Tag: long distance transport of water

In the presence of NaCl in the environment causes exosmosis and removes water from the cell. Once the water leaves the elodea cell, the membrane collapses into the center of the cell with the other remaining organelles. At this point, the plasma membrane is clearly visible.

Water absorption takes place through root. There are two theories to explain the mechanism of water absorption. One is passive absorption and the other is active absorption. Osmotic theory of active water absorption was given by Atkins and Priestley. According to this theory, water is absorbed due to osmotic difference between soil water and tonoplasm. Water moves from soil to root xylem along the increasing gradient of suction pressure.

Xylem vessels are made up of a substance called lignin. In some xylem vessels contains lignocellulose which is the complex structure of lignin and cellulose also present in it. They are long hollow chains of which are made up of tough long dead xylem cells. Each of the vessels is interconnected to each other through a perforation in their common walls. Xylem vessels are hydrophobic in nature i.e, cell wall shows the greater affinity for water. With the help of this particular property only xylem vessel function as transportation of water and solutes from the roots to all parts of a plant. 

 Root pressure is the force in root region that helps to drive water or sap upwards into tracheary elements of xylem. Water is absorbed through the root hairs from the soil. When during low transpiration there is no transpiration pull that time root pressure increases and water moves upwards in xylem elements. Root pressure is actively push up the water to small height in the stem.

So the correct answer is 'Root pressure '.

Lotus have stomata on the upper surface of its leaves. Hence, Coating of Vaseline on its upper surface will hinder transpiration. 

When the concentrations of both the solution (cell sap as well surrounding solution) are same, there is no net movement in the cell. Such solutions are called isotonic solutions. Since it is specified that no change in volume occurs it means that the concentration of the cell sap will be same as that of the concentration of salt.

• Like animals, plants also respire all the time because their cells need energy, to stay alive, but plants can only photosynthesize when they are in the light. Photosynthesis happens in the chloroplasts of plant cells. 
• It produces glucose for use by the plant, and oxygen as a waste product. Respiration uses oxygen and produces carbon dioxide and water as a waste product.
  

Oxygen is a waste product of photosynthesis. While carbon dioxide is exhaled by the plants at night in absence of photosynthesis. Excess water is given out by transpiration.
So the answer is- all of these.

Plants eliminate some waste through diffusion. During the day, excess oxygen gas produced by photosynthesis is released through the stomata. Carbon dioxide produced by respiration is normally used up during photosynthesis. At night, however, as photosynthesis slows, carbon dioxide is not used up as fast as it is produced, and it is released as a waste product. Plants also release waste water by transpiration and guttation. 

Plants eliminate some waste through diffusion. During the day, excess oxygen gas produced by photosynthesis is released through the stomata. Stomata are microscopic pores in leaves. Carbon dioxide produced by respiration is normally used up during photosynthesis. At night, however, as photosynthesis slows, carbon dioxide is not used up as fast as it is produced, and it is released as a waste product. Plants also produce oxygen as a by-product of photosynthesis. The oxygen that is not used for respiration is also excreted through the stomata. Plants do not excrete gases through flowers, roots and seeds.