11. Bile is secreted by which of the following organs? (UPSC Prelims 1985)
[A] Liver
[B] Gall bladder
[C] Kidney
[D] Pancreas
Show Answer
Correct Answer: A [Liver]
Notes:
Bile or gall is a dark green to yellowish brown fluid, produced by the liver of most vertebrates that aids the digestion of lipids in the small intestine. In humans, bile is produced continuously by the liver and stored and concentrated in the gallbladder.
12. Which of the following clearly define Lineage? (UPSC Prelims 1986)
[A] A straight line joining any two points on the globe
[B] The line of descendants of a particular ancestor
[C] The paleolithic age
[D] The linking of genes
Show Answer
Correct Answer: B [The line of descendants of a particular ancestor]
Notes:
A lineage is a single line of descent or linear chain within the tree while a clade is a monophyletic group, containing a single ancestor and all its descendants. Phylogenetic trees are typically created from DNA, RNA or protein sequence data.
13. Which of the following clearly define Pyrilla? (UPSC Prelims 1991)
[A] Disease of teeth and gums
[B] An insect pest
[C] A character of ancient Greek mythology
[D] A building heated by solar energy
Show Answer
Correct Answer: B [An insect pest]
Notes:
Adult Pyrilla perpusilla is a pale tawny-yellow, soft-bodied insect with head prominently drawn forward to form a snout. Both adults and nymphs are very active and suck sap from the leaves of sugarcane. On the slightest disturbance, they jump from leaf to leaf.
14. Which one of the following diseases is caused due to defective genes? (UPSC Prelims 1992)
[A] Ulcer
[B] Haemophilia
[C] Diabetes
[D] Cancer
Show Answer
Correct Answer: B [Haemophilia]
Notes:
Haemophilia is a mostly inherited genetic disorder that impairs the body’s ability to make blood clots, a process needed to stop bleeding. This results in people bleeding longer after an injury, easy bruising, and an increased risk of bleeding inside joints or the brain.
15. Ticks and mites belongs to which of the following classes? (UPSC Prelims 2002)
[A] Arachnids
[B] Crustaceans
[C] Insects
[D] Myriapods
Show Answer
Correct Answer: A [Arachnids]
Notes:
The order Acarina (class Arachnida) includes mites and ticks. Members of this order differ from other arachnids in that the body is not segmented, and the cephalothorax and abdomen are combined into one body region. Larval mites and ticks have three pairs of legs, whereas nymphs and adults have four pairs.
16. 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.
17. Which among the following organs secrete bile juice?
[A] Liver
[B] Pancreas
[C] Stomach
[D] Large intestine
Show Answer
Correct Answer: A [Liver]
Notes:
Bile is a digestive juice secreted by the liver and it aids in the digestion of food. Many waste products are eliminated from the body through bile.
18. What is another name for Koshland’s theory of enzyme action?
[A] Reduced fit theory
[B] Induced fit theory
[C] Enzyme coenzyme theory
[D] Lock and key theory
Show Answer
Correct Answer: B [Induced fit theory]
Notes:
Induced fit theory is also known as Koshland’s theory of enzyme action. It describes the enzyme-substrate interaction.
19. What is the shape of enveloped viruses?
[A] icosahedral
[B] helical
[C] roughly spherical
[D] complex
Show Answer
Correct Answer: C [roughly spherical]
Notes:
The shape of enveloped viruses is roughly spherical. Enveloped virus have glyco-protein spikes that arise from their envelopes.
20. Covered smut of Sorghum is caused by which of the following?
[A] Sphacelotheca sorghi
[B] Sphacelotheca cruenta
[C] Sphacelotheca reiliana
[D] Tolyposporium ehrenbergii
Show Answer
Correct Answer: A [Sphacelotheca sorghi]
Notes:
Sporisorium sorghi is a fungus in the family of Ustilaginaceae. It is a plant pathogen that causes the covered scum of sorghum.
