Quick Revision Notes & Formula Sheet

Class: 6th
Subject: Science
Chapter: The Living Organisms — Characteristics and Habitats
Board: MP Board (NCERT Curriculum)

1. Important Keywords & Definitions (महत्वपूर्ण परिभाषाएँ)

• Organism (सजीव): Any living being that has the properties of life (e.g., plants, animals, humans, microorganisms).
• Habitat (आवास): The surroundings or natural home where a plant or animal lives, grows, and reproduces. It provides food, water, air, and shelter.
• Biotic Components (जैविक घटक): The living things in a habitat (e.g., plants, animals, microorganisms).
• Abiotic Components (अजैविक घटक): The non-living things in a habitat (e.g., rocks, soil, air, water, sunlight, temperature).
• Adaptation (अनुकूलन): Specific features or certain habits that help a plant or animal live in its surroundings.
• Acclimatization (अक्लिमटाइजेशन / अल्पकालिक अनुकूलन): Small changes a single organism makes over a short period to adjust to sudden changes in its surroundings (e.g., living in the plains and temporarily visiting high mountains).
• Respiration (श्वसन): The process by which living beings take in oxygen, use it to release energy from food, and give out carbon dioxide.
• Excretion (उत्सर्जन): The process of getting rid of waste products by living organisms.
• Stimulus (उद्दीपन): Changes in our surroundings that make us respond to them (e.g., touching a hot object, bright light).

2. Types of Habitats (आवास के प्रकार)

Habitats are broadly divided into two main types:

A. Terrestrial Habitats (स्थलीय आवास)

• Habitats on land.
• Examples:
  • Deserts (मरुस्थल): Very little water, hot during day, cold at night (e.g., cactus, camel).
  • Mountain Regions (पर्वतीय क्षेत्र): Very cold, windy, sometimes snowfall (e.g., snow leopard, pine trees, mountain goats).
  • Grasslands (घास के मैदान): Wide open grassy areas (e.g., lion, deer).

B. Aquatic Habitats (जलीय आवास)

• Habitats in water.
• Examples:
  • Oceans (महासागर): Salty water (e.g., fish, whales, octopuses).
  • Ponds, Lakes, & Rivers (तालाब, झीलें और नियाँ): Fresh water (e.g., lotus, water lily, frogs, freshwater fish).

3. Adaptations in Different Plants & Animals (विभिन्न पौधों और जंतुओं में अनुकूलन)

A. Desert Adaptations (Camel & Cactus)

• Camel:
  • Long legs help keep its body away from the hot desert sand.
  • Store fat in its hump for energy when food is scarce.
  • Excrete very little urine; dung is dry; does not sweat easily.
• Cactus:
  • Leaves are modified into spines to prevent water loss through transpiration.
  • Photosynthesis is carried out by the green, fleshy stem.
  • Roots go deep into the soil to absorb water.

B. Aquatic Adaptations (Fish & Lotus)

• Fish:
  • Streamlined body shape to move easily in water.
  • Gills to use oxygen dissolved in water.
  • Slippery scales to protect the body and help in swimming.
  • Fins and tail for changing directions and maintaining balance.
• Submerged / Floating Plants:
  • Stems are long, hollow, and light to hold leaves up.
  • Leaves float on the surface or are deeply divided (ribbon-like) to withstand water currents.

4. Characteristics of Living Organisms (सजीवों के लक्षण)

To prove something is "living," it must possess most or all of the following characteristics:

1. Need for Food, Water, and Air: All living things need food for energy, water for bodily functions, and oxygen for respiration.
2. Growth: All organisms grow in size and maturity over time (e.g., a puppy grows into a dog, a seed into a tree).
3. Respiration: Breathing and releasing energy from food happens in all living beings.
   • Plants: Exchange gases mainly through tiny pores called stomata.
   • Animals: Use lungs (humans), gills (fish), skin (earthworms), or spiracles (insects).
4. Response to Stimuli: Living things react to changes around them (e.g., Mimosa / Touch-me-not plant leaves fold when touched; plants bend towards sunlight).
5. Excretion: Removal of waste materials produced inside the body. Plants also excrete wastes (sometimes as gums, resins, or oxygen during photosynthesis).
6. Reproduction: Giving birth to young ones of their own kind to maintain continuity of life.
   • Animals: By laying eggs or giving birth to live young ones.
   • Plants: Through seeds, stems, roots, etc.
7. Movement: Most animals move from place to place. Plants generally stay fixed in one place, but their parts show movement (like opening of flower petals or movement towards light).
8. Lifespan: All living organisms have a fixed lifespan and eventually die.

5. Quick Revision Formula / Concept Map

$$\text{Environment} = \text{Biotic Components (Living)} + \text{Abiotic Components (Non-Living)}$$

$$\text{Living Organisms} = \text{Need Food} + \text{Grow} + \text{Respire} + \text{Respond to Stimuli} + \text{Excrete} + \text{Reproduce} + \text{Show Movement}$$