Description : Which of the following statements is not correct? (a) An action potential in an axon does not move backward because the segment behind is in a refractory phase. (b) Depolarisation of hair cells ... d) In the knee-jerk reflex, stimulus is the stretching of muscle and response is its contraction.
Last Answer : (c) Rods are very sensitive and contribute to daylight vision.
Description : The sodium/potassium pump is primarily responsible for the: a) resting potential b) action potential c) excretion of salts d) contraction of muscle fibers
Last Answer : ANSWER: A -- RESTING POTENTIAL
Description : Microtubule is involved in the (a) muscle contraction (b) membrane architecture (c) cell division (d) DNA recognition
Last Answer : (c) cell division
Description : The following are true about potassium: a. hypokalaemia decreases the time of cardiac repolarization b. hyperkalaemia decreases cardiac contraction c. hyperkalaemia relaxes vascular smooth muscle d. all
Last Answer : all
Description : Name the ion responsible for unmasking of active sites for myosin for cross-bridge activity during muscle contraction. (a) Calcium (b) Magnesium (c) Sodium (d) Potassium
Last Answer : (a) Calcium
Description : Which one of the following describes the mode of action of tetanospasmin? a. It inhibits muscle contraction. b. It damages and lyses red blood cells. c. It disrupts cell tissues. d. It inhibits muscle relaxation.
Last Answer : d. It inhibits muscle relaxation.
Description : ADH or vasopressin is (a) enzyme that hydrolyses peptides (b) hormone secreted by pituitary that promotes reabsorption of water from glomerular filtrate (c) hormone that promotes glycogenolysis (d) energy rich compound connected with muscle contraction.
Last Answer : (b) hormone secreted by pituitary that promotes reabsorption of water from glomerular filtrate
Description : In the neurone: a. the magnitude of the action potential is dependent on the strength of the stimulus b. impulses can travel in both direction c. depolarization is accompanied by increased ... potassium ions d. during depolarization, the potential of the neurone changes from -70mV to +40mV
Last Answer : during depolarization, the potential of the neurone changes from -70mV to +40mV
Description : The following points about microfilaments are true except (A) They form cytoskeleton with microtubules (B) They provide support and shape (C) They form intracellular conducting channels (D) They are involved in muscle cell contraction
Last Answer : C
Description : The effect of noradrenaline on the heart include: a. tachycardiac b. increased duration of the cardiac action potential c. decreased potassium conductance of the membranes of pacemaker cells d. increased strength of cardiac contraction
Last Answer : increased strength of cardiac contraction
Description : When the potential difference across a membrane of a neuron equals the threshold, what results? a) movement of the membrane b) action potential c) relaxation d) contraction
Last Answer : ANSWER: B -- ACTION POTENTIAL
Description : The sequence of events in muscle contraction a. action potential depolarise the T-tubules b. depolarisation of T-tubules release calcium from sarcoplasmic reticulum c. calcium binds to the troponin-tropomycin complex d. all above
Last Answer : all above
Description : The following are true about an action potential in a nerve fibre: a. it occurs when its membrane potential is hyperpolarized b. it is associated with a transient increase in membrane ... permeability to potassium d. it has an amplitude which varies directly to the strength of stimulus
Last Answer : there is a decreased in membrane permeability to potassium
Description : Which of the following property of prostaglandins has been utilized by chinicians in hospital for (A) Inducing fever (B) Causing inflammation (C) Effecting smooth muscle contraction (D) Disaggregation of spermatozoa
Last Answer : Answer : C
Description : The hormone required for uterine muscle contraction for child birth is (A) Progesterone (B) Estrogen (C) Oxytocin (D) Vasopressin
Description : The four sketches (A, B, C and D) given below, represent four different types of animal tissues. Which one of these is correctly identified in the options given, along with its ... Smooth Heart Heart muscle contraction tissue (d) (A) Columnar Nephron Secretion epithelium and absorption
Last Answer : (a) (B) Glandular Intestine Secretion epithelium
Description : Which of the following is not a function performed by muscle through contraction? a) motion b) maintenance of posture c) hemopoiesis d) heat production
Last Answer : ANSWER: C -- HEMOPOIESIS
Description : One of the important functions of prostacyclins is (A) Inhibition of platelet aggregation (B) Contraction of uterus (C) Decrease of gastric secretion (D) Relieving osthma
Last Answer : Answer : A
Description : In heart cells, which of the following serves as a secondary messenger, speeding up muscle cell contraction in response to adrenaline ?
Last Answer : In heart cells, which of the following serves as a secondary messenger, speeding up muscle cell contraction in ... A. cAMP B. cGMP C. GTP D. ATP
Description : In the mammalian body, this element plays many important roles. Try to identify this element with the fewest number of clues. This element is required to insure the integrity and permeability of ... involved in blood coagulation and is the most important element of bone salt. Name this element.
Last Answer : ANSWER: Calcium
Description : One of the symptoms of low serum potassium concentration includes (A) Muscle weakness (B) Confusion (C) Numbness (D) Tingling of extremities WATER AND ELECTROLYTE BALANCE 283
Description : Potassium content of muscle tissue in mg/100 ml is about (A) 50–100 (B) 100–150 (C) 250–400 (D) 150–200
Description : A striking feature of living cells is a marked difference between the composition of the cytosol and the extracellular milieu. Which of the following statement(s) concerning the mechanisms of maintenance ... d. The selectivity of cell membranes relates only to ions and not organic compounds
Last Answer : Answer: a The survival of the cell requires that cytosolic composition be maintained within narrow limits, despite the constant influx of nutrients and the simultaneous outflow of waste. A ... be altered drastically as a result of regulatory or signaling processes that occur within the cell
Description : How does the sodium-potassium pump present in the cell membrane work ?
Last Answer : What is the importance of this protein for the cell? The sodium-potassium pump is the transport protein that maintains the concentration gradient of these ions between the intra and the ... maintain the cellular metabolism. Cell Membrane Review - Image Diversity: sodium-potassium pump
Description : Insulin increases the permeability of glucose across the plasma membrane of muscle cells by (A) Acting on adenylate cycle (B) By loosening the integrity of the membrane (C) Through Ca2 ... membrane cruting the hexose carries of intracellular organelles and making them fuse with the plasma membrane
Last Answer : Answer : D
Description : The positive inotropic action of digoxin takes several hours to develop because: A. Binding of digoxin to Na+K+ATPase is slow B. After Na+K+ATPase inhibition by digoxin, Ca2+ loading of myocardial ... +ATPase through modification of gene function which takes time D. Both A' and B' are correc
Last Answer : D. Both ‘A’ and ‘B’ are correct
Description : In most nerve and muscle cell, the membrane potentical is a. 60 mv b. 70 mv c. 85 mv d. 100 mv
Last Answer : 85 mv
Description : The enzyme glucose 6-phosphatase is present in (A) Liver (B) Muscle (C) Adipose tissue (D) Brain
Description : Tarui disease is characterized by the deficiency of the enzyme: (A) Liver phosphorylase (B) Muscle phosphorylase (C) Muscle and erythrocyte phosphofructokinase (D) Lysosomal acid maltase
Description : Her’s disease is characterized by deficiency of (A) Muscle phosphorylase (B) Liver phosphorylase (C) Debranching enzyme (D) Glycogen synthase
Last Answer : Answer : B
Description : Mc Ardle’s syndrome is characterized by the absence of (A) Liver phosphorylase (B) Muscle phosphorylase (C) Branching enzyme (D) Debranching enzyme
Description : The enzyme glucose-6-phosphatase which catalyses the conversion of glucose 6-phosphate to glucose is not found in (A) Liver (B) Muscle (C) Intestine (D) Kidney
Description : The enzyme systems for lengthening and shortening for saturating and desaturating of fatty acids occur in (A) Intestine (B) Muscle (C) Kidney (D) Liver
Description : The figure below shows the structure of a mitochondrion with its four parts labelled A, B, C and D. Select the part correctly matched with its function. D B A C (a) D (outer ... possesses single circular DNA molecule and ribosomes (d) A (matrix) - major site for respiratory chain enzyme
Last Answer : (b) B (inner membrane) – forms infoldings called cristae
Description : According to the sliding - filament model of muscle contraction, the molecules that moves to shorten a muscle are :-
Last Answer : According to the sliding - filament model of muscle contraction, the molecules that moves to shorten ... B. Collagen C. Myosin D. Creatine phosphate
Description : During contraction and relaxation of striated muscle fibre the length of A band usually :-
Last Answer : During contraction and relaxation of striated muscle fibre the length of A band usually :- A. ... . Increases C. Decreases D. Decreases too much
Description : During muscle contraction (a)____ energy is converted into (b)____ energy
Last Answer : During muscle contraction (a)____ energy is converted into (b)____ energy
Description : Contraction of a muscle is caused by
Last Answer : Contraction of a muscle is caused by
Description : Muscle contraction is initiated by a signal sent by the _____
Last Answer : Muscle contraction is initiated by a signal sent by the _____
Description : The main source of energy during muscle contraction is____
Last Answer : The main source of energy during muscle contraction is____
Description : Mechanism of muscle contraction is best explained by____
Last Answer : Mechanism of muscle contraction is best explained by____
Description : Assertion : The contraction and relaxation of muscle fiber are controlled by nerve impulses. Reason : The threshold stimulus is the minimum stimulus r
Last Answer : Assertion : The contraction and relaxation of muscle fiber are controlled by nerve impulses. Reason : ... D. If both Assertion and Reason are false.
Description : The following diagram (Figure 20, 35) describes the muscle contraction . Identify A to D
Last Answer : The following diagram (Figure 20, 35) describes the muscle contraction . Identify A to D A. ... Actin filament, C-Silding/Rotation , D-Cross bridge,
Description : ATP provides energy of muscle contraction by allowing for
Last Answer : ATP provides energy of muscle contraction by allowing for A. Cross-bridge attachment of myosin to ... Release of `Ca^(+)` from sarcoplasmic reticulum
Description : Immediate source of energy for muscle contraction is
Last Answer : Immediate source of energy for muscle contraction is A. Glucose B. GTP C. Creatine phosphate D. ATP
Description : Basic unit of muscle contraction is
Last Answer : Basic unit of muscle contraction is A. Actin B. Myosin C. Sarcomere D. Tropomyosin
Description : Chemical ions responsible for muscle contraction are
Last Answer : Chemical ions responsible for muscle contraction are A. `Ca^(++) and K^(+)` B. `Na^(+) and K^(+)` C. `Na^(+ ... ^(++)` D. `Ca^(++) and Mg^(++) ions `
Description : The contraction of muscle of shortest duration is seen in
Last Answer : The contraction of muscle of shortest duration is seen in A. Jaws B. Eyelids C. Heart D. Intestine
Description : The lactic acid generated during muscle contraction us flnally converted to glycogen in
Last Answer : The lactic acid generated during muscle contraction us flnally converted to glycogen in A. Muscle B. Kidney C. Liver D. Pancreas
Description : According to sliding filament theory of muscle contraction, the filament that move to shorten a muscle are
Last Answer : According to sliding filament theory of muscle contraction, the filament that move to shorten a muscle ... B. Actin C. Collagen D. Creatine phosphate