Classification is not a single-step process, but involves a hierarchy of steps, in which each step represents a rank or category. Each category, a unit of classification, represents a taxon. Taxonomical studies of all the known organisms have led to the development of certain common categories.
(a) Name and arrange the common categories in proper sequence in a hierarchy, from the lowest to the highest category
(b) Name the following:
(i) The family that includes lion, tiger and leopard, all belonging to the genus Panthera.
(ii) The order that includes the plant families Convolvulaceae and Solanaceae.

Taxonomic studies of various species of plants, animals and other groups of organisms are useful in forestry, agriculture, industry and in general in knowing our bioresources and their diversity. Biologists have established certain procedures and techniques to store and preserve the information as well as the specimens.
(a) Mention two such taxonomic aids each, where
(i) live specimens are available.
(ii) preserved specimens are kept.
(b) What does a couplet in the taxonomic keys represent?

All living phenomena are due to the underlying interactions, which result in emergent properties at higher levels of organisation. It is true in the hierarchy of organisational complexity at all levels.
(a) Give two examples to substantiate the above statement.
(b) Define living organisms based on this property

When we try to define 'living', we conventionally look for certain distinctive characteristics exhibited by living organisms. Some of them are 'defining' properties while some others are not 'defining' properties.
(a) Give four 'defining' properties of living organisms.
(b) Why is reproduction not considered an all inclusive defining characteristic of living organisms?