11. Typhoid fever is caused by which of the following?
[A] Allergy
[B] Fungus
[C] Bacteria
[D] Virus
Show Answer
Correct Answer: C [Bacteria]
Notes:
Typhoid fever is a systemic infection caused by bacteria Salmonella typhi, usually through ingestion of contaminated food or water. The acute illness is characterized by prolonged fever, headache, nausea, loss of appetite, and constipation or sometimes diarrhoea.
12. Which of the following micro-organism causes diseases like polio and chicken pox?
[A] Bacteria
[B] Protozoa
[C] Algae
[D] Virus
Show Answer
Correct Answer: D [Virus]
Notes:
Poliomyelitis or polio is an infection caused by the polio virus. It is a serious disease affecting a person’s brain and spinal cord. Chickenpox, also known as varicella, is a highly contagious disease caused by the initial infection with varicella zoster virus (VZV).
13. The temperature for pasteurisation of milk is selected so as to fulfil which among the following purposes? (UPSC Prelims 1979).
[A] Kill the micro-organisms
[B] Kill all bacteria
[C] Store it for long time without coagulation
[D] Kill the micro organisms and other harmful bacteria
Show Answer
Correct Answer: D [Kill the micro organisms and other harmful bacteria]
Notes:
Pasteurization is the process of heating milk up and then quickly cooling it down to eliminate certain bacteria and all other microorganisms. More common is heating milk up to at least 161.6 degrees Fahrenheit for 15 seconds. There are following methods that are most commonly used:
• High Temperature, Short Time (HTST) method – This method requires that the milk be held at 161 degrees for 16 seconds.
• Ultra-Pasteurization (UP) – This is the type of pasteurization that you will most commonly see on cartons of milk, half-and-half and heavy cream.
14. Camel uses its hump for which of the following purposes? (UPSC Prelims 1993)
[A] Storing water
[B] storing fat
[C] balancing the body during walking in desert sand
[D] temperature regulation
Show Answer
Correct Answer: B [storing fat]
Notes:
A camel’s hump does not hold water at all – it actually stores fat. The camel uses it as nourishment when food is scarce. If a camel uses the fat inside the hump, the hump will become limp and droop down. The hump is not used for water storage, but camels can go for long periods of time without water.
15. It is possible to produce seedless tomato fruits by which of the following processes? (UPSC Prelims 1996)
[A] Applying trace elements in tomato fields
[B] spraying mineral solution on plants
[C] spraying hormones on flowers
[D] applying fertilizers containing radioactive elements
Show Answer
Correct Answer: C [spraying hormones on flowers]
Notes:
Seed and fruit development are intimately related processes controlled by internal signals and environmental cues. One method to produce seedless fruit is to develop plants able to produce fruits independently from pollination and fertilization of the ovules.
16. The sequencing of the entire genome (the totality of all genes) of an organism was completed in 1996. Which one of the following was that organism? (UPSC Prelims 1997)
[A] Albino mouse
[B] yeast
[C] human being
[D] Plasmodium vivax
Show Answer
Correct Answer: D [Plasmodium vivax]
Notes:
Plasmodium vivax is a protozoal parasite and a human pathogen. This parasite is the most frequent and widely distributed cause of recurring malaria.
17. Which of the following contain a protein named Alpha-keratin? (UPSC Prelims 1997)
[A] Blood
[B] skin
[C] wool
[D] eggs
Show Answer
Correct Answer: B [skin]
Notes:
Alpha-keratin, or α-keratin, is a type of keratin found in vertebrates. This protein is the primary component in hair, horns, mammalian claws, nails and the epidermis layer of the skin. α-keratin is a fibrous structural protein, meaning it is made up of amino acids that form a repeating secondary structure.
18. Which among the following is an optimum temperature for wheat seed germination?
[A] 11-15 deg celsius
[B] 15-25 deg celsius
[C] 10-12 deg celsius
[D] 20-22 deg celsius
Show Answer
Correct Answer: C [10-12 deg celsius]
Notes:
10-12 deg celsius is the optimum temperature for wheat germination. 25-30 deg celsius is the optimum temperature for crop growth.
19. What is Rancidity?
[A] Deterioration of Fat
[B] Deterioration of Glucose
[C] Deterioration of Protein
[D] Deterioration of Vitamins
Show Answer
Correct Answer: A [Deterioration of Fat]
Notes:
The process of oxidation of oily and Fatty food, which changes its taste and smell is known as Rancidity. Rancidity generally occurs in Fat.
20. The cytoplasmic membrane of which of the following organisms contains sterols?
[A] Clostridum
[B] Proteus
[C] Mycoplasma
[D] Bacillius
Show Answer
Correct Answer: C [Mycoplasma]
Notes:
Mycoplasma is a genus of bacteria that do not have a cell wall surrounding the cell membrane.
