If the guard cells and surrounding epidermal cells of a leaf were deficient in potassium ions, the rate of photosynthesis would
3. Remain constant
4. Cannot be predicted
Pick the incorrect statement
1. Guard cells help balance the photosynthesis-transpiration compromise.
2. Water tension in a transpiring plant will exert a pull on water molecules lower down in the plant's vascular system.
3. Plants that live in deserts have adapted to constant water stress by using hydrophilic colloids to increase the water potential of their tissues.
4. C 3 plants can fix double the carbon dioxide for half the water transpired.
What seems to be the most valid statement about root pressure?
1. It is the positive pressure responsible for transport of water most commonly.
2. It may provide a considerable push to the water column during transport.
3. It may help re establish the broken water columns during transpiration
4. Its effect is most observable during mid day
A structural attribute of guard cells that aid in its effective functioning is
1. Large cell size
2. Radial micellation in walls
3. Thick walls
4. All of the above
Not an aid to water absorption is
1. The high surface area of roots
2. High water potential of root hair cells
3. Thin cellulosic walls of root hair zone
4. Low concentration of solutes in the epidermal cells
The presence of free starch in the cell will serve to
1. Increase its water potential
2. Decrease its water potential by virtue of solutes
3. Increase solute potential by virtue of solutes.
4. Decrease its water potential by virtue of matric potential.
The water is free to move between the cells except through the
Translocation does not involve
1. a pressure difference between the source and the sink
2. Same velocity of transport of all substances together.
3. Transport of each substance according to its concentration gradient
4. None of the above
Continuity of protoplasm in sieve elements is maintained through
1. Cytoplasmic strands
2. P proteins
Which is not an advantage of transpiration.
1. Maintains shape of cells by keeping them turgid
2. Cools down plant surfaces by evaporative cooling
3. Transports minerals.
4. None of the above.