11. Which one of the following diseases is least infectious? (UPSC Prelims 1991)
[A] Leprosy
[B] Tuberculosis
[C] Conjunctivitis
[D] Hepatitis
Show Answer
Correct Answer: D [Hepatitis]
Notes:
Most noninfectious causes of hepatitis are not contagious. Hepatitis caused by alcohol poisoning, medications, or toxins or poisons are not transmitted from person to person.
12. Which one of the following is cultivated by transplanting seedlings? (UPSC Prelims 1997)
[A] Maize
[B] Sorghum
[C] Onion
[D] Soyabean
Show Answer
Correct Answer: C [Onion]
Notes:
Onions can be grown from seeds, seedlings and bulblets. Proper nursery management and transplanting are important operations in the onion crop. About 0.05 hectare nursery bed area is enough for getting seedlings to transplant in one hectare.
13. Which of the following defines the process of Metastasis? (UPSC Prelims 2001)
[A] cells divide rapidly under the influence of drugs
[B] cancer cells spread through the blood or laymphatic system to other sites or organs
[C] the chromosomes in cell nuclei are attached to the spindle before moving to the anaphase poles
[D] cancer cells are successfully inhibited to divide any further
Show Answer
Correct Answer: B [cancer cells spread through the blood or laymphatic system to other sites or organs]
Notes:
Metastasis is a complex process that involves the spread of a tumor or cancer to distant parts of the body from its original site. The cancerous cells are sloughed from the tumours and reach distant sites through blood, and whenever they get lodged in the body, they start a new tumour there. This property called metastasis is the most feared property of malignant tumours.
14. With reference to the blood in a normal person, which one of the following statements is correct? (UPSC Prelims 2002)
[A] Compared to arteries, veins are less numerous and hold less of the body’s blood at any given time
[B] Blood cells constitute about 70 per cent of the total volume of the blood
[C] White Blood Cells (WBC) are made by lymph nodes only
[D] The blood has more platelets than WBC
Show Answer
Correct Answer: D [The blood has more platelets than WBC]
Notes:
Blood has more platelets than corpuscles. A microlitre of blood contains 5,000-10,000 of White blood cells (WBC) and 150,000-500,000 platelets.
15. In the context of the organic evolution, the loss of limbs of snakes is explained by which of the following phenomenon? (UPSC Prelims 2002)
[A] Use and disuse of organs
[B] adaptation to living in burrows
[C] natural selection
[D] inheritance of acquired characters
Show Answer
Correct Answer: A [Use and disuse of organs]
Notes:
In organic evolution, Lamarck believed that any particular part of the body that is put into more frequent use has tendency to develop stronger and better while that part of body which is put into less or no use has tendency to gradually disappear. So, loss of limbs in snake is an example of use and disuse of organs.
16. Which among the following branches of science deals with the scientific study of interaction of soils with vegetative matter?
[A] Pedology
[B] Petrology
[C] Hydrology
[D] Edaphology
Show Answer
Correct Answer: D [Edaphology]
Notes:
Edaphology is one of the two branches of soil sciences which deals with the scientific study of influence of soils on the vegetative matter such as plants.
17. In photosynthesis, light energy is converted into which form of energy?
[A] Electrical energy
[B] Kinetic energy
[C] Chemical energy
[D] Potential energy
Show Answer
Correct Answer: C [Chemical energy]
Notes:
In the process of photosynthesis, the energy from solar light is converted into the chemical energy.
18. Which among the following is an optimum temperature for wheat seed germination?
[A] 11-15 deg celsius
[B] 15-25 deg celsius
[C] 10-12 deg celsius
[D] 20-22 deg celsius
Show Answer
Correct Answer: C [10-12 deg celsius]
Notes:
10-12 deg celsius is the optimum temperature for wheat germination. 25-30 deg celsius is the optimum temperature for crop growth.
19. What are plants without seeds having vascular tissue?
[A] Gymnosperms
[B] Bryophytes
[C] Angiosperm
[D] Pteridophytes
Show Answer
Correct Answer: D [Pteridophytes]
Notes:
Pteridophyte is a type of vascular plant, which spreads spores. Pteridophytes produce neither flowers nor seeds, they are sometimes referred to as “cryptogams”.
20. Which of the following is not a part of the sexual cycle of fungi?
[A] Meiosis
[B] Karyogamy
[C] Mitosis
[D] Plasmogamy
Show Answer
Correct Answer: C [Mitosis]
Notes:
Mitosis is a process where a single cell divides into two identical daughter cells.
