CSIR Lifesciences December 2011 part B solved

       1.            21. On the molar scale which of the following interactions in a nonpolar environment provides highest contribution to the biomolecule?

1. van der Waals interaction

2. Hydrogen bonding

3. Salt bridge

4. Hydrophobic interaction

      2.            22. Michaelis and Menten derived their equation using which of the following assumption?

1. Rate limiting step in the reaction is the breakdown of ES complex to product and free enzyme

2. Rate limiting step in the reaction is the formation of ES complex

3. Concentration of the substrate can be ignored

4. Non-enzymatic degradation of the substrate is the major step

      3.            23. In which form of DNA, the number of base pairs per helical turn is 10.5?

1. A

2. B

3. X

4. Z

      4.            24. In contrast with plant cells, the most distinctive feature of  cell division in animal cells is

1. control of cell cycle transitions by protein kinases

2. enzymes responsible for DNA replication

3. ubiquitin-dependent pathway for protein degradation

4. pattern of chromosome movement

      5.            25. Most common type of phospholipids in the cell membrane of nerve cells is

1. phosphatidylcholine

2. phosphatidylinositol

3. phosphatidylserine

4. sphingomyelin

      6.            26. Reverse transcriptase has both ribonuclease and polymerase activities. Ribonuclease activity is required for

1. the synthesis of new RNA strand

2. the degradation of RNA strand

3. the synthesis of new DNA strand

4. the degradation of DNA strand

      7.            27. The membrane lipid molecules assemble spontaneously into bilayers when placed in water and form a closed spherical structure known as

1. lysosome

2. peroxisome

3. liposome

4. endosome

     8.            28. In gene regulation. Open Reading Frame (ORF) implies

1. intervening nucleotide sequence in between two genes

2. a series of triplet codons not interrupted by a stop codon

3. a series of triplet codons that begins with a start codon and ends with a stop codon

4. the exonic sequence of a gene that corresponds to the 5 'UTR of the mRNA and thus does not code for the protein

      9.            29. Amino acid selenocysteine (Sec) is incorporated into polypeptide chain during translation by

1. charging of Sec into tRNAser followed by incorporation through serine codon

2. charging of serine into tRNAser followed by modification of serine into selenocysteine and then incorporation through serine codon

3. charging of Sec into tRNAser and then incorporation through selenocysteine codon

4. charging of serine into tRNAser, modification of serine into selenocysteine and then incorporation through a specially placed stop codon

  10.            30. a-amanitin inhibits

1.  only RNA polymerase I

2.  only RNA polymerase II

3.  only RNA polymerase III

4.  all RNA polymerases

   11.            31. While replicating DNA, the rate of misincorporation by DNA polymerase is 1 in 105 nucleotides. However, the actual error rate in the replicated DNA is 1 in 109 nucleotides incorporated.

This is achieved mainly due to

1. Spontaneous excision of misincorporated nucleotides

2. 3'-5' proof reading activity of DNA polymerase

3. Termination of DNA polymerase at misincorporated sites

4. 5'-3' proofreading activity

  12.            32. Toxic shock is caused by

1. toxins produced by some bacteria

2. excessive stimulation of a large proportion of T cells by bacterial superantigens

3. abnormal cytokine production by B cells

4. excessive production of immunoglobulins

  13.            33. Ethylene binding to its receptor, does NOT lead to

1. dimerization of the receptor

2. phosphorylation of the receptor

3. activation of CTR Raf kinase

4. endocytosis of ethylene-receptor complex

  14.            34. Graft rejection does not involve

1. Erythrocytes

2. T cells

3. macrophages

4. polymorphonuclear leukocytes

   15.            The blastopore region of amphibian embryo that secretes BMP inhibitors and dorsalizes the surrounding tissue is known as

1. Brachet's cleft

2. Nieuwkoop center

3. Spemann's organizer

4. Hensen's node

  16.            During development of embryos in plants, PIN proteins are involved in

1. establishment of auxin gradients

2. regulation of gene expression

3. induction of programmed cell death

4. induction of cell division

   17.            Which of the following maternal effect gene products regulate production of anterior structures in Drosophila embryo?

1. Bicoid and Nanos

2. Bicoid and Hunchback

3. Bicoid and Caudal

4. Nanos and Caudal

  18.             Which of the floral whorls is affected in agamous (ag) mutants?

I. Sepals and petals

2. Petals and stamens

3. Stamens and carpels

4. Sepals and carpels

  19.             Which of the following set of cell organelles are involved in the biosynthesis of jasmonic acid through octadecanoid signalling pathway?

1. Chloroplast and peroxisomes

2. Chloroplast and mitochondria

3. -Mitochondria and peroxisomes

4. Golgi bodies and mitochondria

 20.            Which of the following is NOT a prosthetic group of nitrate reductase

1. FAD

2. Heme

3. Mo

4. Pterin

  21.            Chloroplast distribution in a photosynthesizing cell is governed by blue light sensing phototropin 2 (PHOTO2). When the cells are irradiated with high intensity blue light, the chloplasts

1. move to the side walls

2. aggregate in the middle of the cell

3. are sparsely distributed

4 aggregate in small clusters

 22.             Which of the following acts as a branch point for the biosynthesis of sesquiterpenes and triterpenes?

1. Farnesyl pyrophosphate

2. Geranyl pyrophosphate

3. Isopentyl pyrophosphate

4. Hydroxymcthylglutaryl-CoA

 23.            43. Which of the following waves is likely to be absent in a non11al frog ECG?

1. P

2. Q

3. T

4. R

 24.            44. The atmosphere in a sealed space craft contains

1. pure oxvgen

2. a mix of oxygen and nitrogen

3. a mix of oxygen and carbon dioxide

4. pressurized atmospheric air available normally on earth

  25.            45. in a normal human eye, for sharp image formation on the retina maximum dioptric power is provided by the

1. retina

2. cornea

3. anterior surface of the lens

4. posterior surface of the lens

 26.            46. In this flow diagram name the chemicals A, B, C and D in proper sequence.

1. Renin, Angiotensin II, Angiotensin I, Angiotensinogen

2. Angiotensin I, Angiotensinogen, Angiotensin II, Renin

3. Renin, Angiotensin I, Angiotensin II, Angiotensinogen

4. Renin, Angiotensinogen, Angiotensin I. Angiotensin II

  27.            47. A plant of the genotype AaBb is selfed. The two genes are linked and are 50 map units apart. What proportion of the progeny will have the genotype aabb?

1. 1/2

2. 1/4

3. 1/8

4. 1/16

 28.            48. The base analog 2-aminopurine pairs with thymine, and can occasionally pair with cytosine. The type of mutation induced by 2-aminopurine is

1. transversion

2. transition

3. deletion

4. nonsense

 29.            49. What kind of aneuploid gametes will be generated if meiotic non-disjunction occurs at first division? (‘n' represents the haploid number of chromosomes)

1. only n + 1 and n

2. only n -1 and n

3. both n + 1 and n -1

4. either n + 1 or n – 1

 30.            50. A single-strand nick In the parental DNA helix just ahead of  a replication fork causes the replication fork to break. Recovery from this calamity requires

1. DNA ligase

2. DNA primase

3. site-specific recombination

4. homologous recombination

  31.            51. In transverse sections of a young stem, if vascular canals and carinal canals are present, then the plant belongs to

1. Lycopodiales

2. Isoetales

3. Selaginellales

4. Equisetales

 32.            52. Horse shoe crabs belong to the group

1. Onychophora

2. Chelicerata

3. Uniramia

4. Crustacea

 33.            53. Which of the following groups of species are typical of grassland habitats in India

1. Black buck, wolf, great Indian bustard, lesser florican

2. Spotted deer, dhole, peacock, finch-lark

3. Sambar, tiger, paradise fly catcher

4. Otter, cormorant, darter, pelican

 34.            54. Batrachochytrium dendrobatidis, a fungus, has been

implicated in the decline of populations of

1. fish

2. frogs

3. pelicans

4. bats

  35.            55. The Hutchinsonian concept of ecological niche is based on

1. microhabitat occupied

2. multidimensional hypervolume

3. role played in the ecosystem

4. a combination of role played and microhabitat occupied

 36.            56. Which of the following is NOT a physiological characteristic

of early successional plants?

1. High respiration rate

2. Inhibition by far-red light

3. High transpiration rate

4. Low photosynthetic rate

  37.            57. Aquatic primary production was measured using Light-and-Dark Bottle technique. If the initial oxygen concentration was I and the final oxygen concentration in the light bottle was L and that in the dark bottle D, the gross productivity (in terms of oxygen released) is given as

1. L -I

2. I -D

3. I -L

4. L -D

 38.             Wetlands are conserved internationally through an effort called as

1. Basel Convention

2. Rio Convention

3. Montreal Convention

4. Ramsar Convention

 39.            The first living beings on earth were anaerobic because

1 there was no oxygen in air

2. oxygen damages proteins

3. oxygen interferes with the action of ribozymes

4. they evolved in deep sea

 40.            Which of the following processes interferes in sequence-based phylogeny?

1. Horizontal gene transfer

2. Adaptive mutations

3. DNA repair

4. Reverse transcription

  41.            61. The peacock's tail is an example of

1. natural selection

2. diversifying selection

3. sexual selection

4. group selection

 42.            62. A specialist species has a

1. wider niche and high efficiency of niche utilization

2. narrower niche and high efficiency of niche utilization

3. wider niche and low efficiency of niche utilization

4. narrower niche and low efficiency of niche utilization

 43.            63. To keep them in a totipotent state, embryonic stem cells need to be maintained in a medium supplemented with

1. growth hormone

2. leukemia inhibiting factor

3. nestin

4: insulin

 44.            64. Which of the following features is NOT shown by glyphosate, a broad spectrum herbicide?

1. Little residual soil activity

2. Ready translocation in phloem

3. Inhibition of a chloroplast enzyme catalyzing the synthesis of

aromatic amino acids

4. Inhibition of early steps in the biosynthesis of branched chain

amino acids

  45.            65. The rattans and canes that we use in furniture belong to

1. bamboos

2. palms

3. arborescent lilies

4. legumes

 46.            66. The presence of Salmonella in tap water is indicative of contamination with

1. industrial effluents

2: human excreta

3. agriculture waste

4. kitchen waste

  47.            67. Indirect immunofluorescence involves fluorescently labeled

1. immunoglobulin-specific antibodies

2. antigen-specific antibodies

3. hapten-specific antibodies

4. carrier-specific antibodies

 48.            68. A sample counted for one minute shows a count rate of 752 cpm. For how many minutes should it be counted to have 1 % probable error?

1. 13

2. 5

3. 2

4. 75

 49.            69. Measurement and mapping with spatial resolution the membrane potential of a cell, which is too small for microelectrode impalement, is done using

1. radioisotope

2. voltage-sensitive dye

3. pH sensitive chemical

4. vital dyes

 50.            70. One of the methods for finding common regulatory motifs present in a set of coregulated genes is

1. Prosite

2. MEME

3. Mat Inspector

4. PSSM