A pollen tube is a tubular structure produced by the male gametophyte (pollen grain) of seed plants when it germinates at the top of the stigma. It’s elongation is an integral stage in the plant life cycle as it brings the sperm nuclei towards the ovule and causes to happen fertilization. …

Semantides are information-carrying molecules. Semantides provide taxonomic data not on the basis of presence or absence, but in terms of sequences, ratios or percentages,. Semantides are of three types, viz., Primary semantide – DNA Secondary semantide- RNA Tertiary semantides – Proteins Sometimes the semantides together with the larger polysachharides, are …

The chemical substances which have been found very useful in taxonomy are secondary metabolites. Secondary metabolites (secondary plant products) perform non-vital (or at least non- universally vital) functions, and are less widespread in plants. The restricted occurrence of these metabolites among plants renders them valuable as taxonomic information. Secondary plant …