Biology
The root hairs are suited for absorbing water from the soil because:
- They have a large surface area
- They have a semi-permeable membrane
- They contain a solution of higher concentration than the surrounding water.
- All the three.
Answer
All the three
Reason — Root hairs are long and thin, so they can penetrate between soil particles. They have a large surface area for absorption of water, which increases the rate of absorption. Their cell membrane is semi-permeable, allowing water to enter by osmosis. The cell sap in the root hair cell is of a higher concentration as it contains more solutes compared to the surrounding soil water. This promotes water absorption.
Related Questions
Force responsible for the ascent of sap is:
- Capillary force
- Root pressure
- Transpirational pull
- All the three
Raisins swell when put in:
- Rain water
- Saline water
- Mustard oil
- Saturated sugar solution
Transpiration is defined as:
- the rise of water up to the stem of a plant.
- the elimination of water with dissolved water products.
- the loss of water as water vapour from the aerial parts of a plant.
- the loss of water as water vapour from the roots as well as the leaves of the plant.
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.