The Living World - Exercise

Subject: Biology
Class: 11
Topic: The Living World

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Section A: Multiple Choice Questions (MCQs)

1. The number of species that are known and described range between: a) 1.5-1.6 million b) 1.7-1.8 million c) 1.9-2.0 million d) 2.1-2.2 million

2. ICBN stands for: a) International Code for Biological Nomenclature b) International Code for Botanical Nomenclature c) International Class for Biological Nomenclature d) International Class for Botanical Nomenclature

3. Binomial nomenclature was given by: a) Ernst Mayr b) Carolus Linnaeus c) Charles Darwin d) Lamarck

4. In Mangifera indica Linn., 'Linn.' indicates: a) Latin origin b) Linnaeus described it first c) Locality of the plant d) Type of species

5. The basic unit of classification is: a) Genus b) Species c) Order d) Kingdom

6. Which of the following represents the correct sequence of taxonomic categories in ascending order? a) Species → Genus → Family → Order → Class → Phylum → Kingdom b) Kingdom → Phylum → Class → Order → Family → Genus → Species c) Species → Genus → Order → Family → Class → Phylum → Kingdom d) Species → Genus → Family → Class → Order → Phylum → Kingdom

7. Taxonomy includes: a) Identification b) Nomenclature c) Classification d) All of these

8. Systematics takes into account: a) Morphological characters b) Evolutionary relationships c) Ecological information d) None of these

9. The scientific name of housefly is: a) Homo sapiens b) Mangifera indica c) Musca domestica d) Triticum aestivum

10. Which category includes related orders? a) Family b) Class c) Phylum d) Genus

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Section B: NCERT Textbook Exercises (Questions & Answers)

1. Why are living organisms classified? Answer: Living organisms are classified to make the study of millions of diverse life forms systematic, easy, and convenient. Classification helps in identifying similarities and differences among organisms and establishes relationships between different groups.

2. Why are the classification systems changing every now and then? Answer: Classification systems change because new organisms are constantly being discovered. Additionally, as our understanding of evolutionary relationships, genetic information, and internal structures improves with new technologies, we need to update the classification to reflect these scientific advancements.

3. What different criteria would you choose to classify people that you meet often? Answer: Criteria could include:

• Relationship (Family, friend, acquaintance, stranger)
• Profession (Student, teacher, doctor, engineer)
• Age group (Child, teenager, adult, elderly)
• Location/Origin (Local, from another city, from another country)
• Shared interests (Hobby-based)

4. What do we learn from identification of individuals and populations? Answer: Identification helps us learn about the specific characteristics, habitats, and behaviors of individuals and populations. It allows us to distinguish one species from another, understand its ecological role, and determine its evolutionary relationship with other organisms.

5. Given below is the scientific name of Mango. Identify the correctly written name.

• Mangifera Indica
• Mangifera indica Answer: The correctly written name is Mangifera indica. (The genus name starts with a capital letter, and the specific epithet starts with a small letter).

6. Define a taxon. Give some examples of taxa at different hierarchical levels. Answer: A taxon (plural: taxa) is a scientific term for any category or rank in the taxonomic hierarchy. Examples:

• Species: sapiens
• Genus: Panthera
• Family: Felidae
• Order: Carnivora
• Class: Mammalia
• Kingdom: Animalia

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 Answer: (c) Species → Genus → Order → Phylum is the correct sequence (though some levels are skipped, the relative order is correct).

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. Answer:

• In higher plants and animals, a species is generally defined as a group of organisms that can interbreed and produce fertile offspring.
• In bacteria, which reproduce asexually, species are often defined based on biochemical, physiological, and genetic similarities (DNA sequence similarity).

9. Define and understand the following terms: (i) Phylum (ii) Class (iii) Family (iv) Order (v) Genus Answer:

• Genus: A group of related species with more characters in common than species of other genera.
• Family: A group of related genera with fewer similarities than genus level.
• Order: An assemblage of families exhibiting a few similar characters.
• Class: Includes related orders.
• Phylum: Classes comprising animals with common features like a notochord.

10. Illustrate the taxonomical hierarchy with suitable examples of a plant and an animal. Answer:

• Animal (Man): Kingdom: Animalia → Phylum: Chordata → Class: Mammalia → Order: Primata → Family: Hominidae → Genus: Homo → Species: sapiens.
• Plant (Mango): Kingdom: Plantae → Division: Angiospermae → Class: Dicotyledonae → Order: Sapindales → Family: Anacardiaceae → Genus: Mangifera → Species: indica.

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Answer Key for MCQs

1. b 2. b 3. b 4. b 5. b 6. a 7. d 8. b 9. c 10. b