Living and Non-Living: Characteristics, Habitat, Biodiversity and Conservation — REET Science Notes

What is the difference between living and non-living things?

Things that take in food, grow, respire, respond to a stimulus, excrete waste, and produce new organisms like themselves are called living things. Things that lack these characteristics are non-living — such as a stone, water, or a chair. The essence of the NCERT Class 6 treatment is that no single characteristic is enough on its own; in a living thing, all of these characteristics are found together.

This is exactly where the exam sets its trap. Clouds 'grow' and 'move', a motor vehicle 'consumes' fuel and 'releases' smoke, but none of these have cells or the ability to reproduce — so they are non-living. Conversely, plants do not move from place to place, yet they are living: their parts move (the leaves of the touch-me-not plant fold up when touched, sunflowers turn toward light), they respire day and night, and they produce new plants from seeds. In a dry seed, life processes slow down enormously; as soon as it gets water, air and the right temperature, it germinates — which is why a seed is considered living.

All living things are made of cells — the cell is the structural and functional unit of life. Organisms such as amoeba are unicellular, while humans and trees are multicellular. Death itself is a characteristic only of living things; a non-living object does not 'die', it only wears out or breaks.

Characteristics of living things — with examples

This table is based on the 'characteristics of living organisms' section of NCERT Class 6.[Source 1]

Habitat, adaptation and the components of an ecosystem

The surroundings in which an organism finds food, shelter and the conditions to reproduce is called its habitat — terrestrial (forest, desert, mountain) or aquatic (pond, river, sea). A habitat has two kinds of components: biotic components, meaning all the plants, animals and micro-organisms present; and abiotic components, meaning soil, water, air, temperature and light. Living and non-living surroundings together make up an ecosystem.

The special features of an organism that help it survive in its habitat are called adaptations. In the Rajasthan context, the camel is the best example: its long legs keep the body away from hot sand, it passes very little urine, and it can go without water for a long time. In cacti, leaves are reduced to spines to cut down transpiration, while the green, fleshy stem takes over food-making and water storage. A fish's streamlined body and gills are aquatic adaptations.

Biodiversity and conservation

The variety of organisms found in a region — their types, their relationships with each other, and their relationship with the environment — is called biodiversity. The plants of a region are called its flora, and the animals its fauna. A species found only in one particular region is called an endemic species of that region. Organisms whose numbers have fallen so low that they risk extinction are called endangered species; records of such organisms are maintained in the Red Data Book.

Deforestation — clearing trees for farming, cities, mining, or timber — is the single biggest cause of declining biodiversity. It leads to soil erosion, reduced rainfall, a falling groundwater table and increasing desertification. To counter this, the government has created protected areas: wildlife sanctuaries (protecting animals in their habitat), national parks (larger reserved areas protecting a whole ecosystem), and biosphere reserves (very large areas that conserve biodiversity alongside the traditional way of life of local communities). The NCERT Class 8 example is the Pachmarhi Biosphere Reserve (Madhya Pradesh), which includes Satpura National Park along with Bori and Pachmarhi wildlife sanctuaries.

The legal framework: the Wildlife (Protection) Act was passed in 1972; Project Tiger, to save the tiger, began in 1973; and the Biological Diversity Act was passed in 2002, under which the National Biodiversity Authority (NBA, Chennai) was established.

Protected areas important for REET

Sundarbans and Tal Chhapar were directly asked in REET 2024; the rest appeared as answer options.[Source 3]

Water: the most essential non-living resource

The existence of living things rests on abiotic components, and in Rajasthan the most pressing question is water. The main causes of the groundwater crisis are: overextraction of groundwater (drawing far more water than needed from tubewells), pollution of water sources, rising population and irrigation demand, deforestation, and neglect of traditional sources such as ponds and stepwells. Rainwater harvesting is not a cause of the crisis but its solution — this is exactly what REET 2024 tested.

Rajasthan's traditional water-harvesting structures — the taanka/kund (an underground collection of rainwater in a home or courtyard), baori (a stepwell), johad (a small earthen check-dam) and khadin (holding back water on a sloped field) — are very useful as local examples in the classroom.

How to teach this to children

REET 2024 questions (solved)

Practice questions

Frequently asked questions

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