Plant Transport and Physiology

Adaptations are special features that allow a plant or animal to live in a particular place or habitat.

This particular movement is observed in twiners and climbers. This results in curvature and helps in twinning around the support.

Yes, it is the correct answer. The process of preparation of food in plants does not take place with the help of osmosis. Photosynthesis takes place in the presence of sunlight with chlorophyll, water and air.

Stomata are the openings that are generally present on the lower surface of the leaves through which the gases and water vapour diffuse in and out easily. The oxygen diffuses in through the stomata and then enters the leaf cells. Similarly, the carbon dioxide produced by the leaf cells diffuses out through the stomata.

Nitrate reduction in plants is carried out in two steps. Nitrate is first reduced to nitrite (NO²⁻) in the cytosol by nitrate reductase using NADH or NADPH. Nitrite is then reduced to ammonia in the chloroplasts (plastids in roots) by a ferredoxin-dependent nitrite reductase. In photosynthesising tissues, it uses an isoform of ferredoxin (Fd1) that is reduced by PSI, while in the root, it uses a form of ferredoxin (Fd3) that has a less negative midpoint potential and can be reduced easily by NADPH. In non-photosynthesising tissues, NADPH is generated by glycolysis and the pentose phosphate pathway. In the chloroplasts, glutamine synthetase incorporates this ammonia as the amide group of glutamine using glutamate as a substrate. Glutamate synthase (Fd-GOGAT and NADH-GOGAT) transfer the amide group onto an 2-oxoglutarate molecule producing two glutamates. Further transaminations are carried out to make other amino acids (most commonly aspargine) from glutamine. 

Condensation is the change of water from its gaseous form (water vapour) into liquid water. Perspiration, also known as sweating or diaphoresis, is the production of fluids secreted by the sweat glands in the skin of mammals. Respiration is defined as the movement of oxygen from the outside air to the cells within tissues, and the transport of carbon dioxide in the opposite direction. Transpiration is the process by which moisture is carried through plants from roots to small pores on the underside of leaves, where it changes to vapour and is released in the atmosphere. 

When stomata are sealed or closed, transpiration and gas exchange (including CO2 intake for photosynthesis) are greatly reduced or stopped. However, guttation can still occur because it is driven by root pressure and takes place through specialized structures called hydathodes, not through stomata. Guttation typically occurs at night or early morning when transpiration is minimal.

Water movement up the xylem vessel is driven by transpiration pull and cohesion-tension mechanism, not osmosis. Osmosis is the movement of water across a semi-permeable membrane from low to high solute concentration. The other options (A, B, D) all involve water crossing cell membranes (root hair cells), which do involve osmosis.

The condition required for callus growth is 25+/-2^oC light.

 Excess water is excreted from plants through the stomata in leaves.  Plants can get rid of excess water by transpiration and guttation.

Waste products are stored as resins in old xylem plants. Some plant wastes are very useful to human beings, e.g. rubber, latex, gum, resins and essential oils like eucalyptus or sandalwood oil. 

Opening and closing of stomata in angiosperms is due to changes in turgor pressure of guard cells. As the turgor pressure of the guard cells changes, the opening and closing of stomata occurs.

Organic substances such as sugars translocated in the phloem, can be demonstrated by ringing the stem.

Molybdenum metal involves in nitrogen metabolism including nitrogen fixation. Molting and necrosis of leaves is known as Whiptail disease. Whiptail disease of crucifers is caused by the deficiency of molybdenum metal. 

The bundle sheath cells have no intercellular spaces.