CBSE Quick Revision Notes CBSE Class-11 Biology CHAPTER-01 THE LIVING WORLD Life is a unique, complex organization of molecules that expresses itself through chemical reactions which lead to growth, development, responsiveness, adaptation and reproduction. The objects exhibiting growth, development, reproduction, respiration, responsiveness and other characteristics of life are designated as living beings. Unique features of living organism:- Growth- Living organisms grow in mass and number. A multicellular organism increases its mass by cell division. In plants growth continuous throughout life in their meristematic area but in animals, growth occurs to a certain age. Unicellular organisms also grow by cell division. Living organisms show internal growth due to addition of materials and formation of cells inside the body. Non living organism like mountains, boulders, crystals also grow but due to addition of similar materials to their outer surface. Reproduction- It is the formation

  CBSE Class 11 Biology NCERT Solutions Chapter 1 DIVERSITY IN THE LIVING WORLD 1. Why are living organisms classified? Ans.  A large variety of plants, animals, and microbes are found on earth. All these living organisms differ in size, shape, colour, habitat, and many other characteristics. As there are millions of living organisms on earth, studying each of them is impossible. Therefore, scientists have devised mechanisms to classify all living organisms. These methods of classification are based on rules and principles that allow identification, nomenclature, and finally classification of an organism. Therefore, the biological classification helps in revealing the relationship between various organisms. It also helps in making study of organisms easy and organized. 2.   Why are the classification systems changing every now and then? Ans.  Millions of plants, animals, and microorganisms are found on earth. Many of these have been identified by the scientists while many new species a

  CBSE TEST PAPER-01 CLASS - XI BIOLOGY (The Living World) General Instruction: All questions are compulsory. Question No. 1 to 3 carry one marks each. Question No. 4 to 6 carry two marks each. Question No. 7 and 8 carry three marks each. Question No. 9 carry five marks. 1. Name the three fields of systematics. 2. Give the two name system of organisms? 3. Write the correct order of sequence of taxonomical categories? 4. What are the advantages of giving scientific names of the organisms? 5. Give the role of botanical gardens? 6. Differentiate between species & taxon? 7. Name the guidelines for naming of organisms? 8. What is Biological classification? What is the need of classification? 9. What is Binomial system of nomenclature? Who proposed this system? Why is binomial nomenclature the most acceptable mode of naming organism? CBSE TEST PAPER-01 CLASS - XI BIOLOGY (The Living World) [ANSWERS] Ans. 1 Nomenclature, classification & taxonomy. Ans. 2 Binomial Nomenclature Ans. 3 S

  CBSE Quick Revision Notes CBSE Class-11 Biology CHAPTER-02 BIOLOGICAL CLASSIFICATION Biological classification is the scientific procedure of arranging organisms into groups and subgroups on the basis of their similarities and dissimilarities and placing the group in a hierarchy of categories. Importance of classification- It is not possible to study every organism. Study of one or two organism of a group gives sufficient information about the essential features of the group. It helps in identification of new organism. Classification helps in knowing the relationship amongst different groups of organisms. The organism of past cannot be studied without a proper system of classification. Classification Artificial system of classification Natural system of classification Phylogenetic system of classification Artificial system of classification - Only one or two morphological characters for grouping of organism is used. Flowering and non-flowering plants, enaima and anaima. Aristotle cla