11. Which of the following features of the human immunodeficiency virus (HIV) makes it a living entity? (UPSC Prelims 1990)
[A] Excrete in human serum
[B] Disturb host cell respiration
[C] Undergo auto-reproduction
[D] Move from one cell to another
Show Answer
Correct Answer: C [Undergo auto-reproduction]
Notes:
The human immunodeficiency virus is a type of virus called a retrovirus. Like all viruses, human immunodeficiency virus reproduces using the genetic machinery of the cell it infects. With the help of an enzyme called integrase (also produced by HIV), the viral DNA becomes integrated with the cell’s DNA.
12. Which of the following is done by an Antigen? (UPSC Prelims 1997)
[A] Lowers body temperature
[B] destroys harmful bacteria
[C] triggers the immune system
[D] is used as an antidote to poison
Show Answer
Correct Answer: C [triggers the immune system]
Notes:
An antigen is any substance that causes your immune system to produce antibodies against it. An antigen may be a substance from the environment, such as chemicals, bacteria, viruses, or pollen. An antigen may also form inside the body.
13. Which vitamin is also called as niacin?
[A] Vitamin C
[B] Vitamin B3
[C] Vitamin B12
[D] Vitamin B9
Show Answer
Correct Answer: B [Vitamin B3]
Notes:
Vitamin B3 is also called as niacin/Nicotinic acid with chemical formula C6H5NO2. Niacin is water soluble vitamin.
14. Which blood group is referred to as universal recipient?
[A] AB +ve
[B] AB -ve
[C] O +ve
[D] O -ve
Show Answer
Correct Answer: A [AB +ve]
Notes:
Persons with AB +ve blood group are called as universal recipients as they can get blood from persons with any of the blood groups. AB -ve cannot be regarded as universal donor as it cannot accept blood from persons with Rh factor.
15. Which among the following is correct about Karyology?
[A] Study of breasts
[B] Study of pigments
[C] Study of cancer
[D] Study of nucleus
Show Answer
Correct Answer: D [Study of nucleus]
Notes:
The study of the cell nucleus with reference to the number and size of chromosomes is called Karyology.
16. Which of the following is the largest group of the plant kingdom?
[A] Thallophyta
[B] Bryophyta
[C] Pteridophyta
[D] Euglena
Show Answer
Correct Answer: A [Thallophyta]
Notes:
The plant kingdom consists of 390,000 species known till date. The plant kingdom is divided into five major groups: Thallophyta, Bryophyta, Pteridophyta, Gymnosperms and Angiosperms.
17. Who among the following discovered the plasma membrane?
[A] Robert Hooke
[B] Albert von Kolliker
[C] George E. Palade
[D] Rudolf von Kölliker
Show Answer
Correct Answer: A [Robert Hooke]
Notes:
The plasma membrane is mainly composed of fatty-acid-based lipids and proteins. Robert Hooke discovered the plasma membrane.
18. Which of the following is not a characteristic of Bryophyta?
[A] Motile sperms
[B] Presence of archegonium
[C] Presence of archegonium
[D] Photosynthetically independent sporophyte
Show Answer
Correct Answer: D [Photosynthetically independent sporophyte]
Notes:
Motile sperms, the Presence of archegonium, and the Presence of archegonium are characteristics of Bryophyta.
19. Equisetum is an example of__?
[A] bryophytes
[B] pteridophytes
[C] Gymnosperms
[D] None of these
Show Answer
Correct Answer: B [pteridophytes]
Notes:
Equisetum is an example of pteridophytes. Hornworts, liverworts, and mosses are all examples of bryophytes. Cycas, pinus, Thuja, Cedrus, Abies, Larix are some of the examples of gymnosperms.
20. An anaerobic process in which energy can be released from glucose even when oxygen is not available is called__.
[A] Putrefaction
[B] Fermentation
[C] Glycolysis
[D] None of these
Show Answer
Correct Answer: B [Fermentation]
Notes:
An anaerobic process in which energy can be released from glucose even when oxygen is not available is called Fermentation.
