biology-today_2015-03

(Nora) #1

  1. an anther has 1200 pollen grains. how many Pmcs
    must have been there to produce them?
    (a) 1200 (b) 300 (c) 150 (d) 2400

  2. In onion root tip, during metaphase stage of mitosis, the
    number of kinetochores will be
    (a) 4 (b) 8 (c) 16 (d) 32.

  3. During which phase(s) of cell cycle, amount of DNa in a
    cell remains at 4c level if the initial amount is denoted
    as 2c?
    (a) G 0 and G 1 (b) G 1 and S
    (c) Only G 2 (d) G 2 and m

  4. Out of 38 molecules of aTP produced upon aerobic
    respiration of glucose, the break up in aTP production
    in glycolysis (P), pyruvate to acetyl-coa formation (Q)
    and Krebs’ cycle (r) is as follows :
    (a) P = 2, Q = 6, r = 30
    (b) P = 8, Q = 6, r = 24
    (c) P = 8, Q = 10, r = 20
    (d) P = 2, Q = 12, r = 24

  5. match the mineral in column-I with the enzyme activated
    by it in column-II and choose the correct option.
    Column-I Column-II
    a. magnesium I. alcohol
    dehydrogenase
    B. molybdenum II. Phosphoenol pyruvate
    carboxylase
    c. Zinc III. Nitrogenase
    (a) a - II, B - III, c - I (b) a - I, B - II, c - III
    (c) a - II, B - I, c - III (d) a - III, B - II, c - I

  6. Which of the following statements regarding cyclic flow
    of elelctrons during light reactions is false?
    (a) This process takes place in the stromal lamella.
    (b) aTP synthesis takes place.
    (c) NaDPh + h+ is synthesised.
    (d) It takes place only when light of wavelength beyond
    680 nm is available for excitation.

  7. Select the correct match of the digested products in
    humans given in column-I with their absorption site and
    mechanism in column-II.
    Column-I Column-II
    (a) Glycerol, fatty acids Duodenum, move
    as chylomicrons
    (b) cholesterol, maltose Large intestine,
    active absorption
    (c) Glycine, glucose Small intestine,
    active absorption
    (d) Fructose, Na+ Small intestine,
    passive absorption

  8. Select the correct order of reactions in glycolysis.
    a. conversion of 3-phosphoglyceraldehyde to 1,3-bis-
    phosphoglycerate
    B. conversion of 3-phosphoglyceric acid to 2-phospho-
    glycerate
    c. conversion of BPGa to 3-phosphoglyceric acid
    D. Splitting of fructose 1, 6-bisphosphate into dihydroxy
    acetone phosphate and 3-phosphoglyceraldehyde
    (a) D, c, a, B (b) B, c, a, B
    (c) B, D, a, c (d) D, a, c, B

  9. In the clotting mechanism pathway, thrombin activates
    factors
    (a) XI, VIII, V (b) XI, IX, X
    (c) VIII, X, V (d) IX, VIII, X.

  10. The pressure gradient, to facilitate inspiration and
    expiration in the human body, is generated using
    (a) intercostal muscles and trachea
    (b) diaphragm and bronchi
    (c) intercostal muscles and the bronchioles
    (d) intercostal muscles and diaphragm.

  11. Which of the following factor(s) increase blood pressure?
    (i) Increase of cardiac output
    (ii) constriction of blood vessel
    (iii) Increase of blood volume
    (iv) activation of parasympathetic nervous system
    (v) Inhibition of sympathetic nervous system
    (a) (i) and (ii) (b) (iii) and (iv)
    (c) (i), (ii) and (iii) (d) (i), (ii), (iv) and (v)

  12. If osmolarity of nephric filtrate in relation to blood
    plasma is represented as follows:
    hypertonic Isotonic hypotonic
    and different parts of nephron as follows:
    PcT - a; Descending limb - B;
    DcT - c; collecting duct - D; ascending limb - E;
    Then, identify the correct option for the osmolarity of
    nephric filtrate in different parts of the nephron?
    (a) a ; B ; c ; D ; E
    (b) a ; B ; c ; D ; E
    (c) a ; B ; c ; D ; E
    (d) a ; B ; c ; D ; E

  13. In the resting muscle fibre, tropomyosin partially
    covers
    (a) calcium binding sites on troponin
    (b) actin binding sites on myosin
    (c) myosin binding sites on actin
    (d) calcium binding sites on actin.

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