11. Why man cannot digest cellulose whereas cows can do so? (UPSC Prelims 1992)
[A] Their gut contains certain bacteria capable of digesting cellulose
[B] They have a many-chambered stomach
[C] They have efficient grinding molars
[D] They produce enzyme cellulose which can digest cellulose
Show Answer
Correct Answer: A [Their gut contains certain bacteria capable of digesting cellulose]
Notes:
Unlike cows for example don’t have the necessary bacteria in their intestines that make the enzymes necessary to breakdown the 1-4 beta glucose bonds. So we cannot break down cellulose into its constituent glucose molecules as we do with starch.
12. In eye donation, which one of the following parts of donor’s eye is utilized? (UPSC Prelims 1999)
[A] Iris
[B] Lens
[C] Cornea
[D] Retina
Show Answer
Correct Answer: C [Cornea]
Notes:
Generally blindness is caused by the dryness and hardness of cornea. Cornea is a clear layer which helps passing of light. It is an outer layer and can be transfer from one person to another.
13. Fertility of soil can be improved by which of the following methods? (UPSC Prelims 2000)
[A] Removing dead earthworms
[B] Adding dead earthworms
[C] Adding living earthworms
[D] Removing living earthworms and adding dead earthworms
Show Answer
Correct Answer: C [Adding living earthworms]
Notes:
Worms help to increase the amount of air and water that gets into the soil. They break down organic matter, like leaves and grass into things that plants can use. When they eat, they leave behind castings that are a very valuable type of fertilizer. Earthworms are like free farm help.
14. Which gas is absorbed by the plants during photosynthesis?
[A] Oxygen
[B] Carbon dioxide
[C] Nitrogen
[D] Hydrogen
Show Answer
Correct Answer: B [Carbon dioxide]
Notes:
During the process of photosynthesis, plants take carbon dioxide and water and produces oxygen and glucose in the presence of light.
15. Who is known as the ‘God of plants’?
[A] Soma
[B] Varuna
[C] Rudra
[D] Indra
Show Answer
Correct Answer: A [Soma]
Notes:
Soma is also known as the God of plants or the king of gods or the special god of the Brahmanas. All the hymns of the eleventh mandal are assigned to him. Aryans considered Himalaya as the source of the soma plant.
16. Which of the following is the taxonomic family of humans?
[A] Hominidae
[B] Haplorhini
[C] Primates
[D] Homini
Show Answer
Correct Answer: A [Hominidae]
Notes:
The genus of the human being today is called Homo and the man today is called as Homo sapiens. From simple life forms that were unicellular to the development of multicellular organisms gave rise to the vertebrates. The family to which human beings belong is called Hominidae. It was in the Miocene age that the family Hominidae split from the Pongidae(apes) family.
17. What is the famous Bombyx Mori, a variety of?
[A] Honeybee
[B] Cotton
[C] Earthworm
[D] Silk
Show Answer
Correct Answer: D [Silk]
Notes:
Sericulture – It refers to the rearing of silk worms and obtaining silk from them. It involves raising a feed crop, chiefly mulberry leaves, and tending to silk worms and obtaining silk fibre from the cocoons produced by the worms.
Varieties – There are a number of varieties of worm reared for silk production, the most important variety being Bombyx mori.
18. Which of the following biomolecules is more widely distributed in the cell?
[A] Chloroplast
[B] RNA
[C] DNA
[D] Spaherosomes
Show Answer
Correct Answer: B [RNA]
Notes:
DNA and RNA are two types of nucleic acids. DNA is converted into RNA by the process of transcription. The three types of RNA are m-RNA, t-RNA and r-RNA.
19. 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.
20. Which of the following may be most likely to be missing from a gram-positive bacterium?
[A] Penicillin-binding protein
[B] Peptidoglycan
[C] Lipopolysaccharide
[D] Phospholipid bilayer membrane
Show Answer
Correct Answer: C [Lipopolysaccharide]
Notes:
Gram-negative bacteria are surrounded by a thin peptidoglycan cell wall. It itself is surrounded by an outer membrane containing lipopolysaccharides.
