Which of the following groups of algae produces algin?
Phaeophyceae and Chlorophyceae
Rhodophyceae and Phaeophyceae
Chlorophyceae and Rhodophyceae
Phaeophyceae only
Assertion: Presence of large amounts of nutrients in water body causes excessive growth of planktonic algae.
Reason: It is due to biomagnification.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
C.
If assertion is true but reason is false.
Presence of large amounts of nutrients in water causes excessive growth of planktonic (free-floating) algae, called an algal bloom which imparts a distinct colour to the water bodies. Algal blooms cause deterioration of the water quality and fish mortality. Biomagnification refers to increase in concentration of the toxicant at successive trophic levels.
Assertion : Sphagnum is slowly carbonised, compressed and fossilised over thousands of years to produce a dark spongy mass called peat.
Reason : Peat helps to keep soil porous and it also improves water holding capacity of the soil.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false
Which of the following is not an invasive species?
Parthenium hysterophorus
Nelumbo (lotus)
Lantana camara
Eichhornia crassipes
In which of the following sets of organisms, does the external fertilization occur?
Echinodermata and mosses
Hemichordata and ferns
Amphibians and algae
Reptiles and gymnosperms
Occurrence of triploid (3n) primary endosperm nucleus is a characteristic feature of
Algae
Gymnosperms
Angiosperms
Bryophytes
Assertion: The leaves in gymosperms are well adapted to with stand extremes of temperature, humidity and wind.
Reason: Unlike bryophytes and pteridophytes, in gymnosperms the male and female gametophytes do not have an independent free-living existence.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
Assertion: In basidiomycetes, basidiospores are produced endogenously in the basidium.
Reason: In ascomycetes, ascospores are produced exogenously in ascus.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
Gametophyte and sporophyte are independent of each other in which of the following groups?
Pteridophytes
Angiosperms
Gymnosperms
Bryophytes