Question

Assertion: During apoplastic movement of water, water travels through the cells and their cytoplasm.
Reason: The symplastic movement of water occurs exclusively through the intercellular spaces and the walls of the cells.
A) Both assertion and reason are correct and reason is the correct explanation for assertion.
B) Both assertion and reason are correct but reason is not the correct explanation for assertion.
C) Assertion is correct but reason is incorrect.
D) Both assertion and reason are incorrect.

Answer 1

Hint:Let us first have a brief idea about the water transport pathway in plants. Water transport in plants occurs by the collective effort of connective tissues of the vascular system and individual cells. Water will be transported from roots to the tip of the plant either by symplastic pathway or by apoplastic pathway.

Complete answer:
Assertion: During apoplastic movement of water, water travels through the cells and their cytoplasm.
Explanation: Apoplastic pathway is one of the main water pathways in which the minerals and water flows in the upward direction through the apoplast to the xylem. The transportation of concentration of solutes to the organs of plants occurs by import from the xylem vessels, absorption from cells and export by phloem vessels. In the apoplast pathway of movement of water, crossing the cell membrane is excluded. Apoplastic movement is dependent on the difference in water gradient.

Reason: The symplastic movement of water occurs exclusively through the intercellular spaces and the walls of the cells.
Explanation: Symplastic movement of water includes the interconnected protoplast system. In this pathway, the water molecules move across the symplast that includes plasmodesmata and cytoplasm. Plasmodesmata is the tiny connection between the cytoplasm of neighbouring cells. The water flows through the cells of cytoplasm and the intercellular movement is through plasmodesmata.

Therefore the correct answer is option (D) Both assertion and reason are incorrect.

Note: The velocity of transportation is comparatively higher in apoplast than symplast. The greater portion of water movement occurs in the apoplastic pathway compared to symplastic pathway. The water flow resistance is higher in the symplastic pathway because the flow of water is restricted by the plasma membrane.