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Test: Questions for GATE aspirants

Category: Biology

Description: Students preparing for entrance examinations like CSIR, UGC NET, GATE and other entrance examinations for various PG courses will find these questions very helpful.

Keywords: Gate, CSIR, PG, NET, Biology, Lifesciences, entrance examinations

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Which of the following cannot be formed from acetyl CoA in a single step?

acetyl-CoA + oxaloacetate + H2O ------------------------→ citrate + CoA-SH Oxaloacetate is the first substrate to bind to the enzyme. This induces the enzyme to change its conformation, and creates a binding site for the acetyl-CoA. aceto acetyl CoA Malonyl CoA citrate pyruvate

Which of the following inhibitor uncouples electron transport and oxidative phosphorylation?

Azide Dinitrophenol Oligomycin Rotenone

The identification of a compound on the basis of absorption of a particular wavelength of light is done through

A spectrophotometer is employed to measure the amount of light that a sample absorbs. Autoradiography X-ray crystallography Spectrophotometry Chromatography

Milk casein is a

Casein is the name for a family of related phosphoprotein proteins (αS1, αS2, β, κ). These proteins are commonly found in mammalian milk, making up 80% of the proteins in cow milk and between 60% and 65% of the proteins in human milk. Nucleoprotein Phosphoprotein Chromoprotein Glycoprotein

Fibrinogen is converted to fibrin by

thrombin prothrombin plasmin heparin

Km is equal to

The Michaelis constant Km is the substrate concentration at which the reaction rate is half of Vmax. [Vm/V= 1] [s] when V = Vm [s] when V= 0 [s] when V = I/2 Vm

Autonomous extrachromosomal circular DNA molecules are known as

plasmids phages cistrons introns

Lymphocytes that activate B cells and T cells are

T helper cell (TH cells) assist other white blood cells in immunologic processes, including maturation of B cells into plasma cells and memory B cells, and activation of cytotoxic T cells and macrophages, among other functions. Activator B cells Macrophages Helper T cells Cytotoxic T cells

The regions of an antibody that determine its general role, or effector function are its

Effector functions are determined by the constant regions of the heavy chains (Fc). The effector functions of immunoglobulins are mediated by this part of the molecule. Normally the ability of an antibody to carry out an effector function requires the prior binding of an antigen. variable (v) regions constant(c) regions mutated (m) regions bifurcated (b) regions

Which of the following is a hypoglycemic hormone?

adrenaline insulin cortisol glucagon

The region on t-RNA which recognizes the codon on m-RNA is the

anticodon amino acid acceptor arm lump D-arm

An amino acid which is not an intermediate in Krebs’ urea cycle is

arginine ornithine citrulline alanine

The chloride shift involves

Chloride shift is the simultaneous exchange of chloride (Cl−) and bicarbonate (HCO3−) between plasma and the erythrocytes occurring whenever HCO3− is generated or decomposed within the erythrocytes. H+ leaving RBC for each CO2 that enters HCO3 - Ieaying RBC in exchange for Cl- K+ accompanying each HCO3 - ion None

Proto oncogenes are

A proto-oncogene is a normal gene that can become an oncogene due to mutations or increased expression. Present exclusively in viruses Present in fully developed cancer cells The genes present in normal cells similar to viral oncogenes Present in murine sarcoma virus

Non-cyclic photophosphorylation produces all of the following except

ATP NADPH Oxygen Nitrogen

The minimum number of nucleotide—residues required on an m-RNA to code for a polypeptide of 90 amino acid residues is

Three nucleotides on mRNA code for an amino acid. Here we have 90 AA that is 90x3 = 270 bases. 30 90 180 270

Cholic acid is

a bile acid a bile pigment a precursor of cholesterol a vitamin

Actinomycin D is an inhibitor of

Actinomycin D is effective as an inhibitor of transcription. It does this by binding DNA at the transcription initiation complex and preventing elongation by RNA polymerase. Transduction Transcription Translation All the above

Complete aerobic oxidation of one molecule of acetyl coenzyme A produces

2 ATP 8 ATP 12 ATP 15 ATP

Which of the following is classified as a high-energy compound?

glucose-6-phosphate glyceraldehyde-3-phosphate 2-phospho glycerate 1, 3- bis-phospho glycerate