Question 1

What are the advantage of classifying organisms?

Accepted Answer

Earth is inhabited by more than millions of living organisms. It is impossible for an individual to name and and memorise each of these living organisms. Hence, a system is required to categorise these organisms into groups for better understanding. These arrangement in groups is nothing but a way to classify an organism on the basis of similarity it shares with other organism or group of organisms. Classifying an organism also helps us to study the course of evolution.

Question 2

How would you choose between two characteristic to be used for developing a hierarchy in classification?

Accepted Answer

For classifying an organism in a hierarchical fashion, the most fundamental and visible character is first taken into consideration. For example- plants differ from animals in having chloroplast and lacking locomotion, lacking a cell wall. But, only locomotion is considered as the most basic characteristic of classification. After choosing the fundamental, basic characteristic one can further classify the organism on the basis of the first feature chosen.

Question 3

Explain the basis for grouping organisms into five kingdoms.

Accepted Answer

Basis Of Clasiffication:(a) Number of cells(b) Layer of cells(c) Presence or absence of cell wall(d) Mode of nutrition(e) Level Of organization

Question 4

What are the major divisions in the Plantae? What is the basis for these divisions?

Accepted Answer

Kingdom Plantae are divided into 5 major divisions: Thallophyta, Bryophyta, Pteridophyta, Gymnosperms and Angiosperms. The kingdom Plantae is classified on the basis of:1. Whether the plant body is differentiated or undifferentiated.2. Whether the plant produces seeds or not.3. Whether the seeds produced are naked or enclosed within the fruits.4. Whether the differentiated plant body possesses specialized tissue for water and food transportation.

Question 5

How are the criteria for deciding divisions in plants different from the criteria for deciding the subgroups among animals?

Accepted Answer

Classification of plant is different than the classification of animals. In plants, classification is based on the morphology of the plants (i.e., differentiated or undifferentiated plant body, with or without seeds, naked seeds or seeds inside fruits, etc) whereas in animals, classification is mainly on the basis body design of an animal (i.e., presence or absence of a notochord).

Question 6

Explain how animals in Vertebrata are classified into further subgroups.

Accepted Answer

Vertebrates are classified into further subgroups on following bases:1. Pisces: Typically lives in water. It has a streamlined body. Locomotion is carried out with the help of muscular tail. Body is covered with scales. Paired gills are present; which can breathe oxygen dissolved in water. Animals are cold blooded. They lay eggs. Possesses 2 chambered heart.2. Amphibia: These animals can live both, on land and in water. The animals breathe through skin when in water and through lungs when on land. Animals are cold-blooded.3. Reptilia: Crawling movement is observed in animals classified under Reptilia. Scales are seen. Most of the reptilians have three chambered heart but crocodile has four-chambered heart. 4. Aves: These animals are evolved for flight. The body is covered with feathers. Wings are modified from fore-limbs. Animals are warm blooded. Possesses 4 chambered heart. Bones are hollow (pneumatic); which assists in flying. This class comprises of all birds.5. Mammalia: Hair covers the body. Sweat and sebaceous glands are observed. Mammary glands are present in females and are used for nourishing the young ones. Most of the animals of this class are viviparous. Some of the mammals lay eggs and are called as oviparous.

Chapter 7 : Diversity in Living Organisms