NEET Practice Questions (MCQs) with Answers & Solutions

Table 1.1 shows 'Angiospermae' under the 'Phylum/Division' column for Mango. Dicotyledonae is a Class, Poales is an Order, and Hominidae is a Family. In case of plants, the term 'Division' is used instead of 'Phylum'.

The NCERT states, 'Each category, referred to as a unit of classification, in fact, represents a rank and is commonly termed as taxon (pl.: taxa).' It further adds, 'These taxonomic groups/categories are distinct biological entities and not merely morphological aggregates.'

The NCERT states, 'However, taxonomists have also developed sub-categories in this hierarchy to facilitate more sound and scientific placement of various taxa.'

The text clearly states, 'All organisms, including those in the plant and animal kingdoms have species as the lowest category.'

The NCERT defines, 'The branch of knowledge dealing with these aspects is referred to as taxonomy.' It also distinguishes taxonomy from systematics by stating 'The scope of systematics was later enlarged to include identification, nomenclature and classification. Systematics takes into account evolutionary relationships between organisms.'

The NCERT states, 'Classification is not a single step process but involves hierarchy of steps in which each step represents a rank or category. Since the category is a part of overall taxonomic arrangement, it is called the taxonomic category and all categories together constitute the taxonomic hierarchy. Each category, referred to as a unit of classification, in fact, represents a rank and is commonly termed as taxon (pl.: taxa).'

From Table 1.1, for Mango, 'Dicotyledonae' is listed under 'Class'. Similarly, for Wheat, 'Monocotyledonae' is listed under 'Class'. Therefore, they represent the Class level.

From Table 1.1, 'Musca' is listed under 'Genus' for Housefly and 'Mangifera' is listed under 'Genus' for Mango. Thus, both are genera.

The NCERT states, 'Hence, all these - 'Dogs', 'Cats', 'Mammals', 'Wheat', 'Rice', 'Plants', 'Animals', etc., are convenient categories we use to study organisms. The scientific term for these categories is taxa. Here you must recognise that taxa can indicate categories at very different levels. 'Plants' – also form a taxa. 'Wheat' is also a taxa.'

According to the NCERT text, 'Every force encountered in mechanics does not have an associated potential energy. For example, work done by friction over a closed path is not zero and no potential energy can be associated with friction.' Gravitational, spring, and electrostatic forces are all conservative forces and thus have associated potential energy functions.