NCERT Class 11 Biology Transport in Plants Questions

VERY SHORT ANSWER TYPE QUESTIONS

1. Smaller, lipid soluble molecules diffuse faster through cell membrane, but the movement of hydrophilic substances are facilitated by certain transporters which are chemically ____________.

2. In a passive transport across a membrane, when two protein molecules move in opposite direction and independent of each other, it is called as ___________.

3. Osmosis is a special kind of diffusion, in which water diffuses across the cell membrane. The rate and direction of osmosis depends upon both ______________.

4. A flowering plant is planted in an earthen pot and irrigated. Urea is added to make the plant grow faster, but after some time the plant dies. This may be due to _______________ .

5. Absorption of water from soil by dry seeds increases the _____________, thus helping seedlings to come out of soil

6. Water moves up against gravity and even for a tree of 20m height, the tip receives water within two hours. The most important physiological phenomenon which is responsible for the upward movement of water is _______________________.

7. The plant cell cytoplasm is surrounded by both cell wall and cell membrane. The specificity of transport of substances are mostly across the cell membrane, because _________________.

8. The C4 plants are twice as efficient as C3 plants in terms of fixing CO2 but lose only _________ as much water as C3 plants for the same amount of CO2 fixed.

9. Movement of substances in xylem is unidirectional while in phloem it is bidirectional. Explain.

SHORT ANSWER TYPE QUESTIONS

1. Minerals absorbed by the roots travel up the xylem. How do they reach the parts where they are needed most? Do all the parts of the plant get the same amount of the minerals?

2. If one wants to find minerals and in the form they are mobilised in the plant, how will an analysis of the exudate help?

3. From your knowledge of physiology can you think of some method of increasing the life of cut plants in a vase?

4. Do different species of plants growing in the same area show the same rate of transpiration at a particular time? Justify your answer.

5. Water is indispensable for life. What properties of water make it useful for all biological processes on the earth?

6. How is it that the intracellular levels of K+ are higher than extracellular levels in animal cells?

7. Cut pieces of beetroot do not leave colour in cold water but do so in hot water. Explain.

8. In a girdled plant, when water is supplied to the leaves above the girdle, leaves may remain green for sometime then wilt and ultimately die. What does it indicate?

9. Various types of transport mechanisms are needed to fulfil the mineral requirements of a plant. Why are they not fulfilled by diffusion alone?

10. How can plants be grown under limited water supply without compromising on metabolic activities?

11. Will the ascent of sap be possible without the cohesion and adhesion of the water molecules? Explain.

12. Keep some freshly cut flowers in a solution of food colour. Wait for sometime for the dye to rise in the flower, when the stem of the flower is held up in light, coloured strands can be seen inside. Can this experiment demonstrate which tissue is conducting water up the stem?

13. When a freshly collected Spirogyra filament is kept in a 10% potassium nitrate solution, it is observed that the protoplasm shrinks in size:

 a. What is this phenomenon called?

b. What will happen if the filament is replaced in distilled water?

14. Sugar crystals do not dissolve easily in ice cold water. Explain.

15. Salt is applied to tennis lawns to kill weeds. How does salting tennis lawns help in killing of weeds without affecting the grass?

16. What is the chemical composition of xylem and phloem sap?

17. If you are provided with two tubes (A and B), where one is narrow and the other is relatively wider and if both are immersed in a beaker containing water as shown in the figure given on next page.

Please refer to attached file for NCERT Class 11 Biology Transport in Plants