Chapter 9 — The Living Organisms And Their Surroundings

What are living and non-living things?

Living things are organisms that show the characteristics of life: they are made of cells, take food, respire to release energy, grow, move (or show movement of parts), reproduce, respond to stimuli, and remove waste (excretion). Non-living things do not show these life processes on their own.

Key life processes (short):

• Nutrition: obtaining and using food (plants make food by photosynthesis; animals eat food).
• Respiration: releasing energy from food (chemical reactions inside cells).
• Growth: increase in size or number of cells over time.
• Movement: whole-body movement (animals) or movement of parts (plants bending towards light).
• Reproduction: producing new organisms of the same kind.
• Sensitivity/Response: reacting to changes in the environment (e.g., plants bending toward light; animals fleeing danger).
• Excretion: removal of metabolic wastes (e.g., sweat, urine, leaf fall).

Differences (summary):

• Living things have cellular organization; non-living do not.
• Living things perform life processes; non-living objects do not perform them by themselves.
• Living things can grow and reproduce (or have the potential to); non-living things cannot.

Special/important cases:

• Dead things: were once living but no longer show life processes (e.g., a dried leaf, dead animal). Dead things are not the same as never-living things.
• Dormant forms: seeds, spores, or some organisms can be dormant (appear inactive) but are still alive because they can resume life processes under favorable conditions.
• Borderline cases: viruses are debated—outside a host they are inert like non-living things but inside a host they replicate, so they sit on the boundary between living and non-living.

How to test if something is living (simple checks): look for growth, reproduction, response to stimuli, movement of parts, and metabolic activity (e.g., does it need food/produce waste?).

Why this matters: Understanding living vs non-living helps classify objects in nature, care for living organisms (plants, pets), and solve everyday problems (e.g., preserving food, identifying hazards).

What are living organisms? Living organisms are plants, animals, fungi, bacteria and other forms of life that show certain basic life processes. These processes distinguish living things from non-living things.

• Cellular organization: Every living organism is made of one or more cells. Unicellular organisms (like Amoeba) are single-celled; multicellular organisms (like humans and trees) have many cells organised into tissues and organs.
• Nutrition: Living things take food to get energy and materials for growth and repair. Plants are mostly autotrophs (make food by photosynthesis); animals are heterotrophs (eat plants or other animals).
• Respiration: Organisms obtain energy from the breakdown of food. Aerobic respiration uses oxygen and releases carbon dioxide and energy; some organisms use anaerobic respiration (no oxygen).
• Growth: Living organisms grow — their size, mass or number of cells increases with time. Growth can be measured (for example, increase in height of a plant or weight of an animal).
• Movement: Many living things move at least some part of their body. Animals move from place to place; plants show movement too (e.g., leaves or stems bending toward light, roots growing into soil). Movement can be external (walking, swimming) or internal (transport of nutrients and fluids).
• Sensitivity / Response to stimuli: Living organisms respond to changes in their environment. For example, pupils of eyes contract in bright light, plants bend toward light (phototropism), and animals withdraw from pain.
• Excretion: Removal of waste products produced during metabolism (e.g., carbon dioxide, urine) is necessary to maintain internal balance. Plants and animals have different excretory structures.
• Reproduction: Living organisms produce new individuals of the same kind. Reproduction may be sexual (two parents, variation) or asexual (one parent, identical offspring) — e.g., binary fission in bacteria, seeds in flowering plants, eggs in animals.
• Adaptation: Organisms have features that help them survive in their environment — camels store fat in humps and have long eyelashes for desert life; cactus stores water and has spines to reduce water loss.

Simple ways to test if something is living (useful for class activities): check for at least one internal process such as growth, reproduction, nutrition, respiration, movement, response to stimuli or excretion. Note: some living things (like dry seeds or dormant bacteria) may appear inactive but are still living.

Exceptions & notes: Viruses are not placed among living organisms in this class because they cannot carry out life processes by themselves outside a host cell. Also, a dead organism may still show movement (e.g., a thrown dead fish) but it no longer carries out life processes.

Key classroom connections: Use local examples (houseplant growth, breathing exercises, yeast dough rising) to demonstrate these characteristics. Simple experiments: germinate seeds to show growth and nutrition; yeast in sugar solution to show respiration (CO2 bubbles).

Definition: The surroundings of a living organism include everything that affects its life — both living (plants, animals, microbes) and non-living (light, water, soil, temperature). A habitat is the natural place where an organism lives and obtains food, shelter and mates.

Components of surroundings

• Abiotic factors (non-living): sunlight, water, air, soil, temperature, minerals, humidity, wind.
• Biotic factors (living): plants, animals, microbes, dead organic matter and the interactions among them (predation, competition, symbiosis).

Features of a habitat

• Provides food, shelter and mates.
• Has specific abiotic conditions (e.g., temperature, moisture) that suit particular organisms.
• Can change with seasons or human activity, causing organisms to adapt, move, or die out.

Types of habitats (brief)

• Terrestrial — forests, deserts, grasslands.
• Aquatic — freshwater (ponds, rivers, lakes) and marine (seas, oceans).
• Arboreal — lives in trees (many birds, monkeys).
• Underground — burrows and soil (earthworms, moles).

Adaptations to habitat

Organisms show structural, behavioral and physiological adaptations that help them survive in their habitat.

• Structural: thick fur in polar animals, long roots in desert plants.
• Behavioral: migration of birds, nocturnal activity of desert animals.
• Physiological: ability to conserve water (cacti), antifreeze proteins in some cold-water fish.

Interdependence and food chains

Organisms are interdependent: plants (producers) make food from sunlight; herbivores (primary consumers) eat plants; carnivores (secondary/tertiary consumers) eat other animals; decomposers (bacteria, fungi) break down dead matter and return nutrients to the soil. Example simple food chain: grass → grasshopper → frog → snake.

Changes in surroundings

Seasonal changes, natural disasters and human activities (deforestation, pollution, urbanisation) alter habitats. Organisms respond by adapting, migrating, reducing numbers, or becoming extinct. Conservation (protected areas, sustainable use, pollution control) helps protect habitats.

Classroom activity ideas

• Observe a microhabitat (under a rock, leaf litter, pond edge) and list biotic & abiotic factors.
• Draw a food chain from observed organisms and identify producer, consumer, decomposer.

What is a habitat?

A habitat is the place where a living organism (plant, animal, fungus or microbe) lives and obtains food, water, shelter and space to survive and reproduce. A habitat provides the specific physical and biological conditions that a species needs.

Factors that define a habitat

• Availability of water
• Temperature and climate
• Type of soil or water (salinity, pH)
• Light and oxygen availability
• Shelter and space
• Food supply and presence of other organisms

Main types of habitats

1. Terrestrial habitats

These are land habitats. Common subtypes:

• Forest: Many trees, layered vegetation and rich biodiversity (e.g., tigers, monkeys, ferns).
• Grassland: Large open areas with grasses (e.g., deer, bison, grasses).
• Desert: Very low rainfall, sparse vegetation (e.g., camels, cacti, lizards).
• Mountain: High altitude, low temperature, steep slopes (e.g., mountain goats, alpine plants).

2. Aquatic habitats

Habitats in water. Two major types:

• Freshwater: Ponds, lakes, rivers, streams. (e.g., frogs, freshwater fish, water plants like lotus).
• Marine (saltwater): Oceans and seas, including tidal zones and coral reefs. (e.g., fish, corals, whales).

3. Arboreal and Aerial habitats

Arboreal: Lives in trees (e.g., squirrels, many birds, tree frogs). Aerial: Organisms that spend most of their life in flight (e.g., many birds, some insects like swifts and butterflies).

4. Subterranean and Microhabitats

Subterranean: below ground (e.g., earthworms, mole). Microhabitats: very small specialized places such as under a rock, inside a rotting log, the bark of a tree or a puddle—each supports specific life.

5. Transitional habitats

Areas where two habitats meet, for example estuaries (where river meets sea), mangroves, and wetlands. These are rich in biodiversity and often highly productive.

Adaptations to habitats (brief)

• Desert: Water storage, nocturnal behaviour, reduced leaves (plants) — e.g., camel has humps; cactus stores water.
• Aquatic: Gills, streamlined bodies, fins (fish); buoyant seeds or floating leaves (water plants).
• Forest/Arboreal: Strong limbs, grasping feet, camouflage (many birds and monkeys).
• Polar: Thick blubber or fur, white coloration for camouflage (polar bear, penguin).

Importance of habitats

• Support biodiversity and ecological balance.
• Provide ecosystem services (clean water, air, pollination, food).
• Need protection — habitat loss leads to species decline and extinction.

Note for students: When you observe organisms, ask: Where do they get water? Where are they sheltering? How is their body suited to that place? That helps identify the habitat and adaptations.

What are adaptations? Adaptations are special features — structural, behavioural or physiological — that help organisms survive and reproduce in their surroundings. Adaptations develop over many generations by natural selection and allow plants and animals to get food, protect themselves, keep their body temperature, and save water.

Types of adaptations

• Structural (Morphological) adaptations: Physical features of body or parts. Examples: thick fur, long beaks, webbed feet, deep roots, waxy leaves.
• Behavioural adaptations: Actions or habits that help survival. Examples: migration, hibernation, nocturnal activity, hunting in groups.
• Physiological (Functional) adaptations: Internal body processes that increase survival. Examples: production of venom, concentration of urine to save water, producing sweat or fat for insulation.

Adaptations in different habitats

• Desert (xeric) adaptations: Plants: reduced or no leaves, thick stems for water storage (cactus), waxy surface. Animals: camels store fat in humps, have long eyelashes and nostrils that close; many are nocturnal to avoid daytime heat.
• Aquatic (hydrophyte) adaptations: Plants: large flat leaves, aerenchyma (air spaces) to float (water lily). Animals: fish have gills and streamlined bodies; ducks have webbed feet for swimming.
• Cold region adaptations: Animals: thick fur or blubber (polar bear, penguin) to retain heat; white fur or feathers for camouflage in snow.
• Forest/jungle adaptations: Many animals are arboreal (live in trees) with grasping limbs; leaves may be large and drip-shaped to shed water (drip tips).

Mimicry and camouflage

Camouflage helps organisms blend with surroundings (stick insects, leaf insects, snow hare). Mimicry is when one species looks like another (some harmless butterflies look like toxic ones to avoid predators).

Short-term adjustments vs inherited adaptations

Acclimatisation (short-term) is when an organism temporarily adjusts to a change (e.g., humans sweating in heat). Adaptation (long-term) is an inherited trait shaped over many generations (e.g., camels evolved humps).

How adaptations help

• Save water (waxy cuticle, reduced leaves, concentrated urine)
• Obtain food (specialised beaks, carnivorous plant traps)
• Avoid predators (camouflage, living in groups, toxic chemicals)
• Regulate body temperature (fat, fur, behavioural changes like basking)

Summary: Adaptations are specific features or behaviours that increase the chances of survival in particular surroundings. Observing habitats and comparing plant and animal features shows clear links between form, function and environment.

What it means
Food and shelter relationships describe how living organisms depend on other organisms and their surroundings to obtain food and a place to live (shelter). These relationships show interdependence: organisms need food for energy and shelter for protection, breeding and caring for young.

Key components

• Producers – Green plants that make their own food by photosynthesis and form the base of food chains.
• Consumers – Animals that eat plants or other animals. They are classified as herbivores (plant-eaters), carnivores (meat-eaters) and omnivores (eat both).
• Decomposers – Microorganisms (bacteria, fungi) that break down dead plants and animals to release nutrients back into the soil.
• Habitat and shelter – The place where an organism lives (habitat) and the specific structure it uses for safety or raising young (shelter), for example nests, burrows, stems, tree holes, caves, or human houses.

How food and shelter relationships work
1. Food chains and food webs show who eats whom. Energy flows from producers to consumers and then to decomposers.
2. Shelter provides protection from predators, harsh weather, and a safe site for raising offspring. Often the same plant or place can provide both food and shelter (e.g., a fruit tree gives fruits and nesting sites).

Adaptations
Organisms develop structural and behavioral features to get food and build shelter: beaks for different diets (e.g., nectar-feeding birds), camouflaged fur for hiding, burrowing behaviour for protection, or building nests/hives. These adaptations help them survive in their habitat.

Interdependence and balance
Removal or change of food sources or shelters (for example, cutting trees) affects many organisms: animals may move, reduce in number, or die out. Decomposers recycle nutrients so plants can grow again, keeping the cycle going.

Interdependence
All living organisms depend on other organisms and on the non-living environment for food, shelter and other needs. Plants, animals and microorganisms interact in many ways — by eating (feeding), by providing shelter, and by affecting the environment. These interactions form an ecological network in which every organism has a role.

Producers, Consumers and Decomposers

• Producers (autotrophs) are organisms that make their own food using sunlight (photosynthesis). Example: green plants, algae.
• Consumers (heterotrophs) obtain food by eating other organisms. They are of three main types: herbivores (eat plants), carnivores (eat animals), and omnivores (eat both).
• Decomposers (saprophytes) break down dead plants and animals and return nutrients to the soil. Example: bacteria, fungi.

Simple Food Chain
A food chain is a straight-line sequence that shows who eats whom. It starts with a producer and ends with a top consumer (or decomposer). Arrows (→) show the direction of energy flow: what is eaten becomes energy for the next organism. Example format: Plant → Herbivore → Carnivore → Decomposer.

Food Web
In nature, many food chains are connected. This network is called a food web. Food webs show that organisms may have multiple food sources and are connected to many other organisms — this increases stability of the ecosystem.

Energy Flow and Balance
Energy for almost all ecosystems starts from the Sun, captured by producers. Energy flows one-way through the system (Sun → producers → consumers → decomposers) and decreases at each step because organisms use energy for life processes. Decomposers recycle nutrients back into the environment so producers can use them again.

Importance
Interdependence keeps ecosystems balanced: if one species is removed or its population changes greatly, many other species are affected. Humans can disturb these relationships by overhunting, pollution, and destroying habitats.

How to make a simple food chain

1. Identify a producer (usually a green plant).
2. Find a herbivore that eats that plant.
3. Find a carnivore that eats that herbivore.
4. Show the flow with arrows: Producer → Herbivore → Carnivore → (Decomposer).

Population: A population is a group of individuals of the same species living in a particular area at the same time. Example: all mango trees in a school garden, all sparrows in a courtyard.

Community: A community consists of all the different populations of plants, animals and microorganisms living and interacting in a particular area. Example: the plants, insects, birds and microbes in a pond form a pond community.

Key features of a population (simple):

• Size (N) — number of individuals.
• Density — how many individuals per unit area or volume.
• Distribution — how individuals are spaced (clumped, uniform, random).
• Age structure — proportion of young and old; affects growth.

Factors that change population size: births (increase), deaths (decrease), immigration (individuals coming in), emigration (individuals leaving). Environmental limits such as food, space, predators and disease also affect population.

Interactions in a community (basic types):

• Competition — individuals or species compete for the same resource (e.g., light, water).
• Predation — one organism (predator) eats another (prey).
• Mutualism — both species benefit (e.g., bees and flowering plants).
• Commensalism — one benefits, the other is neither harmed nor helped (e.g., small plants growing on tree bark).

Habitat and niche (simple): A habitat is the place where an organism lives (a pond, a tree). A niche is the role or job of the organism in the community (what it eats, where it lives, how it behaves).

Carrying capacity (K): The maximum population size that the environment can support for a species given available resources.

These ideas help us understand how living things are distributed, how populations change, and how different species depend on one another in nature.

What are microorganisms?
Microorganisms (microbes) are tiny living organisms that cannot be seen with the naked eye. They include bacteria, fungi (moulds and yeasts), protozoa, algae and viruses. They are everywhere — in soil, water, air, on plants, animals and in our bodies.

Types (short):

• Bacteria: single-celled, some cause disease, many are useful (e.g., nitrogen-fixers, probiotics).
• Fungi: moulds and yeasts. Moulds cause bread rot; yeasts are used in baking and fermentation.
• Protozoa: single-celled animals found in water and soil.
• Algae: simple photosynthetic organisms in water.
• Viruses: much smaller than cells; cause many diseases and need a host to reproduce.

Where do they live?
Microorganisms live in a wide range of surroundings: warm or cold, damp or dry, acidic or basic places — but each species has preferred conditions. They are found in pond water, soil, decaying material, on our skin and inside our stomachs.

Conditions affecting growth (factors that help or limit microbes):

• Moisture: Most microbes grow well in moist conditions.
• Food: Organic matter (sugars, proteins, fats) supports growth.
• Temperature: Each species has an optimum temperature; many harmful bacteria grow well at body temperature (~37°C), while others prefer cold or hot conditions.
• Oxygen: Some need oxygen (aerobic), some cannot tolerate it (anaerobic).
• pH, light, and salt concentration: Also control where microbes survive.

Roles of microorganisms:

• Useful roles: decomposition (recycling nutrients), food production (yogurt, cheese, bread), fermentation (alcohol), nitrogen fixation in soil, sewage treatment, medicines (antibiotics).
• Harmful roles: spoilage of food, diseases in plants, animals and humans, production of toxins.

How their surroundings influence them: Changes in temperature, moisture, availability of food and oxygen determine whether microbes multiply, remain inactive or die. For example, moist warm food left at room temperature allows bacteria to multiply rapidly and spoil the food.

Control and safety measures:

• Cleaning, washing hands and utensils, boiling or heating food (pasteurization), refrigeration, drying, salting, pickling and using preservatives reduce or stop microbial growth.
• Sterilization and use of disinfectants kill microbes on surfaces and instruments.
• Antibiotics treat bacterial infections (used under medical guidance).

Simple classroom experiment idea (safety note: adult supervision): Place pieces of bread in two clear, labelled jars — one kept dry and sealed, the other slightly moist and sealed. Keep both in a warm place and observe for mould growth over several days. You will see that the moist bread develops mould faster. Always dispose of mouldy samples carefully.

Summary: Microorganisms are tiny but essential components of ecosystems. Their surroundings — moisture, food, temperature, oxygen and other factors — determine whether they thrive or perish. They can be both helpful and harmful; understanding their needs helps us use them productively and control their dangers.

What are environmental changes? Environmental changes are alterations in the surroundings in which organisms live. These changes can be natural (seasonal changes, volcanic eruptions, floods) or caused by humans (deforestation, pollution, urbanization, climate change).

Key factors (abiotic and biotic):

• Abiotic: temperature, light, water, soil, air, humidity, pollutants.
• Biotic: availability of food, predators, competitors, diseases.

How changes affect living organisms

• Behavioral responses (short-term): Movement to a new place (migration), becoming inactive (hibernation), or changing feeding time. Example: Birds migrate to warmer regions in winter.
• Physiological responses (short- to medium-term): Changes inside the body — for example, producing antifreeze-like substances, shedding leaves to reduce water loss, or adjusting metabolic rate.
• Structural or evolutionary adaptations (long-term): Over many generations species may evolve traits suitable for new conditions (thicker fur in colder climates, deeper roots in dry areas).
• Population effects: If conditions become unfavorable, birth rates drop and death rates rise — populations may decrease, become locally extinct, or sometimes increase if a change favors a species.
• Community and ecosystem effects: Food chains/webs can be disrupted (if one species declines many others are affected), leading to reduced biodiversity and altered ecosystem functioning.

Human-caused changes and their impacts

• Pollution (air, water, soil): can poison organisms, cause diseases, or lead to reduced reproduction (e.g., fish kills from chemical spills).
• Deforestation and habitat destruction: loss of homes for wildlife, soil erosion, fewer plants to make oxygen and hold soil.
• Climate change (global warming): altered rainfall and temperature patterns, coral bleaching, shifts in breeding and flowering times.

Examples of organism responses: Migration (birds and whales), hibernation (bears, some frogs), dormancy/seed resting (many plants), behavioral change (urban animals becoming nocturnal), adaptation (camouflage, changed leaf structure).

How we can reduce harmful effects

• Planting trees and restoring habitats.
• Reducing pollution by proper waste management and cleaner fuels.
• Creating protected areas and wildlife corridors.
• Using water and other resources sustainably.

What it means
Conservation and care for surroundings means protecting, maintaining and improving the natural and built environment around us — air, water, soil, plants, animals and public spaces — so that resources remain available and the environment is healthy for present and future generations.

Why it is important

• Maintains balance of ecosystems and protects biodiversity.
• Prevents pollution and health problems (cleaner air and water).
• Preserves resources (water, soil, forests) for future use.
• Improves quality of life and aesthetics of neighborhoods.

Main threats to surroundings

• Pollution: air, water, soil and noise.
• Deforestation and loss of green cover.
• Improper disposal of solid waste (littering, plastics).
• Overuse and wastage of water and energy.

Key principles and practical measures

• Reduce, Reuse, Recycle (3 R's): Buy less, reuse items (glass jars, cloth bags), segregate and send waste for recycling.
• Segregation of waste: Separate biodegradable (kitchen waste, leaves) and non-biodegradable (plastic, glass, metal) at source. Biodegradable goes to composting; non-biodegradable to recyclers.
• Composting: Convert kitchen and garden waste into compost (organic manure) to enrich soil instead of sending it to landfill.
• Saving water: Fix leaks, use buckets for bathing, reuse greywater for plants, practise rainwater harvesting.
• Saving energy: Switch off lights and fans when not needed, use energy-efficient bulbs, prefer natural light and ventilation, use public transport or cycle.
• Planting and protecting trees: Trees provide oxygen, shade, reduce soil erosion and support wildlife.
• Preventing pollution: Avoid burning waste, discourage single‑use plastics, properly dispose of hazardous waste (batteries, bulbs).
• Community action and awareness: Cleanliness drives, school projects, enforcing local rules, and educating neighbours.

Role of students and households

• Keep surroundings and school clean; use dustbins and do not litter.
• Start or join a gardening or composting project.
• Save water and electricity at home and encourage family members to do the same.
• Participate in tree plantation and awareness programs.

Biodegradable vs Non-biodegradable
Biodegradable materials (food waste, paper, leaves) break down naturally by decomposers (bacteria, fungi, worms). Non-biodegradable materials (plastic, glass, synthetic fabric) do not break down easily and accumulate, causing pollution.

Consequences of neglect
If we do not care for our surroundings we face polluted water and air, more disease, loss of plants and animals, scarcity of clean water and degraded soil.

Simple action plan

1. Segregate waste at home (wet / dry / hazardous).
2. Compost wet waste at home or community compost pit.
3. Use a cloth bag instead of plastic; carry a water bottle.
4. Report illegal dumping and join local clean-up drives.

Learning this topic helps students become responsible citizens who can protect the environment through small daily actions.