnetum belong to the gymnosperms as they do not produce flowers. Gnetum shows an affinity towards angiosperms due to the presence of an element vessel and the absence of archegonia.
Detailed explanation-5: -Cycas resembles angiosperms in having ovules. Cycas are gymnosperms meaning their unfertilized seeds are open to the air to be directly fertilized by pollination, which have enclosed seeds with more complex fertilization arrangements.