Objective Questions

Question. In root endodermis there is one way active transport of ions because of presence of
(a) pericycle
(b) suberin layer
(c) cortex
(d) cellulosic layer

Question. Translocation of food in flowering plants occurs in the form of
(a) starch
(b) glyceraldehyde
(c) glucose
(d) sucrose

Question. Bidirectional translocation of minerals takes place in
(a) xylem
(b) phloem
(c) parenchyma
(d) cambium

Question. The hypothesis accepted for the translocation of sugar from source to sink is__________.
(a) pressure gradient
(b) pressure flow hypothesis
(c) mass flow hypothesis
(d) both (b) and (c)

Question. Water in the adjacent xylem moves into the phloem by the process of
(a) facilitated diffusion
(b) acute transport
(c) simple diffusion
(d) osmosis

Assertion/Reason Type Questions

In the following questions, a statement of Assertion is followed by a statement of Reason.
(a) If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion.
(b) If both Assertion and Reason are true but the Reason is not the correct explanation of the Assertion.
(c) If Assertion is true but Reason is false.
(d) If both Assertion and Reason are false.

Question. Assertion : In symport both molecules cross the membrane in the same direction at the same time.
Reason : In antiport both molecules move in the opposite direction.

Question. Assertion : Osmosis is a special type of diffusion through a semipermeable membrane.
Reason : The net rate and direction of osmosis depends upon the pressure gradient.

Question. Assertion : Cohesion, adhesion and surface tension give high tensile strength to water.
Reason : Capillarity is aided by small diameter of the tracheary elements.

Critical Thinking Type Questions

Question. Cell A and cell B are adjacent plant cells. In cell A, ψ_s = – 20 bars and ψ_p = 8 bars. In cell B, ψ_s = – 12 bars and ψ_p = 2 bars. Then
(a) water moves from cell A to cell B.
(b) there is no movement of water between cell A and cell B.
(c) water moves from cell B to cell A.
(d) equal amount of water is simultaneously exchanged between cell A and cell B.

Question. A boy is studying transport of a certain type of molecules into cell. He finds that transport slows down when the cells are poisoned with a chemical that inhibits energy production. Under normal circumstances the molecules studied by the boy is probably transported by
(a) simple diffusion
(b) osmosis
(c) active transport
(d) facilitated diffusion

Question. Water will move from its region of higher chemical potential to its region of lower chemical potential until
(a) equilibrium is reached.
(b) amount of both solvent and solute in both regions become equal.
(c) solvent amount in both regions become equal.
(d) solute amount in both regions become equal.

Question. The net direction and rate of osmosis depends on both the ‘X’ and ‘Y’. Identify ‘X’ and ‘Y’.
(a) X – Solute; Y – Solvent
(b) X – Pressure potential; Y – Solute potential
(c) X – Water potential; Y – Pressure gradient
(d) X – Pressure gradient; Y – Concentration gradient

Question. A cell is said to be flaccid when
(a) there is no net flow of water towards the inside or outside.
(b) the external solution balances the osmotic pressure of the cytoplasm.
(c) water flows into the cell and out of the cell and are in equilibrium.
(d) the external solution is more dilute than the cytoplasm.