11. The Trans-fats cause problems in human body because__:
[A] The fat molecules contain high energy that cause oxidation of the tissues
[B] The structure of the fat molecules is such that more molecules can fit in lesser space
[C] The fat molecules contain lesser energy and can not be used so easily
[D] None of the above reasons
Show Answer
Correct Answer: B [ The structure of the fat molecules is such that more molecules can fit in lesser space]
Notes:
Trans unsaturated fats are particularly risky because the double bond stereochemistry allows the fat molecules to assume a linear conformation, which leads to efficient packing (i.e., plaque formation).
12. Which process enables the Peepal tree to release oxygen at night?
[A] Crassulacean Acid Metabolism
[B] C3 Photosynthesis
[C] C4 Photosynthesis
[D] Carbon cycle re-balancing
Show Answer
Correct Answer: A [Crassulacean Acid Metabolism]
Notes:
The Peepal tree uses Crassulacean Acid Metabolism (CAM) photosynthesis, allowing CO₂ uptake at night and oxygen release, a trait seen in some succulents and epiphytes to minimize water loss. CAM enables the Peepal to continue gas exchange during the night, unlike typical C3 or C4 plants.
13. With reference to cellular organization, consider the following:
- Fungi
- Bacteria
- Algae
- Protozoa
Which of the above possess eukaryotic cells?
[A] Only 3 and 4
[B] Only 1 and 2
[C] 1, 2, 3 and 4
[D] Only 1, 3 and 4
Show Answer
Correct Answer: D [Only 1, 3 and 4]
Notes:
Eukaryotic cells feature a true nucleus and membrane-bound organelles. Fungi, algae, and protozoa are all eukaryotic organisms. In contrast, bacteria are prokaryotic, lacking a true nucleus and such organelles. Therefore, only Fungi, Algae, and Protozoa (1, 3 and 4) possess eukaryotic cells, while bacteria do not.
14. Which of the following are the postulates of Darwin’s theory of evolution?
[A] Within any population, there is natural variation.
[B] Even though all species produce a large number of offsprings, populations remain fairly constant
[C] The struggle for survival within populations eliminates the unfit individuals.
[D] All the above are correct
Show Answer
Correct Answer: D [All the above are correct]
Notes:
Darwin’s theory of evolution can be described as: within any population, there is natural variation. Some individuals have more favourable variations than others. Even though all species produce a large number of offsprings, populations remain fairly constant naturally. The struggle for survival within populations eliminates the unfit individuals. This is called natural selection.
15. Which one of the following is secreted by Pancreas and regulates the amount of sugar in the body? (UPSC Prelims 1980).
[A] Renin
[B] Creatin
[C] Vitamin
[D] Insulin
Show Answer
Correct Answer: D [Insulin]
Notes:
Insulin and glucagon are hormones secreted by islet cells within the pancreas. They are both secreted in response to blood sugar levels, but in opposite fashion. Insulin is normally secreted by the beta cells of the pancreas. Glucagon raises blood glucose levels by stimulating the liver to metabolize glycogen into glucose molecules and to release glucose into the blood. Insulin is a hormone that regulates blood sugar levels.
16. Which of the following crops has the highest photosynthetic activity?
[A] Cotton
[B] Sugarcane
[C] Rice
[D] Wheat
Show Answer
Correct Answer: B [Sugarcane]
Notes:
Among the above all, the sugarcane has the highest photosynthetic activity. Photosynthesis is a chemical process that occurs in many forms of bacteria and virtually all plants, including aquatic plants and algae. The rate of photosynthesis in a plant is dependent on the environmental changes, as well as to intrinsic features of plant. The photosynthetic rate in sugarcane is directly related with the variation of solar radiation during the day.
17. Which of the following features of DNA makes in uniquely suited to store and transmit genetic information from generation to generation? (UPSC Prelims 2001)
[A] Complementarity of the two stands
[B] Double helix
[C] Number of base-pairs per turn
[D] Sugar-phosphate backbone
Show Answer
Correct Answer: A [Complementarity of the two stands]
Notes:
Complementary base pairing in the DNA double helix (with its complementary DNA strands) describes the manner in which deoxyribose- nucleotides bind to each other. Essentially it means that the bases are arranged along the molecule such that the chains fit together snugly so as to be lightly secured by hydrogen bonds.
18. Which of the following define the hormone insulin? (UPSC Prelims 2004)
[A] Glycolipid
[B] Fatty acid
[C] Peptide
[D] Stero
Show Answer
Correct Answer: C [Peptide]
Notes:
Insulin is a protein chain or peptide hormone. There are 51 amino acids in an insulin molecule. It has a molecular weight of 5808 Da. Insulin is produced in the islets of Langerhans in the pancreas.
19. Which among the following blood groups is referred as the universal donor blood group?
[A] O -ve
[B] O +ve
[C] AB -ve
[D] AB +ve
Show Answer
Correct Answer: A [O -ve]
Notes:
The person with O-ve blood group is considered as the universal donor. Whereas a person with O +ve is not a universal donor as O +ve consists of Rh(Rhesus) factor which makes it incompatible for Rh -ve bloods.
20. Hugo de Vries is related to which of the following theory of biology?
[A] aquatic ape theory
[B] modern anatomy
[C] Mutation Theory
[D] theory of evolution
Show Answer
Correct Answer: C [Mutation Theory]
Notes:
Hugo de Vries is a Dutch botanist and geneticist who pioneered the experimental study of biological evolution. His rediscovery of Gregor Mendel’s principles of heredity and his theory of biological mutation in 1900.
