Mossess and ferns are found in moist and shady places because both
require presence of water for fertilization
do not need sunlight for photosynthesis
depend for their nutrition on microorganisms which can survive only at low temperature
cannot compete with sun-loving plants.
People recovering from long illness are often advised to include the alga Spirulina in their diet because it
makes the food easy to digest
is rich in proteins
has antibiotic properties
restores the intestinal microtlora
Azolla is used as a biofertilizer because it
multiplies very fast to produce massive biomass
has association of nitrogen - fixing Rhizobium
has association of nitrogen - fixing cyanobacteria
has association of mycorrhiza
In oogamy, fertilization involves :
a small non- motile female gamete and a large motile male gamete
a large motile female gamete and a small non-motile male gamete
a large non- motile female gamete and a small motile male gamete
a large non-motile female gamete and a small non-motile male gamete
In angiosperms, triple fusion results in the formation of:
zygotic nucleus
polar nucleus
secondary nucleus
primary endosperm nucleus
Read the following statements (IV) and answer the question which follows them
I. In liverworts, mosses and ferns gametophytes are free living.
II. Gymnosperms and some ferns are heterospores.
III. Sexual reproduction in Fucus, Volvox and Albugo is oogamous.
IV. The sporophyte in liverworts is more elaborate than that in mosses.
How many of the above statements are correct?
One
Two
Three
Four
The most common type of ovule found in angiosperms is
Anatropous ovule
Atropous ovule
Campylotropous ovule
Hemitropous ovule
A.
Anatropous ovule
Anatropous ovule is a completely inverted ovule turned back 180 degrees on its stalk. It is the most common type of ovule in angiosperms.
Campylotropous ovule refers to the body of the ovule that is curved or bent round so that the micropyle and chalaza so not lie in the same straight line.
Hemitropous ovule refers to the body of the ovule is placed transversely at right angles to the funicle. The micropyle and chalaza lie in one straight line.