11. Which of the following is the most common wheat disease in India?
[A] Green ear
[B] Smut
[C] Loose smut
[D] Rust
Show Answer
Correct Answer: D [Rust]
Notes:
Wheat leaf rust is a fungal disease that affects wheat, barley and rye stems, leaves and grains. Its infections can lead up to 20% yield loss, which is exacerbated by dying leaves, which fertilize the fungus. The pathogen of rust is Puccinia rust fungus.
12. Which of the following functions is not performed by Vitamins in the body? (UPSC Prelims 1982)
[A] They act as a source of energy
[B] The act as stimulant in the growth of the body
[C] They act as agent in regulating the chemical processes in the body metabolism
[D] All of the above
Show Answer
Correct Answer: A [They act as a source of energy]
Notes:
Vitamins are considered essential nutrients because they perform hundreds of roles in the body. They help shore up bones, heal wounds, and bolster your immune system. They also convert food into energy, and repair cellular damage. They do not act as a source of energy.
13. Water hyacinth is related to which of the following genus? (UPSC Prelims 1988)
[A] Lemna
[B] Pistia
[C] Eichhornia
[D] None of these
Show Answer
Correct Answer: C [Eichhornia]
Notes:
Water hyacinth, an aquatic plant of the genus Eichhornia of the pickerelweed family, consisting of about five species is native primarily to tropical America. Some species float in shallow water; others are rooted in muddy stream banks and lakeshores.
14. Why there are more anti-bacterial drugs than anti-viral drugs? (UPSC Prelims 1989)
[A] Bacterial diseases are intra-cellular
[B] Viral diseases are intra-cellular
[C] Virus is smaller than bacteria
[D] Drugs can penetrate bacteria more effectively
Show Answer
Correct Answer: B [Viral diseases are intra-cellular]
Notes:
Viruses infect all sorts of cells, from bacteria to human cells, but for the most part tend to be host specific. For example, the tobacco mosaic virus infects certain plants; the rabies virus infects only mammals; and the AIDS virus, HIV, infects only certain human blood cells.
15. The highest fat content is found in the milk of which of the following animals? (UPSC Prelims 1991)
[A] Buffalo
[B] Cow
[C] Camel
[D] Reindeer
Show Answer
Correct Answer: A [Buffalo]
Notes:
Buffalo milk has the highest fat content, which is on average twice as high as that of cow milk. The fat-to-protein ratio in buffalo milk is about 2:1.
16. Who among the following first discovered the process of digestion?
[A] Nehemiah Grew
[B] William Beaumont
[C] Alister Hardy
[D] None of these
Show Answer
Correct Answer: B [William Beaumont]
Notes:
William Beaumont was a US Army surgeon who was the first to observe and study human digestion occurring in the stomach.
17. Which of the following can be done in the cultivation of plant viruses?
[A] tissue culture
[B] cultures of separated cells
[C] whole plants
[D] all of these
Show Answer
Correct Answer: D [all of these]
Notes:
The cultivation of plant viruses can be done in tissue culture, cultures of separated cells and whole plants.
18. Virus size is usually measured by__?
[A] centimeters
[B] micrometers
[C] nanometers
[D] millimeters
Show Answer
Correct Answer: C [nanometers]
Notes:
Virus size is usually measured by nanometers. Most viruses vary in diameter from 20 nanometers (nm; 0.0000008 in) to 250–400 nm. The largest viruses have a diameter of about 500 nm and a length of about 700–1,000 nm.
19. In pteridophytes, which of the following is the dominant generation?
[A] gametophytic
[B] haploid
[C] diploid
[D] triploid
Show Answer
Correct Answer: C [diploid]
Notes:
In pteridophytes, the dominant is the diploid sporophytic generation because it develops from the diploid zygote.
20. What is the common name of pteridophytes?
[A] Ferns
[B] conifers
[C] flowering plant
[D] None of these
Show Answer
Correct Answer: A [Ferns]
Notes:
The common name of pteridophytes is Ferns. Ferns are vascular plants that differ from lycophytes in having true leaves that are often pinnate.
