Plant Transport and Physiology

This is the correct option. In terrestrial plants, diffusion of oxygen and carbon dioxide occurs through stomata and lenticels. Stomata are the minute openings on the surface of leaves and lenticels are the openings present on the stems and roots of plants.

Epiphytic plants hang in air, so they cannot absorb water from soil.

"Hardening" refers to the preparation of the plants for a natural growth environment. Low light intensity and high humidity is used for the same.

 Xenia is the effect of pollen on endosperm. It is the effect such as increase in size on the embryo or endosperm of a plant  resulting from fertilisation with the pollen of a genetically distinct variety.

It is caused by the rapid shrinkage of motor cells of main pulvilus in which dynamic changes occur in actin cytoskeleton.

Osmosis is the net movement of solvent molecules through a partially permeable membrane into a region of higher solute concentration. Due to the low water potential and the presence of semi permeable membrane of the root hair cell, water enters the plant by the process of osmosis. This mechanism is responsible for the ability of plant roots to draw water from the soil.

Stomata are minute apertures on plants found typically on the outer leaf skin layer, also known as the epidermis. They consist of two specialized cells called guard cells that surround a tiny pore called a stoma. Their main function is to allow gases such as carbon dioxide, water vapour and oxygen to move rapidly into and out of the leaf.

Active transport is the movement of a substance across a cell membrane against its concentration gradient from low to high concentration. In all cells, this is usually concerned with accumulating high concentration of molecules that the cell needs such as ions, glucose and amino acids. If the process uses chemical energy such as from adenosine triphosphate (ATP), it is termed primary active transport. Secondary active transport involves the use of an electrochemical gradient.

Usually when a plant wilts, it is an indicative of lack of water or moisture . It also occurs due to the presence of some kind of toxin such as introduced by disease or poison. If the soil around the roots of a plant lacks water or the rate of loss of water is faster than the rate of absorption of water, the cells in the plant will contain less water and fail to support the plant. Therefore, it results in dropping of plant parts.

The protein molecules in the cell membrane receive signals from other cells or the outside environment and convert the signals to messages that are passed to the organelles inside the cell.

Capillary water is the water held in soil pores against gravity but available for plant absorption. It's the primary water source plants use through their roots. Hygroscopic water is too tightly bound, gravitational water drains away quickly, and 'inner space water' is not a standard scientific term.

Critical concentration in plant nutrition refers to the nutrient level at which plant growth begins to be limited or slowed down. Below this concentration, the plant shows deficiency symptoms and reduced growth. The other terms are not standard agricultural terminology.

Thermophilic organisms prefer high temperatures, while thermophobic organisms avoid them. Thermoduric plants can withstand or resist high temperature stress. This term is derived from 'thermo' (heat) and 'duric' (durable/hard), indicating heat resistance.

The elongation region (zone of elongation) is where cells actively expand and push the root tip through soil. The root cap protects but doesn't provide force. The zone of cell division adds cells, and maturation region is where differentiation occurs - neither provides penetration force.

The non-vascular plant usually grows in the moist and shady places. The moist environment is essential for easy uptake of the water, since they lack the vascular tissues like the xylem and the phloem.