Cacti are adapted to hot and dry conditions by having no leaves and their stem makes photosynthesis offering a small surface area for evaporation, their stomata are closed during the day, they store water in their tissues succulent. Normally the red blood cells of a trout are oval and measure 13. When seen under the microscope what would be observed in a and b? If you do not have Microsoft Word installed see for advice on how to view them. It goes inside xylem vessels up the stem. Can this experiment demonstrate which tissue is conducting water up the stem? The carbohydrates synthesized in leaves and other green tissues are transported to roots and other non-green parts of the plant through phloem. The hollow tubes act like pipes allowing water and dissolved minerals to flow through them.
Roots obtain oxygen from air spaces in the soil. Transports food substances wherever they are needed. Their large surface areas allow gases to travel into their cells by diffusion, and once inside the cell diffusion is sufficient to cover the small distances from one part of the cell to the other. How does this hormone overcome stress conditions? They develop from cylindrical cells arranged end to end, in which the cytoplasm dies and the cell walls between adjoining cells breaks down leaving a dead empty tube. Which of the following plant material, is an efficient water imbibant? A biologist named Stephen Hales described how he carried out an investigation in 1727. Oxygen is mainly transported in the A. The heat from the sun causes the water to evaporate, setting the water chain in motion.
This is because water molecules stick to each other. The role of the stomata: they help to control the balance between loss of water vapour and uptake of carbon dioxide. These questions are more demanding and test Interpretation of data I , Hypothesis formulation and design H , Experimental design E , Application of biological information A , Comprehension of scientific articles C as well as simple recall R. Special carrier proteins in the root hair cell carry the mineral ions against their concentration gradient. Do you think it is reversible? Why are they not fulfilled by diffusion alone? Which of these would need active transport? Which of the following processes need energy? Potometer works on the principle of a Osmotic pressure b Root pressure c Amount of water absorbed equals the amount transpired d potential difference between the tip of the tube and that of the plant. Trace the movement of the labelled carbon dioxide.
This negative water pressure that occurs in the roots will eventually result in an increase of water uptake from the soil. Reproduced by permission of New Scientist a The function of red blood cells is to transport oxygen. Similar to the circular system in humans, the xylem and phloem tissues extend throughout the plant. Avoid water loss which may cause wilting. Transports water and salts in 1 direction.
In addition, the more complex organisms may be covered by shells, scales, feathers, skin or hairs which do not allow diffusion. Deciduos trees: they lose every evaporation surface when water may be unavailable. The cells lose their nuclei. Water is absorbed by passive mechanism; whereas the minerals are absorbed by active mechanism. Finally it reaches the mesophyll cells in the leaf.
Xylem The cell walls are thickened with lignin which makes it strong and impermeable. In humans, the blood circulatory and lymphatic systems transport body fluids. Water enters in plants through their root hair cells by osmosis. In leaves and green stems gases enter and leave through the stomata. Comment on the upward movement of water given the intermolecular hydrogen bonding in water. Which one of the following maintains a transpiration stream in flowering plants? Cells shrink in hypotonic solutions and swell in hypertonic solutions.
This creates a pull by replacing the water that has evaporated. Correct answers are indicated as well as explanations of the reasons for rejecting the alternatives. Urea is added to make the plant grow faster, but after some time the plant dies. During daylight stomata are open allowing water vapour to diffuse out so, although the effect is not direct: If the air is very humid it has a lot of water vapour and it can accept little more so transpiration slows down. But plants survive under flooded condition.
End of Chapter Questions Page 103 8. Which one of the following theories for ascent of sap was proposed by eminent Indian scientist J. The cells form elongated tubes called sieve tube elements. Transportation In Plants And Trees Transportation in plants and its efficiency are amazing. The movement of food substances through the plant is called translocation. Later they branch off into the branches and then branching even further into every leaf, like spider webs. Presence of a semipermeable is a pre-requisite for this process to occur.
Read the extract and then answer the questions which follow. From where does this hormone get released in leaves? There are two different types of thin tubes or transport tissues which make up the vascular bundles in plants. They also react to water stress: if the leaf is losing water by transpiration faster than it is being taken up by the root they start to close to delay the wilting. In still air the region round a transpiring leaf will have a lot of water vapour so transpiration slows down. Here we have covered Important Questions on Transport in Plants for Class 11 Biology subject.
Which of the following experiment is called physiological demonstration of osmosis? Prevent air from entering the xylem vessels D. Phloem tubes are made up of columns of living cylindrical cells. At regular intervals the solutions surrounding the roots were tested for radioactive potassium ions. The force which mostly help water to move up a tall plant are A. Process Transpiration Translocation Structure Cylindrical cells arranged end to end, in which the cytoplasm dies and the cell walls between adjoining cells breaks down leaving a dead empty tube with strengthened cell walls. Now one might wonder how water could withstand the tensions pulled up by a tree.