The Living World Class 11 Notes PDF - Chapter 1 NCERT Biology 2027

Hello friends, Class 11 Biology Chapter 1 The Living World ke complete notes, definitions aur NEET 2027 ke important MCQ yahan milenge.NEET 2027: Chapter 1 The Living World - Short Notes* 🧬  

_Class 11 Biology | NCERT + PYQ  

### *1. What is Living?*  

- *Life*: Cannot be defined by single property. Living organisms show defining features.  

- *Defining Properties of Living Organisms* `NEET Gold`

**Property** **Living** **Non-Living** **Exception**

**Growth** Intrinsic, ↑ in mass & number Extrinsic, material added on surface Mountains, sand mounds grow

**Reproduction** Produces progeny No reproduction Mules, sterile worker bees, infertile humans can't reproduce

**Metabolism** Sum of all chemical reactions Absent Cell-free systems show metabolism

**Cellular Organization** Made of cells No cellular org -

**Consciousness** Respond to stimuli No response Plants respond to light, water

*NEET Trap*: Growth, reproduction are NOT defining properties. *Metabolism + Cellular organization + Consciousness = Defining features*.  

### *2. Diversity in Living World*  

- *Biodiversity*: 1.7-1.8 million species known. 8.7 million estimated.  

- *Nomenclature*: Naming of organisms.  

    1. *Vernacular Names*: Local names. Problem = Different names in different areas.  

    2. *Scientific Names*: Given by ICBN/ICZN. Universal.  

- *Binomial Nomenclature*: By Carolus Linnaeus.  

    1. *Rules*:  

          - 2 components = Generic name + Specific epithet. Ex: _Mangifera indica_.  

          - Latin, italicized when printed, underlined separately when handwritten.  

          - Generic name starts with capital, species with small letter.  

          - Author name after species in abbreviated form. Ex: _Mangifera indica_ Linn.  

    2. *NEET Gold*: _Homo sapiens_ = Human. _Musca domestica_ = Housefly. _Triticum aestivum_ = Wheat.  

### *3. Taxonomic Categories*  

*Taxonomy*: Characterisation, Identification, Classification, Nomenclature.  

*Systematics*: Taxonomy + Evolutionary relationships. Term by Linnaeus.  

*Taxonomic Hierarchy* `Ratta Maar Lo Sequence`

**Category** **Suffix-Plant** **Suffix-Animal** **Example: Human** **Example: Mango**

**Kingdom** - - Animalia Plantae

**Phylum/Division** -phyta - Chordata Angiospermae

**Class** -opsida, -ae - Mammalia Dicotyledonae

**Order** -ales - Primata Sapindales

**Family** -aceae -idae Hominidae Anacardiaceae

**Genus** - - *Homo* *Mangifera*

**Species** - - *sapiens* *indica*

*NEET Points*:  

1. *Higher the category, fewer the common characters*. Kingdom = least similarities. Species = max similarities.  

2. *Taxon*: Any rank in hierarchy. Ex: Mammalia is a taxon.  

3. *Solanaceae Family*: Potato, Tomato, Brinjal, Petunia. Floral formula same.  

### *4. Taxonomical Aids*  

_Tools for identification & classification_

**Aid** **Use** **NEET Point**

**Herbarium** Storehouse of dried, pressed plant specimens on sheets Quick referral. Label = Date, place, name, collector

**Botanical Gardens** Living plant collection for identification Kew = England, Indian Botanical Garden = Howrah

**Museum** Preserve plants & animals in preservative solutions Insects preserved in boxes after collecting, killing, pinning

**Zoological Parks** Wild animals in natural habitat under protection Learn behavior, food habits

**Key** Contrasting characters = Couplet. Each statement = Lead Taxonomic key for identification. Same key for all categories

**Flora** Actual account of habitat & distribution of plants -

**Manuals** Info for identification of names of species -

**Monographs** Info on any one taxon -

**Catalogues** List of publications -

### *5. Last 5 Year PYQ One Liners* `Most Important`  

1. *Metabolism* = Defining feature of living. Isolated metabolic reaction in vitro is living = NEET 2023.  

2. *ICBN* = International Code for Botanical Nomenclature. ICZN = Zoological.  

3. *Family Solanaceae* = Potato + Brinjal + Petunia = NEET 2022.  

4. *Growth cannot be defining property* because non-living objects also grow = NEET 2021.  

5. *Consciousness* = Most obvious & technically complicated feature of living = NEET 2020.  

6. *Systematics* = Includes identification, nomenclature, classification + evolutionary relationships.  

7. *Museum* = Animals preserved in jars in preservative solutions. Plants/animals may also be preserved as dry specimens.  

*Diagrams for NEET*: Taxonomic hierarchy with human & mango example

*Board me likhne ke liye*: `Ch-1 Living World` ya `NEET Binomial + Hierarchy`  

*1-2Q Pakka*: 1Q Defining property of living, 1Q Taxonomic hierarchy sequence/suffix.