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:
The housefly is generally a free-living scavenger rather than a parasite, although it can carry pathogens mechanically. Ticks, bedbugs and lice obtain food from animal hosts. Ticks are arachnids, not insects.
12. Through which of the following mechanisms genes control the activity of living organisms? (UPSC Prelims 1986)
[A] Photosynthesis
[B] Protein synthesis
[C] Vitamins
[D] Hormones
Show Answer
Correct Answer: B [Protein synthesis]
Notes:
Protein-coding genes influence cell activities through the production of proteins, including enzymes and structural proteins. Messenger RNA carries the coding information to ribosomes. Some genes produce functional RNA rather than proteins, so protein synthesis is not the sole function of every gene.
13. The saliva helps in the digestion of which of the following materials? (UPSC Prelims 1988)
[A] Starch
[B] Proteins
[C] Fibers
[D] Fats
Show Answer
Correct Answer: A [Starch]
Notes:
The digestive functions of saliva include moistening food, and helping to create a food bolus, so it can be swallowed easily. Saliva contains the enzyme amylase that breaks some starches down into maltose and dextrin. Thus, digestion of food occurs within the mouth, even before food reaches the stomach.
14. 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.
15. In a bisexual flower, if androecium and gynaecium mature at different times, what is the name given to the phenomenon? (UPSC Prelims 2004)
[A] Dichogamy
[B] Herkogamy
[C] Heterogamy
[D] Monogamy
Show Answer
Correct Answer: A [Dichogamy]
Notes:
Dichogamy The condition in which the male and female reproductive organs of a flower mature at different times, thereby ensuring that self-fertilization does not occur.
16. Which among the following is the method of growing plants in the absence of soil?
[A] Hydrology
[B] Hydrotectonics
[C] Hydroponics
[D] Hydrochronology
Show Answer
Correct Answer: C [Hydroponics]
Notes:
The method of growing plants in the absence of soil is called as hydroponics. The required suppliments to the plants are supplied through the mineral nutrient solutions.
17. Pollination by which among the following is called as ornithophily?
[A] Rodents
[B] Aquatic animals
[C] Ants
[D] Birds
Show Answer
Correct Answer: D [Birds]
Notes:
Ornithophily refers to the pollination assisted by the birds. Ornithology is a branch of science which studies about birds. Dr. Salim Ali is a famous Indian ornithologist.
18. Which branch of medicine deals with the scientific study of the structure of teeth and diseases associated with it?
[A] Virology
[B] Opthalmology
[C] Cosmology
[D] Odontology
Show Answer
Correct Answer: D [Odontology]
Notes:
Odontology is a branch of medicine which deals with the structure and diseases related to the teeth.
19. The Study of Bryophytes & pteridophytes is known by Which terms?
[A] Cytology
[B] Bryology
[C] Mycology
[D] Pomology
Show Answer
Correct Answer: B [Bryology]
Notes:
Bryology is the branch of botany that deals with the scientific study of bryophytes such as mosses, liverworts, and hornworts.
20. The name of Theodor Schwann is associated with the discovery of which of the following?
[A] enzyme pepsin
[B] glial cells in nerves
[C] microorganisms play in alcohol fermentation
[D] All of the above
Show Answer
Correct Answer: D [All of the above]
Notes:
Schwann discovered the enzyme pepsin and discovered glial cells in nerves – these are now known as Schwann cells. He also identified the role of microorganisms in alcohol fermentation.
