Biology Today — January 2018

1. Glucose is not stored in plant due to
   (a) decrease in osmotic pressure
   (b) increase in osmotic pressure
   (c) increase in turgor pressure
   (d) decrease in turgor pressure.


2. All of the following statements are true except
   (a) Most herbaceous plant has 10-15% body weight as dry
   weight.
   (b) Water is often a limiting factor for plant growth and
   productivity in agriculture.
   (c) Water potential of pure water is zero if it is under external
   pressure.
   (d) Water channels in cell membrane are formed of 8 different
   types of aquaporins.


3. Which of the following is true regarding osmotic pressure?
   (a) It develops only in a confined system.
   (b) Minimum pressure which must be applied on osmotically
   active solution just to prevent endosmosis in it.
   (c) Maximum possible pressure which may develop in an
   osmotically active solution due to endosmosis.
   (d) All of these


4. Hydrous cobalt chloride paper appears as
   (a) pink (b) blue (c) orange (d) green.


5. Transpiration driven ascent of xylem sap depends mainly on
   which of the following physical properties of water?
   (a) Cohesion (b) Surface tension
   (c) Diffusion in gaseous phase only
   (d) Both (a) and (b)


6. Translocation of food in phloem can be explained by
   (a) pressure flow hypothesis
   (b) cohesion and tension theory
   (c) classical starch hypothesis
   (d) all of these.


7. For translocation of food, sugar is transferred to sieve tubes

TRANSPORT IN PLANTS

PRACTICE PAPER

CLASS

XI

This paper contains 50 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 : 50 × 4 = 200 Negative Marking (–1)

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

from mesophyll cells by

(a) facilitated diffusion (b) passive absorption

(c) active transport (d) diffusion.

8. Which of the following is a wrong statement?
   (a) Lenticular transpiration accounts is for < 1% of total
   transpiration.
   (b) ‘Transpiration is a necessary evil’ stated by Curtis.
   (c) Translocation of food is unidirectional.
   (d) Guttation takes place early in the morning when
   transpiration is lower than water absorption in some
   herbaceous plants.


9. Which of the following condition favours closure of stomata?
   (a) Increase in pH and ABA
   (b) Development of absorption lag
   (c) Increase in pH and increase in concentration of CO 2
   (d) Increase in pH and decrease in O.P. of guard cells


10. What would be the \P of a fully flaccid cell?
    (a) –3 (b) 1 (c) zero (d) +3


11. The main form of sugar transported through phloem is
    (a) glucose (b) fructose (c) sucrose (d) ribose.


12. When a cell is fully turgid, which of the following will be zero?
    (a) Turgor pressure
    (b) Wall pressure (c) Water potential
    (d) Osmotic pressure (solute pressure)


13. How many of the following statements are true?
    I. Osmosis is passage of solutes through semipermeable
    membrane from decrease in DPD to increase in DPD.
    II. Osmotic pressure is higher in halophytes than xerophytes.
    III. Egg membrane and cellophane paper are selectively
    permeable membranes.
    I V. If a cell kept in a solution increases in size, then the
    solution will be hypertonic.
    V. 1M NaCl has higher \w as compared to 1M sucrose.
    (a) 4 (b) 3 (c) 2 (d) 1