Photosynthesis; Introduction
Photosynthesis is the fundamental basis of competitive success in green plants and the principal organ of photosynthesis in higher plants is the leaf. It is the process in which …
PHOTORECEPTORS ABSORB LIGHT
Photoreceptors are deļ¬ned as pigment molecules that process the energy and informational content of light into a form that can be used by the plant. A pigment that contains …
COHESION TENSION THEORY
This theory was proposed by Dixon according to this theory a number of forces responsible for upward movement of sap in plants. The most widely accepted theory for movement …
TRANSPIRATION
Loss of water in the form of vapours from plant surface. The loss of water due to transpiration is quite high. Rather 98-99% of the water absorbed by a …
Water loss from Leaf
After water has evaporated from the cell surface into the intercellular air space, diffusion is the primary means of any further movement of the water out of the leaf. …
ROOT PRESSURE
If the stem of a young seedling is cut off just above the soil, the stump will often exude sap from the cut xylem for many hours. If a …
Diffusion
The net movement of molecules from region of high concentration to regions of low concentration that is, down the concentration gradient. Water molecules in a solution are not static …
WATER IN THE SOIL
The water content and the rate of water movement in soils depend to a large extent on soil type and soil structure. At one extreme is sand, in which …
WATER IN PLANT LIFE
Water makes up most of the mass of plant cells. Each cell contains a large water-filled vacuole. In such cells the cytoplasm makes up only 5 to 10% of …
Shape, Arrangement, and Size
It might be expected that bacterial cells, being small and relatively simple, would be uniform in shape and size. This is not the case, as the microbial world offers …