11. HIV often changes its shape due to the presence of which of the following enzymes?
[A] Reverse Transcriptase
[B] Enterokinase
[C] Nucleoditase
[D] None of the above
Show Answer
Correct Answer: A [Reverse Transcriptase]
Notes:
A reverse transcriptase is an enzyme used to generate complementary DNA from an RNA template, a process termed reverse transcription. The viral DNA is cut and paste into the host cell DNA. The host cell gets tricked into making lots of proteins for the virus.
12. The young chicks come out of eggs within how many days after being hatched by the hen? (UPSC Prelims 1979).
[A] One week
[B] Two weeks
[C] Three weeks
[D] Four weeks
Show Answer
Correct Answer: C [Three weeks]
Notes:
A hen that is committed to hatching chicks is known as a broody. The state of being broody is controlled by instinct, hormones and lighting conditions. Chicken come out of the eggs within the 21 days after being hatched by the hen. Some breeds take a little less and some a little longer. If the egg has not hatched after 25 days, it should be removed from the broody hen or incubator. Eggs need constant heat during the full incubation period for the embryo to develop into a chick.
13. 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.
14. 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.
15. Which one of the following vitamins is considered to be a hormone? (UPSC Prelims 1994)
[A] A
[B] B
[C] C
[D] D
Show Answer
Correct Answer: D [D]
Notes:
Vitamin D is a hormone the kidneys produce that controls blood calcium concentration and impacts the immune system. It is also known as calcitriol, ergocalciferol, calcidiol and cholecalciferol.
16. Who among the following was awarded the Nobel Prize in Medicine in 1926 for his contribution to cancer research?
[A] Christiaan Eijkman
[B] Johannes Fibiger
[C] Julius Wagner-Jauregg
[D] Charles-Jules-Henri Nicolle
Show Answer
Correct Answer: B [Johannes Fibiger]
Notes:
Johannes Fibiger was awarded the Nobel Prize in Medicine in 1926 for his contribution to cancer research.
17. Which of the following is not a part of the sexual cycle of fungi?
[A] Meiosis
[B] Karyogamy
[C] Mitosis
[D] Plasmogamy
Show Answer
Correct Answer: C [Mitosis]
Notes:
Mitosis is a process where a single cell divides into two identical daughter cells.
18. Which of the following is not true about virus?
[A] Reproduce independently
[B] Contain DNA
[C] Contain RNA
[D] Are extracellular
Show Answer
Correct Answer: A [Reproduce independently]
Notes:
A virus is an infectious agent of small size and simple structure that can multiply only in living cells of animals, plants or bacteria. A virus particle is made up of genetic material housed inside a protein shell, or capsid. The genetic material, or genome, of a virus may be composed of single-stranded or double-stranded DNA or RNA. It can be linear or circular.
19. What does the ‘Perfect stage’ of a fungus indicate?
[A] indicates that it can reproduce asexually
[B] indicates that it is perfectly healthy
[C] indicates that it is able to form perfect sexual spores
[D] All of the above
Show Answer
Correct Answer: C [indicates that it is able to form perfect sexual spores]
Notes:
The ‘Perfect stage’ of a fungus indicates that it is able to form perfect sexual spores.
20. Which is the largest Bryophyta?
[A] Funaria (Moss)
[B] Marchantia
[C] Megaceros
[D] Dowsonia
Show Answer
Correct Answer: D [Dowsonia]
Notes:
Dawsonia is a taxonomy of moss. They are the largest bryophytes. Dawsonia plants are generally known for being tall. It has thicker leaves than the common moss.
