Q5. Define (i) phylum, (ii) class, (iii) family, (iv) order, (v) genus (NCERT Exercise Q9).
(i) Phylum: related classes, such as those of fishes, amphibians, reptiles, birds and mammals in Chordata (division for plants). (ii) Class: related orders, such as Primata and Carnivora in Mammalia. (iii) Family: a group of related genera, such as Panthera and Felis in Felidae. (iv) Order: an assemblage of families with a few similar characters, such as Felidae and Canidae in Carnivora. (v) Genus: an aggregate of closely related species, such as lion, tiger and leopard in Panthera.
Q6. Illustrate the taxonomic hierarchy with a plant and an animal (NCERT Exercise Q10).
Wheat: species Triticum aestivum, genus Triticum, family Poaceae, order Poales, class Monocotyledonae, division Angiospermae, kingdom Plantae. Man: species Homo sapiens, genus Homo, family Hominidae, order Primata, class Mammalia, phylum Chordata, kingdom Animalia (NCERT Table 1.1 and Section 1.2.7).
Q7. What common features place fishes, amphibians, reptiles, birds and mammals in one phylum?
The presence, at least during development, of a notochord and a dorsal hollow neural system; they form the phylum Chordata (NCERT pages 7–8).
Q8. In which family does NCERT place Solanum, Petunia and Datura?
Solanaceae (NCERT page 7).
Q9. On what features are plant families characterised?
On both vegetative and reproductive features of the plant species (NCERT page 7).
Q10. Assertion: the higher the category, the harder it is to determine its relationship to other taxa at the same level. Reason: going up the hierarchy, the number of common characteristics decreases. Are both true, and does the reason explain the assertion?
Both are true, and the reason explains the assertion: with fewer shared characters, relationships at higher levels are harder to work out. (NCERT page 8 gives both statements; the link is the natural reading.)
Q11. Which categories are lowest and highest in NCERT’s seven-rank hierarchy?
Among these seven ranks, species is lowest and kingdom highest (NCERT pages 6 and 8).
Q12. Mango and wheat are both in Angiospermae. At which level are they first separated, according to NCERT Table 1.1?
At the class level: mango is in Dicotyledonae and wheat in Monocotyledonae.