Transport in Plants Test - 2

Transport of water and mineral in plant take place through xylem tissue present in vascular bundles. Vessels and tracheids are main water conducting elements of xylem.

Root hairs absorb water from soil with the help of suction pressure created due to concentration difference of water and mineral ions present in soil.

Some carrier or transport proteins allow diffusion only if two types of molecules move together. In a symport, both molecules cross the membrane in the same direction.

Diffusion rates are affected by the gradient of concentration, the permeability of the membrane separating them, temperature and pressure.

The porinsare proteins that form huge pores in the outer membranes of the plastids, mitochondria and some bacteria allowing molecules up to the size of small proteins to pass through.

Water is essential for all physiological activities of the plant and plays avery important role in all living organisms. It provides the medium in which most substances are dissolved.

Diffusion pressure deficit is equal to osmotic pressure minus water potential. Higher the DPD more faster osmosis will occur.(DPD = OP – WP).

Two cells close to each other are called contiguous cells. Movement of water from one cell to other depends upon Diffusiion pressure deficit (DPD). DPD depends upon osmotic pressure and water pressure. So, movement of water from A to B will take place.

Transpiration takes place through stomata. Decrease in light intensity closes the stomata that ultimately results into reduction in rate of transpiration.