Gymnosperms are also called soft wood spermatophytes because they lack
cambium
phloem fibres
thick-walled tracheids
thick-walled tracheids
D.
thick-walled tracheids
Gymnosperms lack xylem fibres. Large amount of parenchymatous cells are present with secondary xylem tracheids. So, these are also known as softwood spermatophytes.
Read the following five statements and answer as asked to them
I. In Equisetum the female gametophyte is retained on the parent sporophyte.
II. In Ginkgo male gametophyte is not independent.
III. The sporophyte in Riccia is more developed than that in Polytrichum.
IV. Sexual reproduction in Volvox is isogamous.
V. The spores of the above statements are correct?
Two
Three
Four
Four
The second stage of hydrosere is occupied by plants like
Azolla
Typha
Salix
Salix
Read the following five statements (I to V) and select the option with all correct statements.
I Mosses and lichens are the first organisms to colonise a bare rock.
II .Selaginella is a homosporous pteridophyte.
III. Coralloid roots in Cycas have VAM.
IV. Main plant body in bryophytes is gametophytic, whereas in pteridophytes it is sporophytic.
V. In gymnosperms, male and female gametophytes are present within sporangia located on sporophyte.
I, III and IV
II, III and IV
I, IV and V
I, IV and V
A prokaryoticv autotrophic nitrogen-fixing symbiont is found in
Cycas
Cicer
Pisum
Pisum
