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1


The Living World
1. Why are living organisms classified?
Solution:
Earth consists of millions of organisms, and we might be knowing the plants and animals that reside near us by their local names. These local names would vary from place to place, even within a country. This would lead to confusion in identifying and studying specific species. Hence to standardise the naming and studying of living organisms it should be called by a common name throughout the world. To achieve this, the organisms are named and classified according to their characters.
2. Why are the classification systems changing every now and then?
Solution:
Scientific study is ever progressing, and new species and organisms are added often. An early system of classification takes note of only habit and habitats of organisms. Gradually external morphology became toll for classification. After this, morphology and embryology are taken to consideration followed by phylogenetic relation, cytology of an organism. Modern-day uses biochemical techniques to classify the organisms based on their nucleic acid components.
3. What different criteria would you choose to classify people that you meet often?
Solution:
We classify the people that we often meet on the following attributes
  • Gender
  • Skin colour
  • Education
  • Profession
  • Hobbies
  • Nature
4. What do we learn from identification of individuals and populations?
Solution:
By identifying individuals and populations, we learn following things
  • Sex
  • Skin colour
  • Native place
  • Mother tongue
  • Food habit
  • Religion
  • Caste
5. Given below is the scientific name of Mango. Identify the correctly written name.
Mangifera Indica
Mangifera indica
Solution:
The answer is Mangifera indica. Here mangifera is its genus name, and indica is its species name which is always written in lowercase.
6. Define a taxon. Give some examples of taxa at different hierarchical levels.
Solution:
A taxon is a level of hierarchy in the system of classifying organisms.
Following are the hierarchical levels.
  • Kingdom
  • Phylum
  • Class
  • Order
  • Family
  • Genus
  • Species
7. Can you identify the correct sequence of taxonomical categories?
(a) Species Order Phylum Kingdom
(b) Genus Species Order Kingdom
(c) Species Genus Order Phylum
Solution:
Option a) and c) are the correct sequence of taxonomical categories
8. Try to collect all the currently accepted meanings for the word ‘species’. Discuss with your teacher the meaning of species in case of higher plants and animals on one hand, and bacteria on the other hand.
Solution:
A group of individual organisms with fundamental similarities are called species. It is the basic unit of classification. Species are also defined as the individuals that share the same gene pool.
Higher plants and animals: Criteria of reproductive isolation can be used to classify the species.
Bacteria: interbreeding and reproductive isolation cannot be used in case of bacteria here gene pool can be used to classify species.
9. Define and understand the following terms:
(i) Phylum (ii) Class (iii) Family (iv) Order (v) Genus
Solution:
i) Phylum is a taxonomical hierarchy below Kingdom and above Class. It is a taxon with one or more classes organisms with similar characters.
ii) Class is a taxonomical hierarchy higher than Order and lower than Phylum. Class includes related to orders of the organisms. Example: Presence of notochord in mammals.
iii) Family has a group of related genera with still less number of similarities as compared to genus and species. Example: Fox and dog belongs to the same family. It is a group of entities below Order and above Genus.
iv) Order is a taxon below higher than Family and lower than class. Order being a higher category is the assemblage of families which exhibit a few similar characters.
v) Genus comprises a group of related species which has more characters in common in comparison to species of other genera. Ex:Lion, tiger and leopard are classified under genus Panthera. It is above species and below Family.
10. How is a key helpful in the identification and classification of an organism?
Solution:
Key is a taxonomical aid used for identification of plants and animals based on the similarities and dissimilarities. It represents the choice between two opposite characters. It is helpful in identifying contrasting characters. They are a pair of two contrasting characters where selection of one character leads to the rejection of another character when species, family or genera is identified.
If an entitiy is not recorded already, attempst are made to firstc check and recheck its discovery before naming it. Hence, eveny entitiy can be classified whether it is unknown or known.
11. Illustrate the taxonomical hierarchy with suitable examples of a plant and an animal.
Solution:
Following table depicts the taxonomic hierarchy with Wheat as an example for plant and human as an example for animal.
Taxonomic categories
Wheat
Human
Kingdom
Plantae
Animalia
Phylum/Division
Angiospermae
Chordata
Class
Monocotylydonae
Mammalia
Order
Poales
Primata
Family
Poaceae
Homonidae
Genus
Triticum
Homo
Species
Triticum aestivum
Sapiens
NCERT Solutions for Class 11 Biology Chapter 1 – The Living World
The Living World is the 1st chapter categorized under Unit 1 – Diversity in the Living World. Biology is the science of life forms and living processes. This living world embraces an astonishing diversity of living entities and is vastly distinct in the boundless differences of characteristics they possess. The extraordinary habitats in which living entities are found can be extremely cold conditions or extremely hot conditions, deciduous forests, freshwater lakes, oceans, hot springs and so on.
Reproduction, growth, ability to sense environment mount an acceptable response as soon as we think of salient features of living entities. Few other features can be added, namely, ability to self-replicate, metabolism, self-organize, interacting, emergence also make to the list.
This chapter discusses the details of diversity in the living world.
List of subtopics covered in Chapter 1 – The Living World:
Number
Subtopic
1.1
What is Living?
1.2
Diversity in the living world
1.3
Taxonomic categories
1.4
Taxonomical Aids
NCERT Solutions for Class 11 Biology Chapter 1 – The Living World
In this chapter, we learn about different aspects of the living world. It has a rich variety of plants and animals even with what has been identified and described, whereas a larger number still remains undiscovered. Living entities vary in terms of colour, size, habitat, morphological and physiological features making us seek the defining characteristics of the living.
Biologists have evolved certain protocols to identify, name(nomenclature) and to classify organisms facilitating different kinds of study of diversity observed in organisms. This branch of knowledge that deals with various aspects of the classification of organisms is referred to as taxonomy.
Taxonomic studies and observance of different species of plants and animals is beneficial in a myriad of departments such as forestry, agriculture, industry, bio-resources and their diversity etc. On the basis of distinct differences and resemblances, every organism can be identified and assigned an appropriate scientific or biological name.
Key Features of NCERT Solutions for Class 11 Biology Chapter 1 – The Living World
  • NCERT Solutions for the chapter has been answered by extracting the most important and relevant information pertaining to the question
  • Use of tabular columns wherever necessary
  • Solutions are to the point and crisp
  • Use of pointers to learn quickly and remember easily
  • Solutions have been designed in such a way so as to fetch optimum marks
Frequently Asked Questions on Living World
Why are the classification systems changing every now and then?
Scientific study is ever progressing, and new species and organisms are added often. An early system of classification takes note of only habit and habitats of organisms. Gradually external morphology became toll for classification. After this, morphology and embryology are taken to consideration followed by phylogenetic relation, cytology of an organism. Modern-day uses biochemical techniques to classify the organisms based on their nucleic acid components.
Why are living organisms classified?
Earth consists of millions of organisms, and we might be knowing the plants and animals that reside near us by their local names. These local names would vary from place to place, even within a country. This would lead to confusion in identifying and studying specific species. Hence to standardise the naming and studying of living organisms it should be called by a common name throughout the world. To achieve this, the organisms are named and classified according to their characters.
What do we learn from identification of individuals and populations?
By identifying individuals and populations, we learn following things
  • Sex
  • Skin colour
  • Native place
  • Mother tongue
  • Food habit
  • Religion
  • Caste
Define a taxon?
A taxon is a level of hierarchy in the system of classifying organisms.
What different criteria would you choose to classify people that you meet often?
We classify the people that we often meet on the following attributes
  • Gender
  • Skin colour
  • Education
  • Profession
  • Hobbies
  • Nature


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