1. A fixed smear of a bacteria culture is subjected to the following solutions in the order listed below and appeared red,
(a) Carbolfuchsin (heated)
(b) Acid-alcohol
(c) Methylene blue
Bacteria stained by this method can be identified as [December 2011]

2. In contrast with plant cells, the most distinctive feature of cell division in animal cells is [December 2011]

3. Transport of water across aquaporins is regulated by the presence of which of the following sequence of three highly conserved amino acids? [June 2011]

4. Eukaryotic genomes are organized into chromosomes and can be visualized at mitosis by staining with specific dyes. Heat denaturation followed by staining with Giemsa produced alternate dark and light bands. The dark bands obtained by this process are mainly [June 2011]

5.77. ATP-driven pumps hydrolyze ATP to ADP and phosphate and use the energy released to pump ions or solutes across a membrane. There are many classes of these pumps and representatives of each are found in all prokaryotic and eukaryotic cells. Which of the following statements about these pumps is NOT correct? [December 2012]

6. An organism that has peroxidase and superoxide dismutase but lacks catalase is most likely an [December 2012]

7. Assuming that the histone octamer forms a cylinder 9 nm in diameter and 5 nm in height and that the human genome forms 32 million nucleosomes, what fraction (approximately)of the volume of nucleus (6 μm diameter) is occupied histone octamers? [June 2012]

8. Cystic fibrosis (CF) trans membrane conductance regulator (CFTR) protein is known to be a cAMP- dependent Cl- channel.CF patients (with mutant CFTR proteins) show reduced Clpermeability and as a result exhibit elevated Cllevel in sweat. To prove this, CFTR proteins (both wild type and mutant) are inserted in a model membrane (liposome) and Cl- transport is followed with radioactive Cl-.it is known that topology of CFTR in membrane is important for its function. Despite no proteolytic degradation of denaturation of CFTR proteins, wild type CFTR failed to transport Cl- in liposome.

9. When cells enter mitosis, their existing array of cytoplasmic microtubules has to be rapidly broken down and replaced with the mitotic spindle, which pulls the chromosomes into the daughter cells. The enzyme Katanin is activated during the onset of mitosis and chops microtubules into short pieces. The possible fate of the microtubule fragments created by Katanin will be [December 2013]

10. Out of the list given below, which is the correct order of increasing lipid bilayer permeability? [December 2013]

11. rapidly growing bacterial species such as E. coli exhibits a typical phase of growth cycle in liquid nutrient broth (Iag phase - log phase - stationary phase - death phase). If a bacterial culture has starting density of 103 cells/ml has a lag time of 10 minutes and a generation time of 10 minutes, what will the cell density be at (cells/ml) 30 minutes? [June 2013]

12. Phosphorylation of series as well as methylation and acetylation of Lysine in histone tails affect the stability of chromatin structure above the nucleosome level and have important consequences for gene expression. The resulting changes in charge are expected to affect the ability of the tails to interact with DNA because [June 2013]

13. Which of the following statements best describe archaebacteria? [December 2014]

14. Which of the following statements about meiosis is NOT true? [December 2014]

15. Histone acetylase and chromatin remodelling complexes are recruited to specific regions of chromatin by [June 2014]

16. 125I-labelJed diaminofluorene (DAF) is a well-known photoactivable hydrophobic probe of plasma membrane integral protein. To determine the approximate length and number of hydrophobic domain in any integral membrane protein, a controlled experiment (following standard protocol) is carried out. In order to ascertain the aforesaid aspects indicate the correct combination of experimental protocols from the following choices: [June 2014]

17. Glycophorin having one highly hydrophobic domain is able to span a phospholipid bilayer membrane only [December 2015]

18. culture medium contains two carbon sources, one is preferred carbon source (glucose) and the second is a nonpreferred source (lactose). Which one below is correct regarding the nature of growth curve of E. coli cultured in this medium? [December 2015]

19. Sting of a bee causes pain, redness and swelling. Melittin is a major peptide in bee venom. Melittin is a membrane binding peptide that is involved in activating phospholipases in the membrane. The possible target phospholipase that is activated by melittin is [June 2015]

20. When bacteria growing at 20°C are warmed at 370C, they are most likely to synthesize membrane lipids with more [June 2015]

21. In context to lac operon, if two bacterial strains P, and P2 with the genotypes OCI+Z- and O+I-Z+ respectively, were used to produce mero-diploid daughter strain D, which one of the following statements correctly predicts the expression of Z gene (β-galactosidase activity) in all the three strains? (O+, I+ and Z+ denote the wild type allele of the respective genes). [June 2015]

22. Which one of the following combinations must be present in a steroid receptor that is located in the cytoplasm? [June 2015]

23. Both sphingomyelin and phosphoglycerides are phospholipids. Which one of the following statements is NOT correct? [December 2016]

24. When bacteria growing at 20°C are warmed at 370C, they are most likely to synthesize membrane lipids with more [June 2015]

25. Insulin increases facilitated diffusion of glucose in muscle cells by:- [December 2016]

26. Fluorescently tagged protein was used to study protein secretion in yeast. Fluorescence was observed in: (a) the Golgi (b) the secretory vesicles (c) the rough ER. Which of the following describes best the sequence in which these events occur? [December 2017]

27. Cells in S-phase of the cell cycle were fused to cells in the following stages of cell cycle: (a) G1 phase, (b) G2 phase, (c) M phase. These cells were then grown in medium containing tritiated thymidine. Maximal amount of freshly labelled DNA is likely to be obtained in Sphase cells fused with [December 2017]

28. A membrane associated protein is composed of seven "alphahelices", with each helix containing 19 hydrophobic residues. While treating the membrane with all kinds of proteases, a major portion of this protein remains intact. Treatment with high salt (till 1.5M NaCl) and buffer with pH 5.0 failed to dissociate this protein from the membrane. Predict the most appropriate nature and orientation of this protein in the membrane. [June 2017]

29. Which one of the following proteins is most likely to be found in the intermembrane space of mitochondria? A protein containing [December 2018]

30. Irrespective of the chromosomal configuration, a single X-chromosome remains active in all diploid human somatic cell lines, Which one of the following mechanisms best accounts for the above phenomenon? [June 2019]

No comments

Powered by Blogger.