Category: Biology

Venation: The arrangement of the veins in the lamina is called venation.  Depending on the arrangement of the veins and veinlets, venation may be of two main types – …

The leaf: The leaf is the green flattened structure which develops from the node of the stem or branch of a plant.  It is regarded as the most important …

Stem modification: Besides their normal functions, sometimes stem of some plants serve certain special functions, for which they undergo modification called modified stems.  All the three types – aerial, …

The stem: The stem is the ascending organ of the plant which originates from the plumule of an embryo and grows upwards to the source of light.  It can …

The Root: Root is the descending organ of the plant, which grows away from light.  It is usually white in colour in young stage and later on, may become …

Inflorescence The arrangement of flowers on a branch system is known as inflorescence.The inflorescence axis bearing the flower is known as peduncle and the stalk of individual flower is …

Cytokinin Cytokinins are plant growth hormones which are basic in nature, either aminopurine or phenyl urea derivatives that promote cytokinesis or cell division.  Cytokinin have little or no effect …

Auxin: Auxins are weakly acidic growth hormones having an unsaturated ring structure.  They are capable of promoting cell elongation, especially of shoots. Discovery: Charles Darwin (1880) discovered the existence …

Gibberellins Gibberellins are weakly acidic growth hormones which cause cell elongation of intact plants in general and increased internodal length of genetically dwarfed plants in particular. Discovery: Japanese rice …

Photoperiodism: Photoperiodism is the response of the plants to the relative lengths and alternation of light and dark periods for initiation of their flowering.  The plant processes like flowering, …