UGC NET CS 2004 Dec-Paper-2
July 25, 2024DSSSB PGT 2021
| Question 37 |
Read the following information carefully and answer the given questions.
Bioluminescence, emission of light by an organism or by a laboratory biochemical system derived from an organism. It could be the ghostly glow of bacteria on decaying meat or fish, the himmering radiance of protozoans in tropical seas, or the flickering signals of fireflies. The phenomenon ccurs sporadically in a wide range of protists and animals, from bacteria and fungi to insects, marine nvertebrates, and fish, but it is not known to exist naturally in true plants or in amphibians, reptiles, birds, or mammals.
Bioluminescence results from a chemical reaction (chemiluminescence) in which the conversion of chemical energy to radiant energy is direct and virtually 100 percent efficient; i.e., very little heat is given off in the process. For that reason, the emission is called cold light or luminescence.
The functional role of bioluminescence in lower organisms such as bacteria, dinoflagellates, and fungi is difficult to discern. Partly because the glow of luminous bacteria is extinguished when oxygen is removed, it has been suggested that the bioluminescent reaction was originally used to remove oxygen toxic to primitive types of bacteria that developed when oxygen was absent or very rare in Earth’s atmosphere. The metabolic reaction that combines the oxygen with a reducing substance (luciferin) liberates sufficient energy to excite a molecule in the organism to emit visible radiation. Most of those luminous primitive organisms subsequently developed systems of using oxygen, but they have retained the luminescent capability as parts of related metabolic pathways or for some survival value that luminescence may confer on the organism
Bioluminescence, emission of light by an organism or by a laboratory biochemical system derived from an organism. It could be the ghostly glow of bacteria on decaying meat or fish, the himmering radiance of protozoans in tropical seas, or the flickering signals of fireflies. The phenomenon ccurs sporadically in a wide range of protists and animals, from bacteria and fungi to insects, marine nvertebrates, and fish, but it is not known to exist naturally in true plants or in amphibians, reptiles, birds, or mammals.
Bioluminescence results from a chemical reaction (chemiluminescence) in which the conversion of chemical energy to radiant energy is direct and virtually 100 percent efficient; i.e., very little heat is given off in the process. For that reason, the emission is called cold light or luminescence.
The functional role of bioluminescence in lower organisms such as bacteria, dinoflagellates, and fungi is difficult to discern. Partly because the glow of luminous bacteria is extinguished when oxygen is removed, it has been suggested that the bioluminescent reaction was originally used to remove oxygen toxic to primitive types of bacteria that developed when oxygen was absent or very rare in Earth’s atmosphere. The metabolic reaction that combines the oxygen with a reducing substance (luciferin) liberates sufficient energy to excite a molecule in the organism to emit visible radiation. Most of those luminous primitive organisms subsequently developed systems of using oxygen, but they have retained the luminescent capability as parts of related metabolic pathways or for some survival value that luminescence may confer on the organism
Sub Question No.:
Which of the following words best expresses the true meaning of the word ‘confer’?
| Consult | |
| Hole | |
| Refuse | |
| Withhold |
Correct Answer: A
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