GS: Hindi / English · Language questions stay in their original language.
120 questions · 120 marks · 2 hours
Choose one option per question.
Tap an option to check it, or open “See answer”.
Correct answer: (D) More than one of the above
Salvinia and Azolla are both heterosporous ferns, so the answer is ‘more than one’.
Correct answer: (B) Mn
Manganese (Mn) is needed for the photolysis of water in photosynthesis; it is part of the oxygen-evolving complex.
Correct answer: (C) 2,4-D
2,4-D is used as a weedicide—it kills dicot weeds selectively.
Correct answer: (E) None of the above
In angiosperms the functional megaspore develops into the embryo sac, which is not among the options.
Correct answer: (B) Restriction endonuclease
Restriction endonuclease is called ‘molecular scissors’, because it cuts DNA at a particular sequence.
Correct answer: (A) Thermus aquaticus
Taq polymerase comes from Thermus aquaticus, a thermophilic bacterium, which is why it works at the high temperatures of PCR.
Correct answer: (A) Six principles
The International Code of Botanical Nomenclature rests on six principles.
Correct answer: (D) More than one of the above
Capsicum, Atropa belladonna and Withania somnifera all belong to the Solanaceae, so the answer is ‘more than one’.
Correct answer: (B) Mg
At the centre of chlorophyll is magnesium (Mg), with the porphyrin ring around it.
Correct answer: (E) None of the above
In the nitrogen cycle nitrite is turned into nitrate by Nitrobacter; Nitrosomonas only turns ammonia into nitrite. So the answer is ‘None of these’.
Correct answer: (D) More than one of the above
Photorespiration involves the chloroplast and the mitochondrion besides the peroxisome, so more than one option is right.
Correct answer: (C) Ocean
The ocean is the most stable ecosystem, its volume being vast and its temperature and salinity changing very slowly.
Correct answer: (E) None of the above
Soil salinity is measured with a conductivity meter, which is not among the options.
Correct answer: (B) Doubling of chromosomes
Colchicine stops the spindle fibres from forming, so the chromosomes double and polyploid plants are raised.
Correct answer: (B) Selaginella
Selaginella shows both heterospory and leaves bearing a ligule.
Correct answer: (B) Cotton
The cotton fibre comes from hairs on the surface of the seed, and so is called a surface fibre. Jute and sunn hemp give stem fibres.
Correct answer: (E) None of the above
Quantasomes lie on the thylakoid membrane of the chloroplast and are taken to be the unit of photosynthesis—the chloroplast is not among the options.
Correct answer: (B) Hilum
The point at which the funicle joins the ovule is the hilum.
Correct answer: (A) Compositae
The capitulum inflorescence is characteristic of the Compositae, that is the Asteraceae—the sunflower, for instance.
Correct answer: (A) Thymine
RNA has no thymine; uracil takes its place.