Select one of the following pairs of important features distinguishing Gnetum from Cycas and Pinus and showing affinities with angiosperms
the absence of resin duct and leaf venation
the presence of vessel elements and absence of archegonia
perianth and two integuments
perianth and two integuments
B.
the presence of vessel elements and absence of archegonia
Gnetum resembles angiosperms in many aspects.
i) The leaves in Gnetum have reticulate venation that is an angiosperm character.
ii) The presence of vessels in the xylem is also an angiosperm character and also found n Gnetum.
iii) In Gnetum female gametophyte is only partly cellular before fertilisation and becomes completely cellular only after fertilisation. Some of the free nuclei act as an egg as there is no archegonium.
The short apices in Gnetum and angiosperms show a distinct tunical and corps configuration.
The cortex of stem of Pinus is traversed by large resin ducts or canals. Each duct or canal is linked by a layer of thin -walled parenchymatous glandular secretory cells constituting epithelium. The epithelial cells secrete resin into the canal. The resin is the chief source of turpentine.
Flagellated male gametes are present in all the three of which one of the following sets?
Anthoceros, Funaria and Spirogyra
Zygnema, Saprolegnia and Hydrilla
Fucus, Marsilea and Calotropis
Fucus, Marsilea and Calotropis
In the prothallus of a vascular cryptogam, the antherozoids and eggs mature at different times. As a result
there is no change in success rate of fertilization
there is high degree of sterility
one can conclude that the plant is apomictic
one can conclude that the plant is apomictic
Moss peat is used as a packing material for sending flowers and live plants to distant places because
it is easily available
it is hygroscopic
it reduces transpiration
it reduces transpiration
The thalloid body of a slime mould (Myxomycetes) is known as
Autosomal
Cytoplasmic
Y-linked
Y-linked
In a moss the sporophyte
is partially parasitic on the gametophyte
produces gametes that give rise to the gametophyte
arises from a spore produced from the gametophyte
arises from a spore produced from the gametophyte
Which one of the following plants shows a very close relationship with a species of moth, where none of the two can complete its life cycle without the other?
Hydrilla
Yucca
Viola
Banana
In which of the following forms is iron absorbed by plants?
Ferric
Ferrous
Both ferric and ferrous
Free element