Thursday, April 29, 2010

CET (Karnataka) – 2010 - BIOLOGY - Answer Key

1. Due to non-disjunction of chromosomes during spermatogenesis, sperms carry both sex chromosomes (22A + XY) and some sperms do not carry any sex chromosome (22A + 0). If these sperms fertilise normal eggs (22A + X), what types of genetic disorders appear among the offspring ?
Ans: (1) Turner’s syndrome and Klinefelter’s syndrome

2. When a fresh water protozoan is placed in marine water, …………….
Ans: (3) The contractile vacuoles disappear

3. Which one of the following pairs is an example for lateral meristem ?
Ans: (4) Phellogen and fascicular cambium

4. In peritoneal dialysis, ……………
Ans: (2) The blood is not removed from the body and a natural filter is used

5. The following is a scheme showing the electron transport system. Identify the electron carrier molecules indicated as A and B. Choose the correct option.
Ans: (1) A = Coenzyme Q, B = Cytochrome C
Note: The quality of the diagram (scanned) is very bad


6. The sugar present in milk is …………
Ans: (3) Glucose
(4) Lactose

Note: Low concentrations of free glucose (about 0.1 mM) and free galactose (about 0.2 mM) are found in cow milk and milk of other species. Other carbohydrates found free in milk include amino sugars, sugar phosphates, neutral and acid oligosaccharides, and nucleotide sugars. Some of the complex oligosaccharides are thought to be important in helping establish the microflora of the neonate intestine (such as the bifidis factor identified in human milk; see Human Lactation Lesson). Some milk proteins are glycosylated and some milk lipids contain carbohydrate moieties. (Milk Composition and Resource Library – Internet)
The answer would have been lactose if the question were to be “ The chief / principal sugar present in milk …….”.

7. According to Steward’s starch hydrolysis theory, which one of the following is the principal reason for the opening of stomata during daytime ?
Ans: (4) Photosynthetic utilization of CO2 in guard cells

8. Which one of the following processes results in the formation of a clone of bacteria ?
Ans: (1) Binary fission

9. Match the types of immunity listed in Column - I with the examples listed in Column - II. Choose the answer that gives the correct combination of alphabets of the two columns.
Column I Column II
Types of immunity Example

A. Natural active p. Immunity developed by heredity
B. Artificial passive q. From mother to foetus through placenta
C. Artificial active r. Injection of antiserum to travelers
D. Natural passive s. Fighting infections naturally
t. Induced by vaccination
Ans: (4) A = s, B = r, C = t, D = q

10. How do you differentiate a butterfly from a moth ?
Ans: (1) Moth has feathery antennae but butterfly has club-shaped antennae

11. Which one of the following statements is NOT correct ?
Ans: (3) UAA codon codes for Lysine

12. In the absence of acrosome, the sperm ………….
Ans: (1) Can not penetrate the egg

13. The diagram of the ultrasturcture of a plant cell is given below. Identify the functions of the organelles labeled A, B, C, D and E in the diagram.
Ans: (2) A = Principal director of macromolecular traffic, B = Site of oxidative phosphorylation, C = Intracellular transport, D = Site of photophosphorylation, E = Storage of cell sap

14. Which one of the following species of earthworm is NOT recommended for vermicomposting ?
Ans: (4) Pheretima posthuma

15. The main aim of the human genome project is ……………
Ans: (2) To identify and sequence all the genes present in human DNA

16. The species, though insignificant in number, determine the existence of many other species in a given ecosystem. Such species is known as ………….
Ans: (4) Keystone species

17. Compare the statements A and B.
Statement A: Sclerenchyma cells do not have plasmodesmata.
Statement B: The cell walls of some permanent tissues are heavily lignified.
Select the correct description;
Ans: (3) Both the statements A and B are correct

18. Which one of the following is NOT a reason for very high load of bilirubin in a newborn ?
Ans: (3) Mother’s milk contains a high amount of bilirubin

19. Which one of the following diseases is caused by Nosema bombycis in mulberry silkworm ?
Ans: (2) Pebrine

20. The following is the scheme showing the path of reflex arc. Identify the different labellings A, B, C, D, E and F in the reflex arc.
Ans: (2) A = Stimulus, B = Receptor, C = Sensory nerve, D = Motor nerve, E = Effector, F = Response

21. Identify the pair that exhibits “circinate vernation”.
Ans: (3) Nephrolepis and Cycas

22. Pyruvate dehydrogenase complex needed for the conversion of Pyruvic acid to Acetyl Co-A is located in …………….
Ans: (1) Matrix of mitochondria

23. The presence of corollary corona, sagittate anthers and dumb-bell shaped stigma are the characteristic features of …………….
Ans: (3) Catheranthus roseus

24. Every time, when the dosage of a drug has to be increased to achieve the same ‘kick’ that initially occurred in response to a smaller dose, this condition is known as …………..
Ans: (2) Tolerance

25. DNA gyrase, the enzyme that participates in the process of DNA replication, is a type …………….
Ans: (1) DNA topoisomerase

26. Mendel found that the reciprocal crosses yielded identical results. From that, he concluded that ………….
Ans: (4) Sex has no influence on the dominance of traits

27. Compare the statements A and B.
Statement A: Synthesis of DNA takes place in the S - phase of interphase.
Statement B: Every chromosome, during metaphase, has two chromatids.
Select the correct description;
Ans: (3) Both the statements A and B are correct and A is the reason for B

28. Match the animals listed in Column - I with their nature of blood listed in Column – II. Choose the answer which gives the correct combination of alphabets of the two columns.
Column I Column II
A. Man p. Plasma and cells are colourless
B. Earthworm q. Plasma is colourless and nucleated RBC
C. Cockroach r. Plasma is colourless and enucleated RBC
D. Frog s. Plasma is red and nucleated, colourless RBC
t. Plasma RBC have haemoglobin
Ans: None of the option is correct
Note:
Plasma is a straw yellow coloured component of the blood. It is not colourless. Moreover, blood cells in invertebrates like earthworm and cockroach are not called RBCs as they do not contain the respiratory pigment. They are called corpuscles or haemocytes.

29. During lactic acid fermentation, ……………
Ans: (2) Neither O2 is used nor CO2 is liberated

30. Which one of the following is NOT the function of insulin ?
Ans: (3) Initiates the conversion glycogen to glucose

31. Which one of the following is a unicellular, non-motile desmid ?
Ans: (4) Cosmarium

32. Some of the steps involved in the production of humulin are given below. Choose the correct sequence.
(i) Synthesis of gene (DNA) for human insulin artificially
(ii) Culturing recombinant E.coli in bioreactors
(iii) Purification of humulin
(iv) Insertion of human insulin gene into plasmid
(v) Introduction of recombinant plasmid into E.coli
(vi) Extraction of recombinant gene product from E.coli
Ans: (3) i, iv, v, ii, vi, iii

33. Cockroaches can climb smooth and steep surfaces due to the presence of adhesive pads found on the tarsus of their legs. They are called …………..
Ans: (1) Plantulae
(4) Arolium
Note:
Arolium is also a pat of the pretarsus. But it is present between the two claws and is attached to the pretarsus.

34. Gastrula has a pore which is known as ……………
Ans: (1) Blastopore

35. The diagram of Labeo rohita is given below. Identify the parts labelled A, B, C, D, E and G.
Ans: (3) A = Nostril, B = Eye, C = Dorsal fin, D = Caudal fin, E = Anal fin, F = Pelvic fin, G = Pectoral fin

36. Compare the statements A and B.
Statement A: To counteract the increase in turgor pressure in plant cells, the cell wall produces an equal and opposite pressure, i.e., wall pressure.
Statement B: When plant cells undergo endosmosis, they swell but do not burst.
Ans: (1) Both the statements A and B are correct and A is the reason for B

37. When red blood corpuscles containing both A and B antigens are mixed with your blood serum, they agglutinate. Hence, your blood group is ……….. type.
Ans: (2) O

38. Bovine spongiform encephalopathy is a disease caused by prions in a …………..
Ans: (2) Cow

39. Compare the statements A and B.
Statement A: When the urine moves through the descending limb, it becomes hypertonic and as it passes through the ascending limb of Henle’s loop, it becomes hypotonic.
Statement B: The descending limb is permeable to sodium ions, while ascending limb is impermeable to sodium ions.
Ans: (1) Both the statements A and B are wrong
Note: It is not urine which moves in the pct, Henle’s loop and dct, but primary urine or glomerular filtrate.

40. To meet the demands of the society, in vitro production of a large number of plantlets in a short duration is practiced in floriculture and horticulture industry today. This is called …………..
Ans: (4) Micropropagation

41. With reference to enzymes, turnover number means ………………
Ans: (3) The number of substrate molecules that a molecule of an enzyme converts into products per minute

42. The following diagrams A, B, C, D and E show the different types of arrangement of stamens based on their cohesion of their parts in different plants. Assign the stamens to their respective plants. Choose the correct answer.
Ans: (4) A = Hibiscus rosa-sinensis, B = Crotalaria juncea, C = Bombax ceiba, D = Helianthus annus, E = Cucurbita pepo

43. The single horned Rhinoceros is protected at ……………
Ans: (2) Kaziranga National Park

44. According to Boyle’s law, the product of pressure and volume is a constant. Hence,
Ans: (1) if volume of lungs is increased, the pressure decreases proportionately

45. According to Darwin, evolution is …………..
Ans: (2) A slow, gradual and continuous process

46. Succus entericus is secreted by ………….
Ans: None of the option is correct
Note:
Secretion of intestinal glands (both crypts of Lieberkuhn and Brunner’s gland) is called intestinal juice (succus entericus), i.e., succus entericus is the combined secretion of both crypts of Lieberkuhn and Brunner’s gland. The Brunner’s glands open into the crypts of Lirberkuhn. Their secretion contains alkaline mucus which prevents the action of acidic chyme on the mucosal lining of the small intestine.

47. Cell A and cell B are adjacent plant cells. In cell A, Ψs = - 20 bars and Ψp = 8 bars. In cell B, Ψs = -12 bars and Ψp = 2 bars. Then,
Ans: (3) Water moves from cell B to cell A

48. Populations are said to be sympatric when …………….
Ans: (4) Two populations share the same environment but can not interbreed

49. In which of the following situations, is there a risk factor for children of incurring erythroblastosis foetalis ?
Ans: (2) Mother is Rh –ve and father is Rh +ve

50. Compare the statements A and B.
Statement A: RNA produced during transcription in eukaryotic cells can not be straight away used in photosynthesis.
Statement B: RNA splicing phenomenon helps in the removal of exons.
Choose the correct description;
Ans: (1) Both the statements A and B are wrong

51. The diagram of large intestine of man is given below. Identify the parts labeled A, B, C, D, E and F.
Ans: (3) A = Caecum, B = Vermiform appendix, C = Ascending colon, D = Transverse colon, E = Descending colon, F = Sigmoid

52. In genetic fingerprinting, the ‘probe’ refers to ……….
Ans: (1) A radioactively labelled single stranded DNA molecule

53. Which one of the following is NOT a method of soil conservation ?
Ans: (2) Overgrazing

54. In C4 pathway, the CO2 fixation in mesophyll cells is carried out by the enzyme …
Ans: (1) PEP carboxylase

55. Which one of the following is a driving force for the process of passive absorption of water in roots ?
Ans: (4) Transpiration in leaves

56. If the systolic pressure is 120 mm Hg and diastolic pressure is 80 mm Hg, the pulse pressure is
Ans: (3) 120 – 80 = 40 mm Hg

57. Tyloses are found in …………….
Ans: (2) Secondary xylem

58. Which one of the following growth regulators is used to promote synchronized flowering in pineapple ?
Ans: (3) Indolebutyric acid
(4) 2-chloroethylphosphonic acid
Note:
Auxins like NAA, 2,4-D and IBA are also used for synchronised flowering in pineapple and litchi. However, NAA and 2,4-D are preferred over IBA

59. Sporopollenin, a chemical substance is found in ……………..
Ans: (2) Exine of pollen grain

60. Which one of the following statements about the events of non-cyclic photophosphorylation is NOT correct ?
Ans: (1) Only one photosystem participates
(2) ATP and NADPH are not produced


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