Ch 1The Living World — Class 11 Biology, concept-first.

The living world confronts us with wonder at every turn. Life exists in a staggering range of forms and thrives in the most extraordinary settings — icy mountain slopes, dense deciduous forests, the o…

Look around and you will find life in astonishing variety — potted plants, insects, birds, pets and other animals, alongside countless organisms too small for the naked eye to see.

Classification is not a single step but a hierarchy of steps, each step representing a rank or category.

In taxonomy, a species is a group of individual organisms that share fundamental similarities. What sets one species apart from another closely related one are distinct morphological differences — dif…

A genus is a group of closely related species that have more characters in common with one another than they share with the species of any other genus.

A family is the next category above genus and gathers together a group of related genera. Because it spans several genera, a family shares fewer similarities among its members than are found within a…

Order is a taxonomic rank that sits above family. While the lower categories such as species, genus and family are recognised on the basis of a fairly large set of shared characters, the higher catego…

A class is a taxonomic category that groups together related orders — orders that share a set of common features are placed in the same class.

Phylum is the taxonomic category that lies just above class. Several classes that resemble one another in a few basic features are grouped together to form a phylum.

Kingdom is the highest taxonomic category. All the animals belonging to the various phyla are gathered into a single highest category — the Kingdom Animalia.

The living world is remarkably rich in variety. Millions of plants and animals have already been identified and described, yet a large number still remain unknown.

Higher-order thinking / exemplar-style practice problems.