Select one of the following pairs of important features distinguishing Gnetum from Cycas and Pinus and showing affinities with angiosperms.
- Perianth and two integuments
- Embryo development and apical meristem
- Absence of resin duct and leaf venation
- Presence of vessel elements and absence of archegonia
Answer
(4) Presence of vessel elements and absence of archegonia
Solution
Gnetum is a gymnosperm, but unlike Cycas and Pinus it shows some angiosperm features.
Its xylem contains vessels (as in angiosperms), whereas other gymnosperms have only tracheids in the xylem.
Archegonia are also absent in Gnetum (as in angiosperms), whereas Cycas and Pinus have archegonia in the female gametophyte.
Hence the presence of vessel elements and absence of archegonia distinguish Gnetum and show its affinity with angiosperms.
Answer: (4)