Change and the World Changes for You

Q1. Describe the importance of classification.
Ans. Classification is important because of the following reasons :–
1. By classification we recognises the basic taxonomic units or species.
2. It tells us about the resemblances and relationships between various organisms.
3. It helps in understanding the evolution of organisms, as it gives us most of the information permitting a reconstruction of phylogeny of life.
4. It has great role in many fields like agriculture, public health and environmental biology. Exact identification of harmful pests, disease vectors a made possible which makes the control of disease much easier.
5. Several ornamental plants have been introduced by horticulturists due to proper identification and nomenclature.
6. It also gives us a fair idea about the vast number of life forms and we are able to understand diversity among living organisms in a much better way.
 
Q2. Give a brief account of Whittaker’s five kingdoms of life.
Ans. Whittaker divided all the life forms into five kingdoms, which are Monera, Protista, Plantae, Fungi and Animalia.
1. Kingdom Monera—Prokaryotes Bacteria and Blue green algae.
2. Kingdom Protista—Unicellular eukaryotes having widely diverse life styles. Protists act as the precursors from which higher forms–Plantae, Fungi and Animalia–arose.
3. Kingdom Fungi—Eukaryotic, hetertophic organisms with assimilative nutrition, e.g. Rhizopus.
4. Kingdom Plantae—Eukaryotic multicellular, photosynthetic organisms, Green multicellular plants which are autotrophic and support life on the earth.
5. Kingdom Animalia—Eukaryotic multicellular consumers characterised by ingestive nutrition.
 
Q3. What are fungi ? What do you know about Lichens ?
Ans. Fungi are heterotrophic eukaryotic organisms which get nutrition from dead and decaying organic material by the process of absorption.

Many of them have the capacity to become multicellular organisms at certain stages in their lives. Their cell-wall is made of a...