Living and Non-living

Overview

Living and Non-living is a foundational topic in the Science section of JKTET Paper II, forming the basis for understanding biology and environmental science. This topic tests your ability to distinguish between living organisms and non-living matter based on observable characteristics, and to understand how scientists classify the diversity of life on Earth.

For the exam, you must be clear on the defining characteristics that separate living things from non-living objects, understand borderline cases (like viruses), and know the hierarchy of biological classification. Questions typically ask you to identify characteristics, classify organisms into kingdoms, or apply these concepts to teaching scenarios in upper primary classrooms. Mastery here builds the conceptual foundation for topics on human body systems, plant life, and ecosystems.

Key Concepts

• **Living things** are organisms that exhibit all life processes — they are born, grow, respond to stimuli, reproduce, and eventually die. Non-living things lack these processes.

• **Seven characteristics of life** (MRS GREN or similar mnemonics) — Movement, Respiration, Sensitivity, Growth, Reproduction, Excretion, and Nutrition. All living organisms show all seven; non-living things show none or only some passively.

• **Growth in living things** is intrinsic (from within, by cell division) whereas non-living things like crystals or rivers grow by external addition of matter.

• **Viruses are borderline cases** — they show characteristics of life only inside a host cell. Outside, they behave like non-living particles. For exam purposes, viruses are often called "connecting link" between living and non-living.

• **Classification** is the systematic arrangement of organisms into groups based on similarities and differences. It helps in identification, studying relationships, and understanding evolution.

• **Five-Kingdom Classification** (Whittaker, 1969) divides all organisms into Monera, Protista, Fungi, Plantae, and Animalia based on cell structure, body organisation, and mode of nutrition.

• **Taxonomic hierarchy** from broadest to most specific: Kingdom → Phylum (Division for plants) → Class → Order → Family → Genus → Species. Species is the basic unit of classification.

• **Binomial nomenclature** (Linnaeus) gives every organism a two-part scientific name — Genus name + species name (e.g., Homo sapiens, Panthera tigris).

Formulas / Key Facts

| Characteristic | Living Things | Non-living Things | |----------------|---------------|-------------------| | Cellular structure | Made of cells | Not made of cells | | Growth | Internal (cell division) | External addition | | Reproduction | Produce offspring | Cannot reproduce | | Respiration | Exchange gases, release energy | No respiration | | Nutrition | Obtain and use food | No nutrition | | Excretion | Remove metabolic waste | No excretion | | Response to stimuli | React to environment | No response | | Movement | Self-initiated movement | Move only by external force | | Definite lifespan | Born, grow, die | No lifespan |

**Five Kingdoms at a glance:**

1. **Monera** — Prokaryotic, unicellular (bacteria, cyanobacteria) 2. **Protista** — Eukaryotic, mostly unicellular (amoeba, paramecium, euglena) 3. **Fungi** — Eukaryotic, heterotrophic by absorption, cell wall of chitin (mushroom, yeast, mould) 4. **Plantae** — Eukaryotic, multicellular, autotrophic (photosynthesis), cell wall of cellulose 5. **Animalia** — Eukaryotic, multicellular, heterotrophic, no cell wall

**Taxonomic hierarchy mnemonic:** King Philip Came Over For Good Soup (Kingdom, Phylum, Class, Order, Family, Genus, Species)

Worked Examples

**Example 1: Identifying living vs non-living**

*Question:* A student observes that a river "grows" during monsoon and "moves" constantly. Is a river living or non-living? Justify.

*Solution:*

• Step 1: Check if the river shows ALL characteristics of life.
• Step 2: River grows — but by external addition of rainwater, not by cell division.
• Step 3: River moves — but due to gravity, not self-initiated biological movement.
• Step 4: River does not respire, reproduce, or respond to stimuli biologically.
• **Conclusion:** River is non-living. Showing one or two characteristics due to physical forces does not make something living.

**Example 2: Classifying an organism**

*Question:* Mushroom grows on dead logs, has a cell wall, and absorbs nutrients from decaying matter. Which kingdom does it belong to?

*Solution:*

• Step 1: Has cell wall — could be Plantae or Fungi.
• Step 2: Absorbs nutrients (heterotrophic) — not autotrophic like plants.
• Step 3: Grows on dead matter — saprophytic nutrition.
• **Conclusion:** Mushroom belongs to Kingdom Fungi.

**Example 3: Writing scientific name**

*Question:* Write the scientific name of the Hangul (Kashmir stag) correctly.

*Solution:*

• Scientific name: Cervus hanglu (sometimes Cervus elaphus hanglu)
• Rules: Genus name capitalised (Cervus), species name in lowercase (hanglu), entire name italicised or underlined when handwritten.
• **Answer:** *Cervus hanglu*

Common Mistakes

• **Confusing physical change with life processes** → Students think fire is living because it "grows" and "moves." Correct: Fire lacks cellular structure, reproduction, and nutrition — it is a chemical reaction, not a living thing.

• **Thinking all things with cells are living** → Dead leaves have cells but are non-living. Correct: Living things are those currently performing life processes; dead matter once was living but no longer is.

• **Placing fungi in Plantae** → Students assume anything that grows on soil is a plant. Correct: Fungi are heterotrophic and have chitin cell walls; plants are autotrophic with cellulose walls.

• **Writing scientific names incorrectly** → Writing both genus and species in capitals or without italics. Correct: Only genus is capitalised; species is lowercase; both are italicised or underlined.

• **Forgetting viruses are acellular** → Treating viruses as part of Monera. Correct: Viruses are not placed in any kingdom because they are not truly cellular and show life only inside hosts.

Quick Reference

• Living things show all seven life processes: Movement, Respiration, Sensitivity, Growth, Reproduction, Excretion, Nutrition (MRS GREN).

• Non-living things may show some characteristics (fire moves, crystals grow) but not through biological processes.

• Five Kingdoms: Monera (prokaryotes), Protista (unicellular eukaryotes), Fungi, Plantae, Animalia.

• Taxonomic hierarchy: Kingdom → Phylum → Class → Order → Family → Genus → Species.

• Binomial nomenclature: Genus (capital) + species (lowercase), both italicised — e.g., *Panthera leo*.

• Viruses are neither living nor non-living — they are obligate parasites showing life only inside host cells.