Assertion(A) : The water is absorbed by the root and moves into the stem. Reason (R) : From root hair cell, water directly moves to xylem cells.

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Q: 96 (CDS-I/2004)
Assertion(A) : The water is absorbed by the root and moves into the stem.
Reason (R) : From root hair cell, water directly moves to xylem cells.

question_subject: 

Science

question_exam: 

CDS-I

stats: 

0,4,40,33,7,4,0

keywords: 

{'root hair cell': [0, 0, 1, 0], 'xylem cells': [0, 0, 1, 0], 'root': [12, 0, 4, 3], 'water': [65, 15, 80, 129]}

The correct answer is option 3: A is true, but R is false.

Explanation:

Assertion (A) states that water is absorbed by the root and moves into the stem, which is true. Roots have root hairs that increase the surface area for water absorption, and water is absorbed through the process of osmosis. It then moves upward through the xylem tissue in the stem.

Reason (R) states that water directly moves to xylem cells from root hair cells, which is false. Water does not directly move from root hair cells to xylem cells. After absorption, water travels across the root cortex through the apoplast or symplast pathways and enters the xylem vessels or tracheids in the root. From there, it moves upward through the xylem to reach the stem and other parts of the plant.

Therefore, while both the assertion and reason are individually true, the reason does not provide the correct explanation for the assertion. Hence, option 3 is the correct answer.

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