An Overview of Ncert Books Class 11 Biology Chapter 1 Free Download
FAQs on Ncert Books Class 11 Biology Chapter 1 Free Download
1. What are the key rules of Binomial Nomenclature that are frequently asked in the Class 11 exam for 2-3 marks?
For a 2 or 3-mark question on Binomial Nomenclature, you are expected to list the universally accepted rules. The most important ones for the 2025-26 CBSE exam are:
Biological names are generally in Latin and written in italics. When handwritten, both the generic name and specific epithet are underlined separately.
The first word in a biological name represents the genus and starts with a capital letter, while the second word denotes the specific epithet and starts with a small letter.
The name of the author appears after the specific epithet, at the end of the biological name, and is written in an abbreviated form, e.g., Mangifera indica Linn.
2. How should a student structure an answer for a 5-mark question on 'taxonomic aids' from The Living World?
To score full marks on a 5-mark question about taxonomic aids, your answer should be well-structured and comprehensive. A good approach is to:
Start with a brief introduction explaining the purpose of taxonomic aids – they help in the correct classification and identification of organisms.
Describe at least four to five different aids. For each aid (e.g., Herbarium, Botanical Garden, Museum, Zoological Park, Key), explain its definition, purpose, and the procedure involved.
For example, when describing a Herbarium, mention the collection, drying, pressing of specimens, and the information contained on the herbarium sheet. For a Museum, mention the preservation of specimens in jars with preservative solutions.
Conclude by summarising their collective importance in systematic studies.
3. Which topics from 'The Living World' are most important for MCQs and 1-mark questions?
For Multiple Choice Questions (MCQs) and Very Short Answer (VSA) questions from this chapter, you should focus on definitions and specific facts. Important areas include:
The full form of ICBN (International Code for Botanical Nomenclature) and ICZN (International Code of Zoological Nomenclature).
Definitions of core terms like taxonomy, systematics, and taxon.
The correct hierarchical order of taxonomic categories (Kingdom to Species).
The basic unit of classification (Species).
The purpose of a taxonomic key (identification based on contrasting characters).
4. While growth and reproduction are characteristics of living organisms, why are they not considered defining properties? This is a frequent HOTS question.
This is a critical concept tested in exams. Growth and reproduction are not considered defining properties of life because they have exceptions:
Growth: Non-living objects can also exhibit extrinsic growth, like the accumulation of material on the surface of mountains or boulders. In contrast, living beings show intrinsic growth (from inside). Because growth is not exclusive to living things, it is not a defining property.
Reproduction: Not all living organisms can reproduce. For example, sterile worker bees, mules, and infertile human couples are living but do not reproduce. Since there are living organisms that cannot reproduce, it cannot be an all-encompassing defining characteristic.
Metabolism, cellular organisation, and consciousness are considered defining properties as they have no exceptions in the living world.
5. How does a taxonomic 'key' differ from other aids like herbaria or museums in its function and importance?
This is an important comparative question. The primary difference lies in their function:
Function: A taxonomic key is an analytical tool used for the identification of unknown organisms. It works by presenting a series of contrasting, paired statements (couplets), requiring the user to make a choice that leads to further choices until the organism is identified. In contrast, herbaria and museums are repositories. They store and preserve actual specimens for future reference and study.
Importance: The unique importance of a key is that it provides a systematic and scientific method for identification. Herbaria and museums are crucial for verifying identifications and serving as a permanent record of an area's flora and fauna.
6. What is the difference between taxonomy and systematics, and which is considered a broader field for exam purposes?
For the CBSE Class 11 exam, understanding the distinction is crucial.
Taxonomy is the science of classification, which includes the processes of characterisation, identification, nomenclature, and classification of organisms into different taxa.
Systematics is a broader field. It includes taxonomy but also focuses on the evolutionary relationships (phylogeny) between organisms. It aims to understand the diversity of life in the context of evolution.
Therefore, systematics is the broader field as it integrates evolutionary history with classification. An important question might ask you to justify this relationship.
7. Why is it important for a student to know the correct ascending or descending order of the taxonomic hierarchy?
Knowing the correct taxonomic hierarchy (Kingdom, Phylum/Division, Class, Order, Family, Genus, Species) is fundamental and frequently tested. Its importance is:
Marks in Exams: Direct questions asking to arrange the taxa in the correct sequence are common for 1-2 marks.
Conceptual Clarity: It demonstrates your understanding that classification is not random but structured. As you move from species to kingdom (ascending order), the number of common characteristics decreases, while the number of organisms increases. This concept is often a part of higher-mark questions.
Foundation for other Chapters: This hierarchy is the framework used in subsequent chapters like Biological Classification, Plant Kingdom, and Animal Kingdom.
8. From an exam perspective, what is the significance of giving scientific names like Mangifera indica over common names like 'mango'?
This question tests your understanding of why a standardised naming system is necessary. The key points to include in your answer are:
Universality: A scientific name is universal and understood across the globe, irrespective of language. A common name like 'mango' varies from region to region and language to language, causing confusion.
Clarity and Precision: Each organism has only one valid scientific name, which prevents ambiguity. A single common name might refer to different organisms in different places.
Indicates Relationships: The generic name (e.g., Mangifera) helps in understanding its relationship with other species in the same genus, which is not evident from common names.
