11. Which of the following cells is present in epidermis that surrounds stomatal pore in plants?
[A] Epithelial cells
[B] Guard cells
[C] Subsidiary cells
[D] Accessory cells
Show Answer
Correct Answer: B [ Guard cells ]
Notes:
Guard cells are cells surrounding each stoma. They help to regulate the rate of transpiration by opening and closing the stomata. Guard cells are specialized cells in the epidermis of leaves, stems and other organs that are used to control gas exchange. They are produced in pairs with a gap between them that forms a stomatal pore.
12. Which of the following diseases is caused by virus?
[A] Common cold
[B] Syphilis
[C] Tuberculosis
[D] Cholera
Show Answer
Correct Answer: A [Common cold]
Notes:
A viral disease (or viral infection or infectious disease), occurs when an organism’s body is invaded by pathogenic virus, and infectious virus particles (virions) attach to and enter susceptible cells.
13. Which of the following is the reason behind when one enters a dark room; he is not able to see anything but after some time his vision improves? (UPSC Prelims 1983)
[A] The retina of the eye comes forward
[B] The retina of the eye moves backward
[C] The pupil of the eye contracts
[D] The pupil of the eye dilates
Show Answer
Correct Answer: D [The pupil of the eye dilates]
Notes:
Our eyes cannot see everything clearly when we enter a dark room from a bright light. This is due to the reason that in dark room the pupil is large so when we come out in bright light, a large amount of light enters our eyes and we feel glare.
14. Which of the following is not the Class of Biomolecules?
[A] Carbohydrate
[B] Proteins
[C] Catalyst
[D] Nucleic acids and Lipids
Show Answer
Correct Answer: C [Catalyst]
Notes:
Biomolecules are organic molecules, which are involved in the metabolic process of the living organism. The four important classes of biomolecules are carbohydrates, Proteins, Nucleic acids and Lipids.
15. Which virus belongs to the family Caliciviridae?
[A] Hepatitis B virus
[B] Hepatitis D virus
[C] Hepatitis E virus
[D] All of these
Show Answer
Correct Answer: C [Hepatitis E virus]
Notes:
The Caliciviridae family contains five genera are Norovirus, Sapovirus, Lagovirus, Vesivirus, and Nebovirus.
16. Which virus is most susceptible to chloroform?
[A] Herpes
[B] Influenza
[C] Measles
[D] All of these
Show Answer
Correct Answer: D [All of these]
Notes:
Herpes, Influenza and Measles viruses are most susceptible to chloroform.
17. 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.
18. Iodine is obtained from which of the following members?
[A] Green algae
[B] Brown algae
[C] Red algae
[D] Blue green algae
Show Answer
Correct Answer: B [Brown algae]
Notes:
Kelp such as Fucus and Laminaria are rich sources of iodine. They are members of the Phaeophyceae brown algae.
19. Bryophytes are dependent on water because__?
[A] Archegonium has to remain filled with water for fertilization
[B] Water is essential for fertilization for their homosporous nature
[C] Water is essential for their vegetative propagation
[D] The sperms can easily reach up to egg in the archegonium
Show Answer
Correct Answer: D [The sperms can easily reach up to egg in the archegonium]
Notes:
Bryophytes are dependent on water because the sperms can easily reach up to eggs in the archegonium.
20. Lateral conduction in gymnosperms leaf is done by which of the following?
[A] Veins
[B] Xylem parenchyma
[C] Transfusion tissue
[D] Medullary rays
Show Answer
Correct Answer: C [Transfusion tissue]
Notes:
Lateral conduction in gymnosperms leaf is done by transfusion tissue. In the case of gymnosperms, a single vascular bundle is present in the central vein region of the leaf.
