11. Which is not a parasite? (UPSC Prelims 1984)
[A] Tick
[B] Housefly
[C] Bed bug
[D] Louse
Show Answer
Correct Answer: B [Housefly]
Notes:
Tick, beg bug and louse are parasitic insects that live on the skin of mammals or birds.
Housefly is not a parasite.
12. Genetic code is made up by the four-letter alphabet forming the pairs? (UPSC Prelims 1985)
[A] A—C, C—A, T—G, G—T
[B] A—G, G—A, C—A, T—C
[C] T—G, G—T, A—C, C—A
[D] A—T, T—A, C—G, G—C
Show Answer
Correct Answer: D [A—T, T—A, C—G, G—C]
Notes:
The four letters designating these bases (A, G, C, and T) are the alphabet of the genetic code. Each rung of the DNA molecule is contains a combination of two of these letters, one jutting out from each side. In this genetic code, A always combines with T, and C with G to make what is called a base pair.
13. Which one of the following diseases is least infectious? (UPSC Prelims 1991)
[A] Leprosy
[B] Tuberculosis
[C] Conjunctivitis
[D] Hepatitis
Show Answer
Correct Answer: D [Hepatitis]
Notes:
Most noninfectious causes of hepatitis are not contagious. Hepatitis caused by alcohol poisoning, medications, or toxins or poisons are not transmitted from person to person.
14. Epiphytes are plants which depend on other plants for? (UPSC Prelims 2001)
[A] food
[B] mechanical support
[C] shade
[D] water
Show Answer
Correct Answer: B [mechanical support]
Notes:
They are an important source of food for many species. Typically, the older parts of a plant will have more epiphytes growing on them. Epiphytes differ from parasites in that they grow on other plants for physical support and do not necessarily affect the host negatively.
15. 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.
16. Which one of the following is an example of a phospholipid?
[A] Steroid
[B] Cholesterol
[C] Lecithin
[D] Sterol
Show Answer
Correct Answer: C [Lecithin]
Notes:
Lecithin is a mixture of brown and yellow colored phospholipids that contain glycerol. It also acts as an emulsifier in many types of food.
17. What is the shape of enveloped viruses?
[A] icosahedral
[B] helical
[C] roughly spherical
[D] complex
Show Answer
Correct Answer: C [roughly spherical]
Notes:
The shape of enveloped viruses is roughly spherical. Enveloped virus have glyco-protein spikes that arise from their envelopes.
18. Which of the following are the most primitive vascular plants?
[A] Mosses
[B] Cycads
[C] Kelps
[D] Ferns
Show Answer
Correct Answer: D [Ferns]
Notes:
A fern is a member of a group of vascular plants. It reproduces by means of spores and has neither seeds nor flowers.
19. Into how many subgroups is the plant kingdom classified?
[A] Three
[B] Four
[C] Five
[D] Six
Show Answer
Correct Answer: C [Five]
Notes:
The plant kingdom has been classified into five subgroups: Thallophyta, Bryophyta, Pteridophyta, Gymnosperms, Angiosperms
20. Which of the following is analogous to mesosome of bacteria?
[A] Mitochondria of eukaryotes
[B] Golgi apparatus of eukaryotes
[C] Lysosomes of eukaryotes
[D] None of these
Show Answer
Correct Answer: A [Mitochondria of eukaryotes]
Notes:
analogous to mesosome of bacteria is Mitochondria of eukaryotes.
