Diversity in the Living World — NCERT Solutions, AI Tutor & Practice

Understand: Diversity of living organisms means the huge variety of different types of living things found on Earth.

Analyze:

• Living things differ in size, shape, colour, habitat, food habits, and many other features.
• No two kinds are exactly alike, yet some share common features.

Conclude: This variety of life forms is called the diversity of living organisms or biodiversity.

Examples:

1. In a garden you may find grass, rose plants, mango trees, butterflies, ants and earthworms all together.
2. In a pond you may find fishes, frogs, water plants (like lotus) and insects.

Understand: Plants can be grouped based on the height of the plant and the nature (thickness and hardness) of the stem.

Analyze:

| Group | Stem | Height | Example | |-------|------|--------|---------| | Herbs | Soft, green | Short | Tomato, mint | | Shrubs | Hard, woody near base, branches from base | Medium | Rose, lemon | | Trees | Very hard, thick woody trunk, branches high up | Tall | Mango, neem |

Conclude: The height and the type of stem are the main features used to classify plants into herbs, shrubs and trees.

Understand: A habitat is the place or surroundings where an organism lives, gets its food, water, air, shelter and space to grow and reproduce.

Analyze: A habitat has two kinds of components:

1. Biotic components – the living things such as plants, animals and microorganisms.
2. Abiotic components – the non-living things such as water, air, soil, sunlight and temperature.

Conclude: Thus a habitat is a home that provides both living (biotic) and non-living (abiotic) surroundings needed by an organism.

Understand: Adaptation means the special features that help an organism survive in its habitat.

Analyze — adaptations in aquatic animals (fish):

1. Streamlined body – the smooth, tapering shape helps the fish move easily through water.
2. Gills – the fish breathes using gills, which take in oxygen dissolved in water.
3. Fins and tail – help in swimming, changing direction and balancing.

Conclude: These features (streamlined body and gills) are adaptations that allow a fish to live successfully in an aquatic habitat.

Understand: Different habitats have different conditions, so organisms have different adaptations.

Analyze:

| Feature | Camel (desert) | Fish (water) | |---------|----------------|--------------| | Body shape | Long legs, large body | Streamlined body | | Movement | Broad feet to walk on sand | Fins and tail to swim | | Breathing | Lungs (breathes air) | Gills (uses dissolved oxygen) | | Water need | Can survive long without water | Lives surrounded by water |

Conclude: The camel is adapted to a hot, dry desert, while the fish is adapted to a watery habitat. Each organism has features suited to its own surroundings.

Understand: Plants and animals are both living, but they show clear differences.

Analyze:

| Feature | Plants | Animals | |---------|--------|---------| | Movement | Fixed at one place (cannot move about) | Can usually move from place to place | | Food | Make their own food by photosynthesis | Depend on plants or other animals for food | | Growth | Grow throughout life | Grow up to a certain age |

Conclude: The two main differences are movement and mode of getting food.

Understand: The pattern in which veins are arranged on a leaf is called venation.

Analyze — two types:

1. Reticulate venation – the veins form a net-like pattern.
   • Example: mango leaf, peepal leaf, hibiscus leaf.
2. Parallel venation – the veins run parallel to each other along the length of the leaf.
   • Example: grass leaf, maize leaf, banana leaf.

Conclude: Thus leaves show either reticulate (net-like) or parallel venation, and this helps in grouping plants.

Understand: Classification means arranging organisms into groups based on their similarities and differences.

Analyze — reasons it is useful:

1. It makes the study of a large variety of organisms easier and organised.
2. It helps us identify organisms quickly.
3. It shows the relationships and similarities among different groups.
4. It helps in understanding how organisms live and how they are connected.

Conclude: Classification brings order to the huge diversity of life, making it easier to study and understand living organisms.

Understand: A cactus lives in a hot, dry desert where water is very scarce, so it must save water.

Analyze — adaptations:

1. Leaves reduced to spines – ordinary leaves would lose a lot of water; spines reduce water loss and also protect the plant from animals.
2. Thick, fleshy stem – stores water, which the plant uses during dry periods.
3. The stem is green and carries out photosynthesis (the job normally done by leaves).
4. Deep or spread-out roots absorb water quickly whenever it is available.

Conclude: These adaptations help the cactus save water and survive in the harsh desert habitat.

Understand: Organisms live in different habitats — some in water (aquatic), some on land (terrestrial) and some in both (amphibian/can live in water and land).

Analyze and classify:

| Habitat | Organisms | |---------|-----------| | Aquatic (water) | Fish, Whale | | Terrestrial (land) | Camel, Lion, Lizard | | Amphibian (both) | Frog |

Conclude: Fish and whale live in water, camel/lion/lizard live on land, and the frog can live both on land and in water.

Understand:

• Biotic components are the living parts of a habitat.
• Abiotic components are the non-living parts of a habitat.

Analyze:

| Component | Meaning | Examples | |-----------|---------|----------| | Biotic | Living things | Plants, animals, microorganisms | | Abiotic | Non-living things | Air, water, sunlight, soil |

Interdependence:

• Plants (biotic) need sunlight, water, air and soil (abiotic) to grow.
• Animals (biotic) need air to breathe and water to drink (abiotic), and depend on plants for food.

Conclude: Biotic and abiotic components are interdependent — living things cannot survive without the non-living surroundings, and together they make up a complete habitat.

Understand: Plants have two main types of roots and two types of leaf venation, and these are usually linked.

Analyze:

| Feature | Grass plant | Mango plant | |---------|-------------|-------------| | Root type | Fibrous roots (many thin roots of similar size) | Tap root (one main root with smaller side roots) | | Leaf venation | Parallel venation | Reticulate (net-like) venation |

Relationship observed:

• Plants with parallel venation generally have fibrous roots (e.g. grass, maize).
• Plants with reticulate venation generally have tap roots (e.g. mango, hibiscus).

Conclude: So the type of root system is often related to the type of leaf venation, which helps in grouping plants.