11. In Mycorrhiza, symbiotic association occurs between which of the following organisms? (UPSC Prelims 1990)
[A] Bacteria and roots of higher plants
[B] Algae and roofs of orchids
[C] Fungi and roots of higher plants
[D] Protozoa and roots of higher plants
Show Answer
Correct Answer: C [Fungi and roots of higher plants]
Notes:
Mycorrhiza is a symbiotic association between a fungus and a plant. The term mycorrhiza refers to the role of the fungus in the plant’s rhizosphere, its root system.
12. Which one of the following is a modified stem? (UPSC Prelims 1996)
[A] Carrot
[B] Sweet Potato
[C] Coconut
[D] Potato
Show Answer
Correct Answer: D [Potato]
Notes:
Potato tuber bears buds in small pits known as eyes. Buds develops to branches. Some of the branches become green, erect and leafy stems that grow horizontally underground.
13. In which organ of the human body are the lymphocyte cells formed? (UPSC Prelims 2004)
[A] Liver
[B] Long bone
[C] Pancreas
[D] Spleen
Show Answer
Correct Answer: B [Long bone]
Notes:
Lymphocytes are the cells that determine the specificity of the immune response to infectious microorganisms and other foreign substances. In humans lymphocytes make up 25 to 33% of the total number of leukocytes. They are found in central lymphoid organs and tissues such as the spleen, tonsils and lymph nodes and large bones.
14. Consider the following statements with reference to the human body:
- The common bile duct releases its contents into the stomach.
- The pancreatic duct releases its contents into the duodenum.
Which of the above statements is/are correct? (UPSC Prelims 2006)
[A] I only
[B] II only
[C] Both I and II
[D] Neither I nor II
Show Answer
Correct Answer: B [II only]
Notes:
The common bile duct and the pancreatic duct both release their contents into the duodenum, not the stomach. The digestive enzyme (pancreatic juices) are released to the duodenum from the pancreatic duct.
15. Which among the following is a water soluble vitamin?
[A] Vitamin A
[B] Vitamin C
[C] Vitamin D
[D] Vitamin E
Show Answer
Correct Answer: B [Vitamin C]
Notes:
Except vitamins A, D, E and K, remaining all vitamins are water soluble vitamins. Vitamins A, D, E and K are fat soluble vitamins.
16. Who were the first scientists successfully isolated insulin in 1921?
[A] Frederick Banting and Charles Herbert Best
[B] Robert Hooke and Gregor Mendel
[C] Charles Darwin and Antonie van Leeuwenhoek
[D] Rachel Carson and Theodor Schwann
Show Answer
Correct Answer: A [Frederick Banting and Charles Herbert Best]
Notes:
Insulin was the first peptide hormone discovered. Canadians Frederick Banting and Charles Herbert Best were the first scientists successfully isolated insulin from the dog pancreas in 1921. They achieved this tremendous feat while working in Canada’s University of Toronto J.J.R. Macleod Laboratory.
17. Which among the following is NOT a major function of the plant hormone Abscisic Acid?
[A] Abscission of Leaves
[B] Inhibition of growth and maintenance of the dormancy of buds
[C] Inhibition of germination in dormant seeds
[D] All of them are major functions of Abscisic Acid
All of above are major functions of Abscisic acid
Show Answer
Correct Answer: A [Abscission of Leaves]
Notes:
This question is might have trapped almost all of you. The option A which etymologically linked to the question would trap you. We should note that Abscisic acid plays any significant role in leaf abscission is unfortunately not proved. The hormone is also called Dormin and its major functions are inhibition. But abscission of leaves is something better explained by Auxin-ethylene roles. Kindly surf the web and try to find out, if I am right. Inhibition of growth and maintenance of the dormancy of buds are the most striking effects of ABA. ABA activity alone is not enough to keep the dormancy of buds up in the long term though. Further, ABA is an efficient inhibitor of germination and occurs in high concentrations in dormant seeds. The role ABA has during the abscission of fruits and leaves is largely unknown. Though both cases seem to be governed by similar mechanisms (Auxin-Ethylene to a great extent) has ABA nearly no effect on the abscission of leaves while it shows a clear effect on fruit abscission. The role of Abscisic acid in abscission was a pharmacological artifact…applied AbA often induces ethylene biosynthesis.
18. Biometric is related to which of the following statement?
[A] the process of ageing, and the particular problems of old people
[B] heredity and variation
[C] body measurements and calculations related to human characteristics
[D] transmission of paternal traits to progeny
Show Answer
Correct Answer: C [body measurements and calculations related to human characteristics]
Notes:
Biometrics are calculations related to body measurements and human characteristics. Biometric authentication is used in computer science as a form of identification and access control.
19. The science of taxonomy is related to which of the following?
[A] Plant Classification
[B] Animal Classification
[C] Microorgranism
[D] None of these
Show Answer
Correct Answer: A [Plant Classification]
Notes:
The science of taxonomy is related to Plant Classification. Carl Linnaeus is the father of modern Taxonomy. Linnaeus, in his book System Naturae, has divided all living beings into two kingdoms – the plant kingdom and the animal kingdom.
20. Who among the following discovered the plasma membrane?
[A] Robert Hooke
[B] Albert von Kolliker
[C] George E. Palade
[D] Rudolf von Kölliker
Show Answer
Correct Answer: A [Robert Hooke]
Notes:
The plasma membrane is mainly composed of fatty-acid-based lipids and proteins. Robert Hooke discovered the plasma membrane.
