What is the pathway taken by water from the soil to the leaf?
A) root hair cells → root cortex → mesophyll → xylem
B) root hair cells → root cortex → xylem → mesophyll
C) root cortex → root hair cells → mesophyll → xylem
D) root cortex → root hair cells → xylem → mesophyll
▶️ Answer/Explanation
Ans: B
The correct pathway of water from the soil to the leaf is:
- Root hair cells absorb water from the soil.
- Water moves through the root cortex (via osmosis and apoplastic/symplastic pathways).
- It enters the xylem (vascular tissue) for upward transport.
- Finally, water diffuses into mesophyll cells in the leaf for photosynthesis.
Option B is correct because it follows this sequence. The other options misorder the steps (e.g., xylem cannot come after mesophyll, as xylem transports water to leaves).
Which statement about plant support is correct?
A) The pressure of water inside the cells presses inwards on the cell walls.
B) The pressure of water inside the cells presses outwards on the cell walls.
C) The pressure of water outside the cells presses inwards on the cell walls.
D) The pressure of water outside the cells presses outwards on the cell walls.
▶️ Answer/Explanation
Ans: B
Plant cells maintain their rigidity due to turgor pressure, where water inside the vacuole presses outwards against the cell wall. This creates structural support, making option B correct.
Incorrect options: A (inward pressure would collapse the cell), C/D (external water pressure does not provide primary support). Thus, the answer is B.