The movement of water through the root layers is ultimately:
1. apoplastic along the walls
2. active transport by porins
3. symplastic in the endodermis
4. symplastic in the xylem
In the mycorrhizal symbiotic relationship, the root provides the fungus with:
| 1. Water | 2. Phosphorus |
| 3. N – containing compounds | 4. Sodium and potassium |
The greatest contribution of root pressure in water transport in plants most likely is that it:
| 1. | pushes water to the top at night |
| 2. | pushes water to the top of the plant when the rate of transpiration is low |
| 3. | re-establishes the continuous chain of water molecules in the xylem |
| 4. | pushes water into the endodermal cells changing the transport from apoplast to symplast |
Most of the water reaching the leaves:
1. is used in photosynthesis.
2. is used up in plant growth.
3. is lost by transpiration.
4. is stored in the petiole.
In a guard cell:
I. The outer walls are thick and elastic
II. Cellulose microfibrils are oriented longitudinally
1. Only I is correct
2. Only II is correct
3. Both I and II are correct
4. Both I and II are incorrect
You are asked to measure transpiration rates on both the surfaces of Sunflower leaf. The transpiration rate is expected to be:
1. Lesser on upper surface and more on lower surface
2. Lesser on lower surface and more on upper surface
3. Equal on both the surfaces
4. Zero on upper surface
Cohesion, adhesion and surface tension provide water with a high tensile strength that means that it:
1. is capable of rising in a thin tube
2. has a low specific heat
3. resists a pulling force
4. is a universal polar solvent
Consider the following:
I. Creation of pull for absorption and transport in plants
II. Supply of water for photosynthesis
III. Transport of minerals from leaves to all parts of a plant
IV. Cooling of leaf surface
V. Maintenance of shape and structure of plants by keeping the cells turgid
Functions of transpiration include:
1. All
2. All but III
3. All but V
4. All but III and IV
The evolution of C4 photosynthetic system is probably one of the strategies for:
| 1. | maximizing the availability of oxygen in spite of continuing high amount of water loss |
| 2. | maximizing availability of water in spite of continuing high amount of carbon dioxide loss |
| 3. | reducing the amount of water loss but leads to decreased availability of carbon dioxide |
| 4. | maximizing the availability of carbon dioxide while minimizing water loss |
Unlike water, all minerals cannot be passively absorbed by the roots. This is due to:
I. Minerals are present in the soil as charged particles
II. Concentration of minerals in soil is generally less than the concentration of minerals in roots
The correct statements are:
1. Only I
2. Only II
3. Both 1 & II are incorrect
4. Both 1 & II are correct
© 2024 GoodEd Technologies Pvt. Ltd.