11. Natural rubber is a plant product which is chemically known by which of the following names? (UPSC Prelims 1992)
[A] Mucilage
[B] Gum
[C] Latex
[D] Resin
Show Answer
Correct Answer: C [Latex]
Notes:
The word latex means only natural rubber. Natural rubber is made from the white sap of some trees such as the Hevea brasiliensis (Euphorbiaceae). Other elastomers, called synthetic rubbers, are made by chemical processes.
12. Which of the following is the name given to the complete conversion of glucose In the presence of oxygen into carbon dioxide and water with release of energy? (UPSC Prelims 1998)
[A] aerobic respiration
[B] anaerobic respiration
[C] glycolysis
[D] hydrolysis
Show Answer
Correct Answer: A [aerobic respiration]
Notes:
In the cell, the food (glucose) is broken down into carbon dioxide and water using oxygen. When breakdown of glucose occurs with the use of oxygen it is called aerobic respiration. With the formula: (C6H12O6) + 6O2 = (6CO2) + 6H2O + E.
13. Mammology is the branch of science related to the study of?
[A] mammals
[B] breasts
[C] mollusks
[D] none of these
Show Answer
Correct Answer: A [mammals]
Notes:
Mammology is a branch of biology that deals with the study of mammals.
14. What is a common feature of archaebacteria?
[A] Structure of cell membrane
[B] Structure of cell wall
[C] Has fatty acid synthetase
[D] Structure of flagellin protein
Show Answer
Correct Answer: C [Has fatty acid synthetase]
Notes:
Archaebacteria are primitive bacteria that have a cell wall consisting of branched lipids that help them to endure adverse conditions.
15. The biological nature of the virus came from studies by the Russian scientist ____ in 1892 and by the Dutch scientist ____ in 1898.
[A] Dmitry I. Ivanovsky, Martinus W. Beijerinck
[B] Martinus W. Beijerinck, Dmitry I. Ivanovsky
[C] Félix H. d’Hérelle, Frederick W. Twort
[D] Frederick W. Twort, Félix H. d’Hérelle
Show Answer
Correct Answer: A [Dmitry I. Ivanovsky, Martinus W. Beijerinck]
Notes:
The biological nature of viruses was discovered in 1892 by the Russian scientist Dmitry I. Ivanovsky and in 1898 the Dutch scientist Martinus W. Beijerinck’s studies.
16. Which Viruses are Relatively Thermostable?
[A] Human immunodeficiency virus
[B] Rubella virus
[C] Hepatits A virus
[D] Influenza virus
Show Answer
Correct Answer: C [Hepatits A virus]
Notes:
Hepatitis A virus are Relatively Thermostable. A highly contagious liver infection caused by the hepatitis A virus.
17. Which of the following is not an example of bryophytes?
[A] Marchantia
[B] Funaria
[C] Sphagnum
[D] Selaginella
Show Answer
Correct Answer: D [Selaginella]
Notes:
Selaginella is not an example of bryophytes. Selaginella, Equisetum, Pteris, etc.are examples of Pteridophyta.
18. What is involved in the release of pollen grains?
[A] Pectin and cellulose
[B] Lignocellulose
[C] Pollenkit
[D] Sporopollenin
Show Answer
Correct Answer: D [Sporopollenin]
Notes:
Sporopollenin is the most chemically inert organic polymer. It is a major component of the tough outer (outer) walls of plant spores and pollen grains.
19. What does Prothallus represent?
[A] sporophytic phase in a fern
[B] gametophytic phase in a fern
[C] sporophytic phase in a gymnosperm
[D] gametophytic phase in a gymnosperm
Show Answer
Correct Answer: B [gametophytic phase in a fern]
Notes:
Prothallus represents the gametophytic phase in a fern. The diploid sporophyte represents a major, independent, photosynthetic, and vascular plant body.
20. Which one of the following is the innermost part of a flower and the female reproductive organ?
[A] Stamen
[B] Pistil
[C] Stigma
[D] Sepals
Show Answer
Correct Answer: B [Pistil]
Notes:
The pistil is the innermost part of a flower and the female reproductive organ consists of three parts – the stigma, the style and the ovary collectively known as the pistil.
