11. The study of Improvement of human race by improving environment is known as ?
[A] Euthenics
[B] Eugenics
[C] Euphenics
[D] Etiology
Show Answer
Correct Answer: A [Euthenics]
Notes:
Euthenics is the branch of biology that studies the improvement of human race by improving environment. Eugenics is the branch of biology that studies the Improvement of human race through laws of heredity. Euphenics is the branch of biology that studies the improvement of human race by drug treatment or genetic engineering. Etiology is the branch of biology that studies the Life cycle of causal organisms of the disease.
12. Which movements of “Touch me not plant” lead to closing of its leaves when touched?
[A] Nyctinastic movements
[B] Seismonastic movements
[C] Chemonastric movements
[D] Photonastic movements
Show Answer
Correct Answer: B [Seismonastic movements]
Notes:
Seismonastic Movement is caused by the mechanical stimuli like shock, touch, fast moving wind, etc. Mimosa pudica is a perennial herb which is also known as the touch me not plant or the sensitive plant, is well-known for closing its leaves (or folding its leaves inwards) when touched.
13. Dehydration in human body is caused due to the deficiency of which of the following?
[A] Water
[B] Hormones
[C] Vitamin
[D] Salt
Show Answer
Correct Answer: A [Water]
Notes:
Dehydration is a deficiency of water in thebody. Vomiting, diarrhea, excessive sweating, burns, kidney failure, and use of diuretics maycause dehydration. People feel thirsty, and asdehydration worsens, they may sweat less and excrete less urine.
14. Genetic code is made up by the four-letter alphabet forming the pairs? (UPSC Prelims 1985)
[A] A—C, C—A, T—G, G—T
[B] A—G, G—A, C—A, T—C
[C] T—G, G—T, A—C, C—A
[D] A—T, T—A, C—G, G—C
Show Answer
Correct Answer: D [A—T, T—A, C—G, G—C]
Notes:
The four letters designating these bases (A, G, C, and T) are the alphabet of the genetic code. Each rung of the DNA molecule is contains a combination of two of these letters, one jutting out from each side. In this genetic code, A always combines with T, and C with G to make what is called a base pair.
15. ‘Lathyrism’ is a crippling disease caused by eating which of the following? (UPSC Prelims 1989)
[A] Tinned fish
[B] Chick pea and pulses
[C] Meat
[D] Adulterated oil
Show Answer
Correct Answer: B [Chick pea and pulses]
Notes:
The lathyrism resulting from the ingestion of Lathyrus odoratus seeds (Chick pea and pulses) is often referred to as odoratism or osteolathyrism, which is caused by a different toxin (beta-aminopropionitrile) that affects the linking of collagen, a protein of connective tissues.
16. When compared to the mammals, birds are less sensitive to temporary deprivation of water, because? (UPSC Prelims 1990)
[A] The water requirement per unit weight is less in birds than in mammals.
[B] Absorption of water from the gut is more efficient in birds than in mammals.
[C] Urea excretion in mammals entails a greater loss of water than that in birds.
[D] None of these
Show Answer
Correct Answer: A [The water requirement per unit weight is less in birds than in mammals.]
Notes:
When compared to the mammals, birds are less sensitive to temporary deprivation of water, because the water requirement per unit weight is less in birds than in mammals.
17. Which one of the following is monogamous? (UPSC Prelims 2002)
[A] Wolf
[B] Walrus
[C] Seal
[D] Deer
Show Answer
Correct Answer: A [Wolf]
Notes:
Wolf alpha pairs are usually monogamous with each other, but alpha males have been known to stray with other pack members, especially if they are closely related. Among red foxes, long considered extremely loyal, mate switching has also been shown.
18. How many bones are present in healthy adult human being?
[A] 205
[B] 207
[C] 206
[D] 208
Show Answer
Correct Answer: C [206]
Notes:
An adult human skeleton comprises of 206 bones which is greater than the number of bones present at birth. This is due to the fusing of bones as one grows up. The bone density in the human body reaches maximum at the age of 21.
19. Enzyme neuraminidase is carried by which of the following virus?
[A] Human immunodeficiency virus
[B] Epstein-Barr virus
[C] Influenza virus
[D] Adenovirus
Show Answer
Correct Answer: C [Influenza virus]
Notes:
Viral neuraminidase is a type of neuraminidase found on the surface of the influenza virus that enables the virus to be released from the host cell. Neuraminidases are enzymes that dissociate sialic acid groups from glycoproteins.
20. Which of the following oncogenic virus was first detected?
[A] Rous sarcoma virus
[B] Epstein-Barr virus
[C] Herpes simplex virus type 2
[D] Human T cell leukaemia virus
Show Answer
Correct Answer: A [Rous sarcoma virus]
Notes:
Rous sarcoma virus(RSV) was discovered in 1911 by Peyton Rous.
