Biology
Root hairs are the epidermal outgrowths of the outermost layer of roots. They are well-suited for absorption of water from soil due to which of the following features ?
P. Large surface area.
Q. Lower concentration of cell sap.
R. Semi permeable nature of the cell membrane.
- Only P
- Only Q
- Only P and Q
- Only P and R
Answer
Only P and R
Reason — The root hairs are well-suited for absorption of water from soil due to their larger surface area, higher concentration of cell sap, and semi permeable nature of the cell membrane.
Lower concentration of cell sap is not a structural feature. In fact, root hair cell sap is more concentrated than soil water, which helps water move into the cell by osmosis.
Related Questions
Which one of the following favours the fastest transpiration rate?
- A cool, humid, windy day,
- A hot, humid, windy day,
- A hot, humid, still day,
- A hot, dry, windy day.
Vinay has kept a small herbaceous plant in a test tube containing water. The surface of the water is covered by a layer of oil. After three hours, he observed that the level of water in the test tube has decreased. This is due to:
- Absorption
- Transpiration
- Wilting
- Both (1) and (2)
Xylem tissue forms a tubular passage to transport water and mineral salts from the roots to the aerial parts of a plant. It consists of different types of cells.
P. Sieve tubes and companion cells
Q. Wood parenchyma and wood fibres
R. Tracheids and vesselsWhich of the following are xylem components?
- Only P
- Only P and R
- Only Q and R
- All P, Q and R
Assertion (A): The food prepared by leaves is transported to all parts of the plant.
Reason (R): Roots are the underground parts of the plant which absorb food material from the soil.
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true but R is not the correct explanation of A.
- A is true but R is false.
- A is false but R is true.