11. Which of the following is the first formed primary xylem elements?
[A] Protoxylem
[B] Xylem parenchyma
[C] Metaxylem
[D] Xylem fibres
Show Answer
Correct Answer: A [Protoxylem]
Notes:
Protoxylem is the first part of the primary xylem that matures and these cells are usually smaller than the metaxylem. Metaxylem is the part of the primary xylem that differentiates after the protoxylem and these cells are usually larger than the protoxylem.
12. RBCs are formed in which of the following in the adults?
[A] black bone marrow
[B] white bone marrow
[C] red bone marrow
[D] blue bone marrow
Show Answer
Correct Answer: C [red bone marrow]
Notes:
There are two types of bone marrow: red marrow (also known as myeloid tissue) and yellow marrow. Red blood cells, platelets and most white blood cells arise in red marrow; some white blood cells develop in yellow marrow.
13. Which one of the following diseases is least infectious? (UPSC Prelims 1991)
[A] Leprosy
[B] Tuberculosis
[C] Conjunctivitis
[D] Hepatitis
Show Answer
Correct Answer: D [Hepatitis]
Notes:
Most noninfectious causes of hepatitis are not contagious. Hepatitis caused by alcohol poisoning, medications, or toxins or poisons are not transmitted from person to person.
14. Consumption of fish is considered to be healthy when compared to flesh of other animals because fish contains which of the following minerals? (UPSC Prelims 1998)
[A] Polyunsaturated fatty acids
[B] saturated fatty acids
[C] essential vitamins
[D] more carbohydrates and proteins
Show Answer
Correct Answer: A [Polyunsaturated fatty acids]
Notes:
Consumption of fish is considered to be healthy when compared to flesh of other animals because fish contains polyunsaturated fatty acids. Polyunsaturated fatty acid is an anti oxidant, which helps in building of tissues.
15. Which vitamin is also called as ascorbic acid?
[A] Vitamin A
[B] Vitamin C
[C] Vitamin D
[D] Vitamin K
Show Answer
Correct Answer: B [Vitamin C]
Notes:
Vitamin C is also called as ascorbic acid. Deficiency in vitamin C leads to scurvy. Chemical formula of vitamin C is C6H8O6.
16. A.I. Oparin is related to which of the following theories in the field of biology?
[A] Chemosynthetic theory
[B] A Theory of Life
[C] Infectious Disease Theory
[D] A Theory of the Origin of Eukaryotic Cells
Show Answer
Correct Answer: A [Chemosynthetic theory]
Notes:
The Chemosynthetic theory of origin of life was proposed by A.I. Oparin. Chemosynthetic theory states that life originated on earth through a series of collections of chemical elements in the water.
17. Which modern concept was pioneered by Rudolf Virchow?
[A] pathological processes
[B] process of fermentation
[C] isotopes as tracers to study chemical and biological processes
[D] None of these
Show Answer
Correct Answer: A [pathological processes]
Notes:
Rudolf Virchow was a German pathologist and politician who pioneered the modern concept of disease processes by his application of cell theory to explain the effects of disease in body organs and tissues.
18. Red algae are known as__?
[A] Chlorophyceae
[B] Rhodophyceae
[C] Phaeophyceae
[D] None of these
Show Answer
Correct Answer: B [Rhodophyceae]
Notes:
Rhodophyceae (red algae) are a class of seaweeds, most of which are reddish in color, with a filamentous or membranous basic shape.
19. How do small molecules pass through the outer membrane of mitochondria?
[A] Carrier protein
[B] Channels
[C] Porins
[D] ATP pump
Show Answer
Correct Answer: C [Porins]
Notes:
The outer membrane is a relatively simple phospholipid bilayer made up of protein structures called porins. This makes it permeable to molecules of about 10 kilodaltons or less.
20. Wounds on the chorioallantoic membrane are produced by__?
[A] Herpes B virus
[B] Vaccinia virus
[C] Herpes simplex virus
[D] all of these
Show Answer
Correct Answer: D [all of these]
Notes:
Wounds on the chorioallantoic membrane are produced by Herpes B virus, Vaccinia virus and Herpes simplex virus.
