Description : $ Endoplasmic reticulum also acts as the cell-skelton. ! Flagellum of a prokaryotic cell is formed of a protein called Tubulin.
Last Answer : $ Endoplasmic reticulum also acts as the cell-skelton. ! Flagellum of a prokaryotic cell is formed of a ... wrong D. If both As and R are wrong.
Description : Which of the following is the contractile protein of a muscle? (a) Tropomyosin (b) Tubulin (c) Myosin (d) All of these
Last Answer : (c) Myosin
Description : The microfilaments composed of (A) Actin protein (B) Gelatin protein (C) Keratin protein (D) Tubulin protein
Last Answer : (A) Actin protein
Description : Microtubules consist of helically stacked molecules of the protein (A) Actin (B) Myosin (C) Keratin (D) Tubulin
Last Answer : (D) Tubulin
Description : Broad spectrum anthelmintics include D A. Benzimidazoles B. Triclabendazole C. Organophosphate D. Both a and b
Last Answer : Both a and b
Description : Binding of acetylcholine to its receptors increases the permeability of cell membrane to (A) Ca++ (B) Na+ (C) K+ (D) Na+ and K+
Last Answer : Answer : D
Description : The mechanism by which neostigmine improves contraction of myasthenic muscle involves: A. Repetitive binding of the acetylcholine molecules to the same receptors at the muscle endplate B. Diffusion of ... Activation of motor end-plate receptors by neostigmine molecules themselves D. All of the above
Last Answer : D. All of the above
Description : Are sunflowers mimicking the way the sun looks?
Last Answer : Besides looking like a sun, they also follow the path of the sun. (Heliotropism.) Mimicking implies it’s changing its appearance to copy the appearance of the sun (like a chameleon). Which sunflowers do not.
Description : What would be the evolutionary advantage given to mockingbirds by mimicking other birds?
Last Answer : Pure speculation here, but since one of the functions of bird song is to lay claim to a territory, maybe it’s the bird equivalent of posting “No Trespassing” signs in several languages. Could be that it deters competition not only from other mockers, but from other rivals for food resources.
Description : I appear to be real but I'm not, I'm perfectly accurate but deceiving, I have no feelings or emotions, but the individual I'm mimicking does. What am I? -Riddles
Last Answer : Your reflection in the mirror.
Description : Prostaglandins are chemical substances thought to a) increase sensitivity of pain receptors. Prostaglandins are believed to increase sensitivity to pain receptors by enhancing the pain-provoking ... opioid medications inhibit the transmission of noxious stimuli by mimicking enkephalin and endorphin.
Last Answer : a) increase sensitivity of pain receptors. Prostaglandins are believed to increase sensitivity to pain receptors by enhancing the pain-provoking effect of bradykinin.
Description : What is rhythm? a. Creating balance in an artwork. b. Adding interest in an artwork. c. Creating movement through an artwork. d. Mimicking sound in an artwork.
Last Answer : c. Creating movement through an artwork.
Description : Which of the following statements regarding cilia is not correct ? (a) Cilia contain an outer ring of nine doublet microtubules surrounding two singlet microtubules. (b) The organised beating of ... (c) Cilia are hair-like cellular appendages. (d) Microtubules of cilia are composed of tubulin
Last Answer : (b) The organised beating of cilia is controlled by fluxes of Ca2+ across the membrane.
Description : The following cytotoxic drug acts by inhibiting depolymerization of tubulin and thus producing abnormal arrays of microtubules: A. Paclitaxel B. Vinblastine C. Etoposide D. Mitoxantrone (p. 774) 60.9 C 60.10 B 60.11 D 60.12 A Ai
Last Answer : A. Paclitaxel
Description : Vinca alkaloids exert antitumor activity by: A. Activating topoisomerase II to cause breaks in DNA strands B. Crosslinking DNA strands C. Inhibiting DNA mediated RNA synthesis D. Inhibiting polymerization of tubulin to form intracellular microtubules
Last Answer : D. Inhibiting polymerization of tubulin to form intracellular microtubules
Description : Which of the following statements is incorrect? (a) Prions consist of abnormally folded proteins. (b) Viroids lack a protein coat. (c) Viruses are obligate parasites. (d) Infective constituent in viruses is the protein coat.
Last Answer : (d) Infective constituent in viruses is the protein coat.
Description : Answer: b, c, d Eosinophils constitute 1% to 3% of the leukocyte population of the bloodstream. They also reside in tissues and they exhibit phagocytic capabilities. They are less ... the cycle of events that result in recruitment and activation of inflammatory cells at sites of inflammation
Last Answer : Cellular injury from oxidants may be manifest by which of the following? a. Cell membrane lipid peroxidation b. DNA strand breaks c. Cytoskeletal disassembly d. ATP depletion
Description : Avermectins act against parasites by C A. Stopping the energy metabolism B. Inhibiting the Cholinesterase C. Changing the chloride ion channel activity D. None of these
Last Answer : Changing the chloride ion channel activity
Description : In the process of transcription in bacterial cells (A) Initiation requires rho protein (B) RNA polymerase incorporates methylated bases in correct sequence (C) Both the sigma unit and core ... RNA polymerase are required for accurate promotor site binding (D) Primase is necessary for initiation
Last Answer : Answer : C
Description : Chloramphenicol inhibits bacterial protein synthesis by: A. Binding to 30S ribosome and inhibiting attachment of aminoacyl tRNA B. Binding to 50S ribosome and preventing peptide bond formation C. Binding to ... chain D. Binding to both 30S and 50S ribosome and inducing misreading of mRNA code
Last Answer : B. Binding to 50S ribosome and preventing peptide bond formation
Description : Numerous antibodies can be prepared, against one antigen, each binds to unique epitopes. How is this antibody diversity generated? A- By rearrangements of the DNA encoding the variable regions of the heavy ... proteins can physically change their shape to bind different epitopes D- Both (a) and (b)
Last Answer : Both (a) and (b)
Description : With regard to the autonomic nervous system: a. the dorsal root ganglia is made up mainly of the cell bodies of the sympathetic nerves b. the preganglionic sympathetic fibres ... the ganglia of both sympathetic and parasympathetic nervous system d. botulin toxin blocks acetylcholine receptors
Last Answer : the dorsal root ganglia is made up mainly of the cell bodies of the sympathetic nerves
Description : Select the prokinetic-antiemetic drug which at relatively higher doses blocks both dopamine D2 as well as 5-HT3 receptors and enhances acetylcholine release from myenteric neurones: A. Cisapride B. Prochlorperazine C. Metoclopramide D. Domperidon
Last Answer : C. Metoclopramide
Description : Acetylcholine has no therapeutic application because: A. None of its actions are beneficial in any condition B. Its effects are transient C. It produces wide spread actions affecting many organs D. Both ‘B’ and ‘C’ are correct
Last Answer : D. Both ‘B’ and ‘C’ are correct
Description : Lactose or its analogues act as positive regulators of lac operon by (A) Attaching to i gene and preventing its expression (B) Increasing the synthesis of catabolite gene activator protein (C) ... holoenzyme (D) Binding to repressor subunits so that the repressor cannot attach to the operator locus
Description : Binding of RNA polymerase holoenzyme to the promoter region of lac operon is facilitated by (A) Catabolite gene activator protein (CAP) (B) cAMP (C) CAP-cAMP complex (D) None of these
Description : The unwound strands of DNA are held apart by (A) Single strand binding protein (B) Double strand binding protein (C) Rep protein (D) DNAA protein
Last Answer : Answer : A
Description : Initiation of protein synthesis begins with binding of (A) 40S ribosomal unit on mRNA (B) 60S ribosomal unit (C) Charging of tRNA with specific amino acid (D) Attachment of aminoacyl tRNA on mRNA
Description : The function of a repressor protein in an operon system is to prevent synthesis by binding to (A) The ribosome (B) A specific region of the operon preventing transcription of structural genes (C) The RNA polymerase (D) A specific region of the mRNA preventing translation to protein
Last Answer : Answer : B
Description : Phosphorylated IRS-1 activates GRB-2 which is (A) G-protein receptor binding protein-2 (B) Growth factor receptor binding protein-2 (C) Growth hormone receptor binding protein-2 (D) Glucocorticoid receptor binding protein-2 226 MCQs IN BIOCHEMISTRY
Description : Binding of thyroxine to its receptors (A) Activates Adenylate cyclase (B) Activates guanylate cyclase (C) Activates a stimulatory G-protein (D) Increases transcription
Description : The only correct statement about hormone receptors is (A) Receptors for protein hormones are present in cytosol (B) Receptors for steroid hormones are membrane bound (C) Hormone-receptor binding is irreversible (D) Receptors can undergo down regulation and up regulatoin
Description : A specific cortisol binding protein, transcortin is a (A) Albumin (B) α1-Globulin (C) α2-Globulin (D) β-Globulin
Description : Calcitriol facilitates calcium absorption by increasing the synthesis of the following in intestinal mucosa: (A) Calcium Binding Protein (B) Alkaline Phosphatase (C) Calcium-dependent ATPase (D) All of these
Description : Retinol and Retinol binding protein are bound with this protein: (A) Albumin (B) Prealbumin (C) α-globulin (D) β-globulin
Description : Retinol and retinol –binding protein (RBP) bound with this protein: (A) Albumin (B) Prealbumin (C) α2-globulin (D) β-globulin
Description : Retinol is transported in blood bound to (A) Aporetinol binding protein (B) α2-Globulin (C) β-Globulin (D) Albumin
Description : Free fatty acids are transported in the blood (A) Combined with albumin (B) Combined with fatty acid binding protein (C) Combined with β -lipoprotein (D) In unbound free salts
Description : Which of the following statement(s) is/are true concerning the antibody response to an invading antigen? a. All antibodies are composed of one type of heavy and one type of light protein chain b. ... stimulus d. Immunoglobulins A, D, and E play an active role in the circulating humoral response
Last Answer : Answer: a Humoral defenses consist of antibody (immunoglobulin; Ig) and complement. All Ig classes (IgM, IgG, IgA, IgE, IgD) and IgG subclasses are composed of one type (M, G, A, E, D ... exist in smaller amounts in the circulation and do not appear to play a major role as host defense components
Description : Most hormone receptors are localized on the cell membrane and transduce hormone binding into altered levels of intracellular messengers. A limited number of intracellular receptors do exist. Which of ... protein serves as an inhibitor protein blocking the DNA-binding domain of the steroid receptor
Last Answer : Answer: a, d Although most hormone and other messenger receptors are extracellular, intracellular receptors have been identified. The hormone messengers involved for these receptors are primarily ... DNA-binding domain of the receptor. Activation involves the dissociation of the inhibitor protein
Description : Which of the following statement(s) is/are true concerning cell membrane receptors? a. The largest family of cell surface receptors are the G-protein-linked receptors b. Activities of the ... through the use adenylate cyclase d. Tyrosine kinase receptors are considered G-protein-linked receptors
Last Answer : Answer: a, c All water-soluble regulatory molecules bind to the cell surface receptor proteins. Binding of the appropriate ligand evokes an intracellular signal which usually regulates ... are adenylate cyclase, which converts ATP to cAMP, and the polyphosphoinositide-specific phospholipase C
Description : The termination of heparin activity by protamine sulfate is due to (a) A chelating action (b) The inhibition of gastrointestinal absorption of heparin (c) The displacement of heparin-plasma protein binding (d) An acid-base interaction (e) The prothrombin-like activity of protamine
Last Answer : Ans: D
Description : Methicillin resistant staphylococci do not respond to ß-lactam antibiotics because (a) They produce a ß-lactamase which destroys methicillin and related drugs (b) They elaborate an amidase which destroys ... low affinity for ß-lactam antibiotics (d) They are less permeable to ß-lactam antibiotics
Last Answer : Ans: C
Description : The retinal pigment epithelium cells: a. esterify and store excess retinol b. transport retinol binding protein from blood to subretinal space c. are secured laterally to each other by tight junction d. all above
Last Answer : all above
Description : Which one of the following statements regarding enzyme inhibition is correct? (a) Competitive inhibition is seen when a substrate competes with an enzyme for binding to an inhibitor protein. (b ... large amount of substrate. (d) Non-competitive inhibitors often bind to the enzyme irreversibly.
Last Answer : (b) Competitive inhibition is seen when the substrate and the inhibitor compete for the active site on the enzyme
Description : Heavy metals, such as____work by _____‗‗ a. Mercury; Disrupting Membranes b. Copper; Producing Toxins c. Iodine; Denaturing Proteins d. Silver; Binding Protein Molecules Together
Last Answer : d. Silver; Binding Protein Molecules Together
Description : Which of the following may be most likely to be missing from a gram-positive bacterium? A.Penicillin binding protein B.Peptidoglycan C.Lipopolysaccharide D.Phospholipid bilayer membrane
Last Answer : C.Lipopolysaccharide
Description : Negative regulation of protein synthesis is accomplished by A- allosteric inhibition B- the binding of RNA polymerase to the promoter C- the binding of a repressor to the DNA D- the binding of a repressor to the RNA polymerase
Last Answer : the binding of a repressor to the DNA