Exercises

Question:- 1. What are the advantages of classifying organisms?

Answer:- Following are the advantages of classifying organisms:

• It makes the study of various organisms much easier.
• It tells us about the inter-relationship among the different organisms.
• It helps us understanding the evolution of different organisms.
• It helps environmentalists to develop new methods of conservation of various plants and animals.

Question:- 2. How would you choose between two characteristics to be used for developing a hierarchy in classification?

Answer:-  The basis of the start of the hierarchy will be formed by the Gross character while the Fine character will build the foundation of later phases.

Question:- 3. Explain the basis for grouping organisms into five kingdoms.

Answer:- The basis for grouping organisms into five kingdoms are following:-

1. Number of cells
2. Layer of cells
3. Presence or absence of cell wall
4. Mode of nutrition
5. Level Of organization

Question:- 4. What are the major divisions in the Plantae? What is the basis for these divisions?

Answer:- The major divisions in Kingdom Plantae are:

• →Thallophyta
• → Bryophyta
• → Pteridophyta
• → Gymnosperms
• → Angiosperms

These divisions are based on the following criteria:-

Whether the plant body has well-differentiated, distinct components; whether the differentiated plant body has particular tissues for transporting water and other substances; and whether the seeds are encased within fruits.

Question:- 5. How are the criteria for deciding divisions in plants different from the criteria for deciding the subgroups among animals?

Answer:- The basic structure of a plant’s body is a major criterion for distinguishing Thallophytes from Bryophytes. Aside from that, the presence or lack of seeds is a significant criterion. Gymnosperms and angiosperms are further divided based on whether or not the seeds are coated. It is self-evident that the morphological trait serves as the foundation for plant classification.

Animal taxonomy is based on smaller structural differences. As a result, cytology takes the role of morphology as the foundation. Animals are classed depending on their cell layers and whether or not they have a coelom. Animals are placed higher in the hierarchy based on the presence or lack of minor traits, such as the presence or absence of four legs.

Question:- 6. Explain how animals in Vertebrata are classified into further subgroups.

Answer:- Pisces and Tetrapoda are the two superclasses of vertebrates. Pisces animals have a streamlined physique with fins and tails to help them swim. Tetrapoda animals have four limbs for locomotion.

Tetrapoda is further divided into the following groups:

(a) Amphibia: These animals have evolved to live both in water and on land. When submerged, it is possible to breathe oxygen through the skin.

(b) Reptilia: Crawling animals that sire offspring. Extreme temperatures are difficult for skin to survive.

(c) Aves: The forelimbs of Aves have been modified into wings to aid in flight. There are beaks present. Feathers cover the entire body.

(d) Mammalia: Mammary glands are present to provide nourishment to the young. Hair grows on the surface of the skin. The majority of the creatures are viviparous.