Class 6 : Science – ( English ) : Lesson 2. Diversity in the Living World
EXPLANATION AND ANALYSIS
🌍 Explanation & Analysis
🌱 Meaning of Diversity in the Living World
🧠 Diversity means variety. In the living world, diversity refers to the existence of a large number of different kinds of living organisms on Earth. These organisms differ from one another in size, shape, colour, structure, habits, and the places where they live. Such variation makes the living world rich and stable.
🌿 When we carefully observe nature, we notice grasses, shrubs, tall trees, insects, birds, animals, and human beings around us. Each of them has unique features. This wide variety of life forms present on Earth is called biological diversity.
🌎 Diversity at Different Levels
💡 Diversity is seen at many levels in the living world. It is not limited to the difference between plants and animals only.
🌱 Plants differ from animals in their structure and way of obtaining food.
🐾 Animals differ among themselves in movement, body covering, food habits, and breathing methods.
🌳 Even plants show differences among themselves, such as small herbs, medium-sized shrubs, and tall trees.
⭐ Diversity also exists among individuals of the same kind. These differences help organisms adjust to changing conditions and survive in nature.
🏞️ Habitat and Diversity
🌍 A habitat is the natural place where a living organism lives, grows, and reproduces. Every habitat provides specific conditions like air, water, light, temperature, and food. Different habitats support different kinds of living organisms.
🌊 Aquatic habitats support fishes and other water-living organisms.
🏜️ Desert habitats support organisms that can survive with very little water.
🌳 Forest habitats support a wide variety of plants and animals.
⚠️ Living organisms develop special features called adaptations that help them survive in their particular habitats.
🌱 Diversity in Plants
🌾 Plants show great diversity in their size, structure, and life span. Some plants are very small and live for a short period, while others are tall and live for many years.
🌿 Based on their structure, plants are commonly grouped into herbs, shrubs, and trees. This grouping helps us understand plant diversity easily and study them in an organised way.
🐾 Diversity in Animals
🦁 Animals also show wide diversity. They differ in body shape, body covering, mode of movement, breathing organs, and food habits.
🐦 Birds have wings and feathers that help them fly.
🐟 Fishes have fins and gills that help them live in water.
🐘 Land animals have legs suitable for walking or running.
⭐ These differences enable animals to live comfortably and safely in their surroundings.
🧠 Why Do We Group Living Organisms?
📚 The living world includes a huge number of organisms. Studying each organism separately becomes difficult. Grouping helps scientists organise this diversity in a systematic manner.
💡 By grouping organisms based on similarities and differences, scientists can study them easily, compare their features, and understand their relationships better. Grouping does not reduce diversity; instead, it helps us manage and understand it.
🌿 Importance of Diversity in the Living World
🌍 Diversity is essential for maintaining balance in nature. Each organism plays a specific role in the environment.
🌱 Plants provide food and oxygen.
🐾 Animals help in pollination and seed dispersal.
♻️ Microorganisms help in decomposition of waste materials.
⚠️ Loss of diversity can disturb the natural balance and negatively affect life on Earth.
📝 Summary of the Lesson
🌿 Diversity means variety among living organisms.
🌍 Living beings differ in structure, habits, and habitats.
🏞️ Different habitats support different organisms.
🌱 Plants and animals show wide diversity.
📚 Grouping helps in easy and systematic study.
♻️ Diversity is important for balance in nature.
⚡ Quick Recap
🌱 Diversity = variety of life
🌍 Habitat affects survival
🌿 Plants and animals are diverse
📚 Grouping helps study living organisms
♻️ Diversity maintains natural balance.
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TEXTBOOK QUESTIONS
🔒 ❓ Question 1.
Here are two types of seeds. What differences do you find among the roots and leaf venation of their plants?
📌 ✅ Answer
🔹 Wheat plant has fibrous roots.
🔸 Its leaves show parallel venation.
🔹 Kidney bean plant has a taproot system.
🔸 Its leaves show reticulate venation.
🔒 ❓ Question 2.
Names of some animals are given below. Group them based on their habitats. Write aquatic animals in area ‘A’, terrestrial animals in area ‘B’, and animals living in both habitats in part ‘C’.
Horse, Dolphin, Frog, Sheep, Crocodile, Squirrel, Whale, Earthworm, Pigeon, Tortoise
📌 ✅ Answer
🔵 Area A (Aquatic): Dolphin, Whale
🟢 Area B (Terrestrial): Horse, Sheep, Squirrel, Earthworm, Pigeon
🟣 Area C (Both land and water): Frog, Crocodile, Tortoise
🔒 ❓ Question 3.
Manu’s mother was digging out radish from the soil. She said radish is a kind of root. Examine a radish and write what type of root it is. What type of venation would you observe in its leaves?
📌 ✅ Answer
🔹 Radish is a taproot, modified to store food.
🔸 It grows deep into the soil.
🔹 The leaves show reticulate venation.
🔒 ❓ Question 4.
Look at the image of a mountain goat and a goat found in the plains. Point out the similarities and differences between them. What are the reasons for these differences?
📌 ✅ Answer
🔵 Similarities:
◾ Both are herbivorous animals.
◾ Both have horns and hooves.
🟠 Differences:
🔺 Mountain goat has thick fur and strong legs.
🔻 Plain goat has shorter fur and lighter body.
🧠 These differences are due to adaptation to different environments.
🔒 ❓ Question 5.
Group the following animals into two groups based on any feature other than those discussed in the chapter:
Cow, Cockroach, Pigeon, Bat, Tortoise, Whale, Fish, Grasshopper, Lizard
📌 ✅ Answer
🔹 Animals with backbone: Cow, Pigeon, Bat, Tortoise, Whale, Fish, Lizard
🔸 Animals without backbone: Cockroach, Grasshopper
🔒 ❓ Question 6.
As the population grows and people want more comfortable lives, forests are being cut down. How can this affect our surroundings? How can we address this challenge?
📌 ✅ Answer
🔹 Cutting forests reduces wildlife habitats.
🔸 It causes climate imbalance and soil erosion.
🔹 This challenge can be addressed by afforestation and forest conservation.
🔒 ❓ Question 7.
Analyse the flowchart. What can be examples of ‘A’ and ‘B’?
📌 ✅ Answer
🔹 A: Plants with reticulate venation, such as pea or mango.
🔸 B: Plants without reticulate venation, such as grass or wheat.
🔒 ❓ Question 8.
Raj argues that Gudhal (hibiscus) plant is a shrub. What questions can Sanjay ask for clarification?
📌 ✅ Answer
🔹 Does the plant have a woody stem?
🔸 Does it have many branches from the base?
🔹 Is its height less than that of a tree?
🔒 ❓ Question 9.
Based on the table, give examples for each group.
(a) What other similarities do plants of group A have?
(b) What other similarities do plants of group B have?
📌 ✅ Answer
🔹 Group A (Dicot): Pea, Bean
🔸 Group B (Monocot): Wheat, Rice
🟢 Group A similarities:
◾ Reticulate venation
◾ Taproot system
🟣 Group B similarities:
◾ Parallel venation
◾ Fibrous roots
🔒 ❓ Question 10.
Observe the labelled part of a duck. What difference do you observe in its feet compared to other birds? Which activity would the duck perform using this part?
📌 ✅ Answer
🔹 Duck has webbed feet unlike most birds.
🔸 Webbed feet help the duck swim easily in water.
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OTHER IMPORTANT QUESTIONS
SECTION 1 — MCQs (5 Questions)
(MCQ layout as per your locked MCQ reference style)
🔴 Q1. Which feature is common to both plants and animals?
🔵 Growth
🟢 Movement from place to place
🟡 Photosynthesis
🟣 Making food
✔️ Answer: 🔵 Growth
🔴 Q2. Which of the following animals lives both on land and in water?
🔵 Whale
🟢 Frog
🟡 Cow
🟣 Pigeon
✔️ Answer: 🟢 Frog
🔴 Q3. Reticulate venation is usually found in plants with:
🔵 Fibrous roots
🟢 Taproots
🟡 No roots
🟣 Aerial roots
✔️ Answer: 🟢 Taproots
🔴 Q4. Which pair is correctly matched?
🔵 Wheat — Reticulate venation
🟢 Rice — Parallel venation
🟡 Pea — Fibrous roots
🟣 Grass — Taproot
✔️ Answer: 🟢 Rice — Parallel venation
🔴 Q5. Which adaptation helps ducks to swim easily?
🔵 Sharp claws
🟢 Webbed feet
🟡 Strong wings
🟣 Long legs
✔️ Answer: 🟢 Webbed feet
SECTION 2 — Very Short Answer (5 Questions)
(One or two words only)
🔒 ❓ Question 6.
What type of root is found in wheat?
📌 ✅ Answer
Fibrous root
🔒 ❓ Question 7.
Name one animal that lives only in water.
📌 ✅ Answer
Whale
🔒 ❓ Question 8.
Which venation is found in pea leaves?
📌 ✅ Answer
Reticulate
🔒 ❓ Question 9.
What kind of feet does a duck have?
📌 ✅ Answer
Webbed feet
🔒 ❓ Question 10.
Name one monocot plant.
📌 ✅ Answer
Wheat
SECTION 3 — Short Answer (3 Questions)
(About 40–50 words, structured)
🔒 ❓ Question 11.
Why are plants and animals placed into different groups?
📌 ✅ Answer
🔹 Grouping helps us understand similarities and differences among living organisms.
🔸 Plants and animals differ in food habits, movement, and body structure.
🔹 Classification makes study easier and helps in identifying organisms correctly.
🔒 ❓ Question 12.
Explain why frog is called an animal of dual habitat.
📌 ✅ Answer
🔹 Frog lives both on land and in water.
🔸 It breathes through lungs on land and through skin in water.
🔹 These features allow it to survive in two different habitats.
🔒 ❓ Question 13.
How does leaf venation help in classifying plants?
📌 ✅ Answer
🔹 Leaf venation shows the pattern of veins in leaves.
🔸 Plants with parallel venation usually have fibrous roots.
🔹 Plants with reticulate venation usually have taproots, helping in classification.
SECTION 4 — Long Answer (1 Question)
(About 70–80 words)
🔒 ❓ Question 14.
Explain how different body features help animals survive in their habitats, with examples.
📌 ✅ Answer
🔹 Animals have special features called adaptations that help them survive.
🔸 Ducks have webbed feet to swim, while mountain goats have strong legs to climb.
🔹 Fish have fins to move in water, and camels have broad feet for walking on sand.
🔹 These adaptations help animals live comfortably in their surroundings.
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ADVANCE KNOWLEDGE
🌍 Why Diversity in the Living World Is More Than Just Variety
When we look around, we see plants, animals, birds, insects, and microorganisms everywhere. Some are tiny, some are huge. Some live on land, some in water, and some survive in extreme conditions like deserts, mountains, or deep oceans. This wide range of living forms is called diversity in the living world. But diversity is not just about “many kinds”; it is about how life has adapted, evolved, and survived on Earth over millions of years.
🧠 The Deep Idea Behind Classification
Early humans noticed that some plants were useful for food, some for medicine, and some were harmful. Similarly, some animals were friendly, some dangerous, and some useful for work. This curiosity led humans to group living organisms based on similarities and differences.
🔬 Scientists later realized that grouping organisms:
helps us study them easily
helps us understand relationships between organisms
helps us predict characteristics of newly discovered species
This is why classification is not memorisation—it is scientific thinking.
🌱 Hidden Patterns in Plants
At first glance, plants may seem simple, but they hide deep patterns.
🍃 Roots and Leaves Tell a Story
Plants are often grouped by:
Type of roots (taproot or fibrous)
Type of leaf venation (reticulate or parallel)
🧩 Interesting insight
These two features are connected. Plants with:
taproots usually have reticulate venation
fibrous roots usually have parallel venation
This is not a coincidence. It is the result of internal structure and growth pattern, something scientists discovered only after careful study.
🌾 Monocots and Dicots — A Silent Division
Plants are broadly divided into:
Monocots (one seed leaf)
Dicots (two seed leaves)
⭐ Advanced connection This division affects:
root type
leaf venation
arrangement of vascular tissues
overall plant strength
That is why wheat and rice grow fast with fibrous roots, while mango and pea grow stronger trunks with taproots.
🐾 Animals: Masters of Adaptation
Animals show diversity not only in shape and size but in adaptations.
❄️ Mountain vs 🌞 Plains
A mountain goat and a plains goat belong to the same group, yet they look different.
⚙️ Why? Because environment shapes bodies.
Cold regions → thick fur, strong legs
Warm regions → lighter bodies, shorter fur
🧠 This shows that habitat influences structure, not just species name.
💧 Life in Water vs Life on Land
Animals living in water face challenges like:
moving in dense water
breathing without air
So they evolved:
fins for movement
gills or special lungs
🌊 Whales, although mammals, returned to water life and adapted again—showing that evolution is flexible, not fixed.
🐸 Dual-Habitat Animals: Nature’s Experiment
Animals like frogs and crocodiles live both on land and in water.
🔍 Why is this special? Because they act as bridges between habitats, showing how life can adjust to two environments.
🧪 Frogs breathe:
through lungs on land
through skin in water
This dual ability makes them excellent examples of biological flexibility.
🧬 Backbone or No Backbone — A Major Divide
One of the most important classifications is:
Vertebrates (with backbone)
Invertebrates (without backbone)
🦴 Backbones provide:
support
protection for nerves
better movement control
That is why animals like fish, birds, and mammals can grow larger and move efficiently, while insects remain small but extremely numerous.
🐜 Why Insects Rule the Earth
Insects form the largest group of animals.
🚀 Scientific surprise More than half of all known animal species are insects.
Reasons:
small size
fast reproduction
ability to live in almost every habitat
This shows that success in nature is not about size, but adaptability.
🌳 Forests, Humans, and Balance
As humans expand cities and agriculture, forests are cut down.
⚠️ Hidden impact
loss of animal habitats
disappearance of plant species
climate imbalance
🧠 Advanced thinking When one species disappears, it affects many others. This interconnectedness is called an ecosystem network.
Protecting diversity is not kindness—it is survival strategy.
🚀 Modern Science and Biodiversity
Today, scientists use:
DNA analysis
satellite tracking
ecological modelling
to study diversity.
🧬 DNA shows that organisms which look different may be closely related, and some that look similar may be very different internally.
This has changed how scientists classify life today.
⭐ Amazing Reality Check
Humans share a large amount of DNA with plants and animals.
All life forms are connected through evolution.
Diversity is not chaos—it is order shaped by time.
🌟 Why This Lesson Matters for the Future
Understanding diversity helps students:
respect nature
think scientifically
understand environmental responsibility
🌍 The living world is not a collection of random organisms—it is a carefully balanced system, and humans are part of it.
🧠 Final Thought
Diversity in the living world teaches us one powerful lesson:
Different does not mean unequal; it means adapted.
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