Competitive Exams: Medical Science MCQs (Practice-Test 103 of 135)

  1. Ovulation is caused by

    1. excess of progesterone

    2. mid-cyclic LH surge

    3. mid-cyclic FSH surge

    4. low oestrogen level

  2. Following ovulation, cervical mucus

    1. shows thick cellular pattern

    2. shows fem like pattern on drying

    3. is thin and shows cellular pattern

    4. is thin and alkaline

  3. The source of oestrogen in the postovulatory phase of the menstrual cycle is the

    1. Graafian follicle

    2. Primary follicle

    3. atretic follicles

    4. corpus luteum

  4. Conduction rate is the fastest in

    1. atria

    2. AVN

    3. Purkinje fibres

    4. ventricle

  5. Pacemaker potential

    1. is in the form of a plateau potential

    2. is due to a slow diastolic depolarization

    3. is a graded potential

    4. develops in the right atrial fibres

  6. Cardiac muscle action potential is shown in the given diagram and its phases have been marked. Consider the following statements in this regard:

    1. Phase I is due to closure of Na + channels and CI influx.

    2. Phase II is due to opening of Ca2 + f channels and closure of K + channels.

    3. Phase III is due to closure of Ca2 + channels and prolonged opening of K + channels.

    4. Phase IV is due to opening of Na2 + channels and Cl-efflux.

    Of these statements

    1. 1 and 2 are correct

    2. 2 and 4 are correct

    3. 1 and 3 are correct

    4. 2 and 3 are correct

  7. Consider the following statement:

    1. Experimental hypertension can be produced by stimulating sino-aortic nerve

    2. Sino-aortic nerve normally stimulates vasomotor centre.

    Of these statements

    1. I is true but II is false

    2. both I and II are true

    3. I is false but II is true

    4. both I and II are false

  8. Consider the following statements: Periodic (Cheyne-Stokes) breathing is seen

    1. after voluntary apnoea.

    2. after voluntary hyperpnoea.

    3. at high altitude

    4. during wakeful states of adult human being

    Of these statements

    1. 1, and 2 are correct

    2. 3 and 3 are correct

    3. 2, 3 and 4 are correct

    4. 1, 3 and 4 arc correct

  9. Okasald fragments are short pieces of DNA replicated

    1. continuosly in the 5 ‘3’ direction

    2. discontinuosly in the 3 ‘-5’ direction

    3. continuosly in the 3 ‘5’ direction

    4. discontinuosly in the 5 ‘-3’ direction

  10. Clearance values of four different substances have been plotted against their plasma concentrations in the given graph. Clearance of which one of the following substances would correspond to the curve labelled 4 in the given graph? x-axis: Plasma concentration of the substance (mg/100 ml) y-axis: Clearance value (ml/rain)

    1. PAH

    2. Inulin

    3. Urea

    4. Glucose

  11. Fats are digested in the sequence

    1. a-β diglyceride, a monoglyceride, fatty acids, glycerol

    2. a-β diglyceride, β monoglyceride, fatty acids, glycerol

    3. a-? diglyceride, monoglyceride, fatty acids, glycerol

    4. a-? diglyceride, a monoglyceride, fatty acids, glycerol

  12. Oxidation of one molecule of acetyl Co-A in TCA cycle will liberate

    1. 12 ATP

    2. 15 ATP

    3. 24 ATP

    4. 30 ATP

  13. The codons UAA, UAG and UGA

    1. code for phenylalanine

    2. initiate protein synthesis

    3. elongate the protein chain

    4. signal the termination of protein synthesis

  14. Degeneracy of the genetic code denotes the existence of

    1. Condons consisting of only two bases

    2. codons that include one or more of the unusual bases

    3. multiple condons for a single amino acid

    4. base triplets coding for different amino acids

  15. Intermediates in citric acid cycle do not take part directly in

    1. gluconeogenesis

    2. transamination

    3. fatty acid synthesis

    4. glycogen synthesis