Biology today

1. Which of the following is/are correct statement/s?
   (i) at high light intensity, chloroplast in mesophyll cells
   of leaf, lies perpendicular to incident light.
   (ii) In reduction steps of ‘calvin cycle’ to form one
   glucose molecule 12 aaaTP and 12 NTP and 12 NaDPh are
   consumed.
   (iii)OpuntiaOpuntiaOpuntia and sugarcane needs 30 and sugarcane needs 30 aaaTP and 12 NTP and 12 NaDPh
   to produce one glucose molecule.
   (iv)In maize plant c 3 -cycle operates in mesophylls of
   leaf.
   (v) Sorghum plant losses about half as much water as
   mustard plant looses for same amount of cO 2 fixed.
   (a) (ii), (iii), (iv) and (v) (b) (i), (ii), (iii) and (iv)
   (c) (ii), (iii) and (v) (d) all of these


2. Which of the following statement is incorrect?
   (a) ruBiscO and PEPcO need mg++ as a catalyst for
   their carboxylation action.
   (b) mg++ and cl– is needed for photolysis of h 2 O.
   (c) cO 2 is the major limiting factor for photosynthesis.
   (d) ‘Kranz anatomy’ is characteristic to plants showing
   ‘hatch and Slack’ pathway.


3. Site of photolysis of h 2 O in plant is indicated as

(a) stroma of chloroplast

(b) granum

(c) outer surface of thylakoid membrane

(d) membrane of thylakoid facing the lumen.

4. Quantum efficiency of photosynthesis is
   (a) 1/8 (b) 12.5%
   (c) 0.125 (d) all of these.
   5. how many of the given plants are c 4?
   maize, Sorghum, Opuntia, Helianthus, mustard,
   Sugarcane, Bryophyllum, Pennisetum
   (a) 4 (b) 5
   (c) 2 (d) 3
   6. Identify P, Q, r and S in the given diagram.

P

Q

S

R

HCO 3 Phosphoenol-

pyruvate

Phosphoenol-

pyruvate

Phosphoenol-

Transport Transport

C acidC acidC acid 44

C acidC acidC acid 44

Fixation bycalvin cycleFixation bycalvin cycleFixation by

C acidC acidC acid 33

CO 2

C acidC acidC acid 33

HCO

C acidC acidC acid

C acid

C acid

calvin cycle

C acid

(a) P-Bundle sheath cell, Q-regeneration,

r-Decarboxylation, S-carboxylation

(b) P-Bundle sheath cell, Q-regeneration,

r-Decarboxylation, S-Fixation

(c) P-mesophyll cell, Q-regeneration,

r-Decarboxylation, S-carboxylation

(d) P-Bundle sheath cell, Q-regeneration,

r-carboxylation, S-Fixation

Contributed by: Harpal Singh, Harpal’s Biology Classes, Chandigarh, 09781124215

SInGLe OpTIOn COrreCT

PRACTICE PAPER

CLASS

XI & XII

This paper contains 180 multiple choice questions. Each question has four choices (a), (b), (c) and (d), out of which ONLY ONE

is correct. (Mark only One Choice).

Marks : 180 × 4 = 720 Negative Marking (–1)