Samacheer Kalvi Class 6 Science Solutions Term 1 Chapter 5 Living World of Animals

I. Choose the correct answer:

Question 1. The study of living things or organisms is called
(a) Psychology
(b) Biology
(c) Zoology
(d) Botany
Answer: (b) Biology
In simple words: Biology is the science that looks at all living things, like plants and animals, to understand how they work and grow.

🎯 Exam Tip: Remember that Biology is the broad study of life, while Zoology focuses on animals and Botany on plants.

Question 2. Which of the following are characteristics of living beings?
(i) Respiration
(ii) Reproduction
(iii) Adaptation
(iv) Excretion
Choose the correct sequence
(a) (i), (ii), and (iv) only
(b) (i), (ii) only
(c) (ii) and (iv) only
(d) (i), (iv), (ii) and (iii)
Answer: (d) (i), (iv), (ii) and (iii)
In simple words: Living things need to breathe (respiration), get rid of waste (excretion), make new life (reproduction), and change to fit their surroundings (adaptation). These are all key features of life.

🎯 Exam Tip: Memorize the seven essential life processes: movement, respiration, sensitivity, growth, reproduction, excretion, and nutrition, often abbreviated as MRS GREN.

Question 3. Lizards breathe through their
(a) Skin
(b) Gills
(c) Lungs
(d) Trachea
Answer: (c) Lungs
In simple words: Just like humans, lizards use lungs to breathe air, taking in oxygen and releasing carbon dioxide.

🎯 Exam Tip: Differentiate between respiratory organs for different environments: gills for water, skin for moist environments (like frogs), and lungs for land animals.

Question 4. All animals need _______
(a) Food and water only
(b) Water only
(c) Air, food and water
(d) Food only
Answer: (c) Air, food and water
In simple words: Every animal needs air to breathe, food for energy, and water to stay hydrated and for body functions to work.

🎯 Exam Tip: Remember that all living organisms require air (for respiration), food (for energy and growth), and water (for various biological processes) to survive.

Question 5. Which animal has the special organs of breathing called gills
(a) Earthworm
(b) fox
(c) Fish
(d) frog
Answer: (c) Fish
In simple words: Fish have special body parts called gills that help them take oxygen directly from the water, allowing them to breathe underwater.

🎯 Exam Tip: Gills are specifically designed for aquatic respiration, allowing oxygen extraction from water, unlike lungs which are for air breathing.

Question 6. Choose the set that represents only biotic components of a habitat.
(a) Tiger, Deer, Grass, Soil
(b) Rocks, Soil, Plants, Air
(c) Sand, Turtle, Crab, Rocks
(d) Aquatic plant, Fish, Frog, Insects
Answer: (d) Aquatic plant, Fish, Frog, Insects
In simple words: Biotic means living things. All the items in option (d) are living organisms, which are important parts of any environment.

🎯 Exam Tip: Clearly distinguish between biotic (living) components like plants, animals, and microorganisms, and abiotic (non-living) components like soil, water, air, and rocks.

Question 7. Which of the following cannot be called as a habitat?
(a) A desert with camels
(b) A pond with fish and snails
(c) Cultivated land with grazing cattle
(d) A jungle with wild animals
Answer: (c) Cultivated land with grazing cattle
In simple words: A true habitat is a natural home where specific animals and plants live without much human involvement. Cultivated land is created by humans and is not a natural habitat.

🎯 Exam Tip: A habitat is a natural environment where a species normally lives and thrives, providing all its needs for survival and reproduction.

Question 8. Birds fly in the air with the help of _______
(a) heavy and strong Bones
(b) Soft and thick Bones
(c) Hollow and light Bones
(d) Flat and thick Bones
Answer: (c) Hollow and light Bones
In simple words: Birds have bones that are not solid but hollow inside, which makes them very light. This lightness helps them fly easily without being too heavy.

🎯 Exam Tip: The lightweight, hollow bones are a key adaptation for flight in birds, along with their streamlined body and strong wing muscles.

Question 9. Paramecium moves from one place to other with the help of
(a) Pseudopodia
(b) flagella
(c) Foot
(d) cilia
Answer: (d) Cilia
In simple words: Paramecium uses many tiny hair-like structures called cilia that beat together like little oars, allowing it to swim and move around.

🎯 Exam Tip: Remember the specific locomotory structures for different microorganisms: pseudopodia for Amoeba, flagella for Euglena, and cilia for Paramecium.

Question 10. Kangaroo rat lives In _______
(a) Aquatic habitat
(b) Desert habitat
(c) Grass land habitat
(d) Mountain habitat
Answer: (b) Desert habitat
In simple words: Kangaroo rats are specially adapted to live in very dry places like deserts, where they can survive with very little water.

🎯 Exam Tip: Animals in desert habitats often have unique adaptations, such as efficient water conservation and nocturnal activity, to cope with extreme heat and dryness.

II. Multiple Choice Questions Complete the following with appropriate word(s).

Question 1. Aquatic, deserts, mountains are called _______.
Answer: Aquatic, deserts, mountains are called Habitat.
In simple words: These terms describe different types of natural homes or environments where animals and plants live.

🎯 Exam Tip: Habitats are characterized by specific physical conditions, like water (aquatic), dryness (desert), or elevation (mountain), which determine the types of organisms that can live there.

Question 2. Based on the number of cells present, animals are classified into .......... and ..........
Answer: Based on the number of cells present, animals are classified into Unicellular, multicellular.
In simple words: Living things are grouped by whether they are made of just one cell (unicellular) or many cells (multicellular).

🎯 Exam Tip: Unicellular organisms are often microscopic, while multicellular organisms can range from small insects to large animals, with specialized cells forming tissues and organs.

Question 3. Tail of a bird acts as a rudder which helps to _______
Answer: Tail of a bird acts as a rudder which helps to control the direction of the movement.
In simple words: A bird's tail works like the rudder on a boat, helping it steer and change direction while flying.

🎯 Exam Tip: The tail, along with wings, is crucial for a bird's flight dynamics, providing balance, lift, and steering capabilities.

Question 4. Amoeba moves with the help of ............
Answer: Amoeba moves with the help of Pseudopodium.
In simple words: Amoeba uses temporary, finger-like extensions of its body called pseudopodia to crawl and move around.

🎯 Exam Tip: Pseudopodia ("false feet") are also used by amoebas to engulf food particles, a process called phagocytosis.

III. True or False, If False gives the correct answer.

Question 1. A habitat is a living or dwelling place of an organism.
Answer: True
In simple words: Yes, a habitat is exactly where an animal or plant naturally lives.

🎯 Exam Tip: This is the fundamental definition of a habitat. Remember that it provides all the necessary resources for survival.

Question 2. The geographical features and environmental conditions on earth remain the same from one place to another.
Answer: False – The geographical features and environmental conditions on earth do not remain the same from one place to another.
In simple words: This statement is false because places on Earth are very different, with varied weather, land, and natural features.

🎯 Exam Tip: Earth's diverse biomes (deserts, forests, oceans, mountains) demonstrate that conditions vary greatly, leading to different adaptations in organisms.

Question 3. Amoeba is a unicellular organism and moves with pseudopodia.
Answer: True
In simple words: Yes, Amoeba is a tiny organism made of just one cell and it moves using its "false feet."

🎯 Exam Tip: This statement correctly identifies both the cellular structure (unicellular) and the mode of locomotion (pseudopodia) for Amoeba.

Question 4. Birds can see only one object at a time.
Answer: True
In simple words: Birds often have eyes on the sides of their heads, which lets them see two different things at once. However, some birds have eyes more forward, like humans, allowing for binocular vision.

🎯 Exam Tip: Most birds have monocular vision (each eye sees independently), giving them a wider field of view to detect predators, though some predatory birds have binocular vision for depth perception.

Question 5. Paramecium is a multicellular organism.
Answer: False – Paramecium is a unicellular organism.
In simple words: This is false; Paramecium is a single-celled organism, not one made of many cells.

🎯 Exam Tip: Remember that Paramecium, like Amoeba and Euglena, are common examples of unicellular organisms (protists).

IV. Complete the following

Question 1. Tropical rain forests, grasslands, and deserts are known as _______
Answer: Tropical rain forests, grasslands, and deserts are known as habitats.
In simple words: These are all names for different kinds of natural places where plants and animals live.

🎯 Exam Tip: These examples represent major terrestrial biomes, which are large ecological areas defined by their climate and dominant plant life.

Question 2. Some living things are made of a single cell, they are called a............ organism
Answer: Some living things are made of a single cell, they are called a unicellular organism.
In simple words: Living things that have only one cell are called unicellular.

🎯 Exam Tip: Unicellular organisms are the simplest forms of life and perform all life functions within that single cell.

Question 3. The breathing organ of a fish is known as _______
Answer: The breathing organ of a fish is known as gills.
In simple words: Fish breathe using special organs called gills that help them take in oxygen from the water.

🎯 Exam Tip: Gills are highly efficient for extracting dissolved oxygen from water, which is a key adaptation for aquatic life.

Question 4. The lizard _______ on the ground with its claw on its feet.
Answer: The lizard walk and run on the ground with its claw on its feet.
In simple words: Lizards use their claws to grip the ground and move quickly, either walking or running.

🎯 Exam Tip: Claws provide traction and are essential for locomotion and climbing in many reptiles, helping them navigate various terrains.

Question 5. Camel stores _______ in its hump.
Answer: Camel stores fat in its hump.
In simple words: A camel's hump is full of fat, which acts like a food and water reserve, helping it survive long periods in the desert without eating or drinking.

🎯 Exam Tip: The fat stored in a camel's hump is not water itself, but metabolizes into water and energy, a vital adaptation for arid environments.

V. Very Short Answer Questions:

Question 1. How do the birds catch their prey?
Answer: The way birds catch their prey depends on their type.

• Aquatic birds often use their beaks to slide into the water and grab their prey.
• Birds in paddy fields catch small insects using their sharp claws.

🎯 Exam Tip: When describing how birds hunt, remember to mention both their specialized body parts (beaks, claws) and their hunting techniques, linking them to their specific habitats.

Question 2. Where can we see camels in India?
Answer: Camels can be seen mainly in the state of Rajasthan in India. This region has a large desert area, making it suitable for camels.
Specifically, they are found in places like:
1. Jodhpur
2. Pushkar
3. Bikaner
4. Jaisalmer
In simple words: In India, you can mainly find camels in the state of Rajasthan, especially in its desert areas and cities like Jodhpur or Jaisalmer.

🎯 Exam Tip: When asked about the location of specific animals, identify the primary geographical region and provide examples of cities or districts if possible.

Question 3. Name the locomotory organs of an Amoeba.
Answer: Amoeba moves using finger-like projections called pseudopodia. These temporary extensions allow the Amoeba to change its shape and crawl from one place to another.
In simple words: Amoeba moves using its "false feet" which are called pseudopodia.

🎯 Exam Tip: Pseudopodia are not only for movement but also for engulfing food, a process important for Amoeba's survival.

Question 4. What are the body parts of the snake?
Answer: A snake's body is generally divided into:
1. Head (containing eyes, nostrils, and mouth)
2. Body (the long, main part)
3. Tail (the end part)
Snakes do not have limbs, but their flexible spine and scales help them move. These divisions, while not as distinct as in other animals, help in understanding their anatomy.
In simple words: A snake's body has three main parts: a head, a long body, and a tail, but it doesn't have arms or legs.

🎯 Exam Tip: When describing snake anatomy, focus on the key segments and adaptations like their lack of limbs and flexible body for movement.

Question 5. Which structure helps the bird to change its direction while flying in the air?
Answer: The tail helps the bird to change its direction while flying in the air. It works like a rudder on a boat, allowing the bird to steer and maintain balance. Birds can also adjust their wing movements for finer directional control.
In simple words: A bird uses its tail to steer and change direction as it flies through the air.

🎯 Exam Tip: The tail feathers are crucial for aerodynamic control, helping with braking, steering, and maintaining stability during flight.

VI. Short Answer Type Questions:

Question 1. Differentiate between unicellular and multicellular organisms.
Answer:

🎯 Exam Tip: Focus on the number of cells, level of organization, and method of growth as key distinguishing features when differentiating these organism types.

Question 2. Write the adaptive features of polar bears and penguins.
Answer:
Polar Bear:
1. They have short limbs, which help them conserve heat. They also have a large body size to minimize heat loss.
2. They have thick skin for insulation.
3. A polar bear has thick fur for protection against the cold climate.
4. They have a thick layer of fat under their skin to keep warm.
5. They eat food rich in fat to store energy.

Penguin:
1. They have a boat-shaped body, which helps them swim efficiently.
2. Their feathers absorb sunlight, helping them regulate body temperature.
3. They have thick skin for insulation against cold water.
4. They have a thick layer of fat deposition under the skin, similar to polar bears, for warmth.
5. They have short wings that are modified for paddling in water rather than flying in the air, allowing for excellent swimming.
In simple words: Polar bears have thick fur and fat, short legs, and large bodies to stay warm in the cold. Penguins have a streamlined body, thick skin, fat, and strong short wings that act like paddles to swim well.

🎯 Exam Tip: When discussing adaptations, connect each feature directly to how it helps the animal survive in its specific environment (e.g., thick fur for cold, streamlined body for swimming).

Question 3. Mention the feature that helps a bird to fly in the air?
Answer: Several features help birds fly in the air:
1. Their body is streamlined, meaning it's smooth and reduces air resistance.
2. Their front limbs (forelimbs) are modified into wings, specially designed for flight.
3. They have hollow and light bones, which reduces their overall body weight.
4. The body of birds is covered with feathers, providing insulation and aiding in flight dynamics.
These adaptations allow birds to be excellent flyers.
In simple words: Birds have a smooth body shape, wings instead of arms, light bones, and feathers, all of which help them fly easily in the air.

🎯 Exam Tip: Remember that bird flight is a complex process relying on a combination of anatomical features, not just wings. Hollow bones and a streamlined body are equally important.

Question 4. What are the different types of invertebrates?
Answer: Invertebrates are animals without a backbone. Some of the different types include:
1. Protozoa (these are unicellular organisms like Amoeba and Paramecium)
2. Porifera (like sponges)
3. Coelenterata (like jellyfish and corals)
4. Platyhelminthes (flatworms)
5. Aschelminthes (roundworms)
6. Annelida (segmented worms like earthworms)
7. Arthropoda (insects, spiders, crustaceans)
8. Mollusca (snails, clams, octopuses)
9. Echinodermata (starfish, sea urchins)
These groups cover a vast diversity of animals.
In simple words: Invertebrates are animals with no backbone, such as worms, insects, snails, jellyfish, and starfish.

🎯 Exam Tip: When listing invertebrate types, try to give a common example for each scientific phylum to show understanding.

VII. Answer in detail:

Question 1. Describe the various features which help Camel dwell well in the desert.
Answer: Camels have several amazing features that help them live perfectly in the desert:
1. Their long legs keep their body away from the hot desert ground, reducing heat absorption.
2. Camels can drink a large amount of water at once and store it in their bodies, which helps them survive long periods without water.
3. They produce only a small quantity of urine, which helps in conserving body water.
4. The fat stored in their hump can be broken down for nourishment and to produce metabolic water when food and water are scarce.
5. A camel has large and flat padded feet, which spread their weight and prevent them from sinking into the soft sand, making walking easier.
6. They have long eyelashes and hair in their ears to protect their eyes and ears from blowing dust and sand.
7. They can close their nostrils to avoid dust from entering their nose during sandstorms.
These adaptations make camels highly resilient in desert conditions.
In simple words: Camels have long legs to stay cool, drink lots of water at once, store fat in their humps for energy, and have wide feet, long eyelashes, and closing nostrils to handle desert sand and heat.

🎯 Exam Tip: For detailed answers on adaptations, list each feature clearly and explain *how* it specifically helps the animal survive in its challenging environment.

Samacheer Kalvi 6th Science Living World of Animals Additional Important Questions and Answers

I. Choose the best option:

Question 1. Which one of the following is a unicellular organism
(a) Fish
(b) frog
(c) Euglena
(d) Lizard
Answer: (c) Euglena
In simple words: Euglena is a tiny living thing made up of only one cell.

🎯 Exam Tip: Remember that fish, frogs, and lizards are all multicellular animals, while Euglena is a single-celled protist.

Question 2. Polar bear and Penguins dwell in _______
(a) Cold region
(b) Hot region
(c) Cold and Hot region
(d) Forest region
Answer: (a) Cold region
In simple words: Both polar bears and penguins live in very cold places like the Arctic and Antarctic, respectively.

🎯 Exam Tip: Polar bears and penguins are prime examples of animals with specialized adaptations for surviving in frigid, icy environments.

Question 3. The animal lives in water and on land.
(a) Frog
(b) fish
(c) pigeon
(d) camel
Answer: (a) Frog
In simple words: Frogs are amphibians, which means they can live both in water and on land during different stages of their life.

🎯 Exam Tip: Amphibians like frogs have unique adaptations, such as moist skin for gas exchange and strong hind legs for jumping, to thrive in both aquatic and terrestrial environments.

Question 4. Euglena moves with the help of
(a) Flagellum
(b) Cilia
(c) Pseudopods
(d) Legs
Answer: (a) Flagellum
In simple words: Euglena uses a whip-like tail called a flagellum to swim and move through water.

🎯 Exam Tip: Differentiate between the locomotory structures of different unicellular organisms: flagella for Euglena, cilia for Paramecium, and pseudopodia for Amoeba.

Question 5. Among the following, which Bird Sanctuary located in Tamilnadu?
(a) Kadalundi
(b) Bharatpur
(c) Vedanthangal
(d) Sultanpur
Answer: (c) Vedanthangal
In simple words: Vedanthangal is a well-known place in Tamil Nadu where many birds come to live and breed.

🎯 Exam Tip: When learning about sanctuaries or reserves, it's helpful to associate them with their correct geographical locations.

II. True or false. If it is wrong correct it and write.

Question 1. Unicellular organisms grow by mitotic division.
Answer: False – In unicellular organisms, the size of the cell increases as it grows.
In simple words: This is false; unicellular organisms mostly grow by getting bigger in size, not by dividing into more cells like multicellular ones do.

🎯 Exam Tip: Mitotic division in unicellular organisms primarily serves for reproduction (to create new organisms), while growth is mainly due to an increase in cell volume.

Question 2. The streamlined body of fish helps in swimming.
Answer: True
In simple words: Yes, fish have smooth, tapered bodies that make it easy for them to cut through water and swim fast.

🎯 Exam Tip: A streamlined body shape reduces water resistance, making swimming more efficient and requiring less energy.

Question 3. The tail of the bird helps it to control the direction of the movement and balance.
Answer: True
In simple words: Yes, a bird's tail is important for steering and keeping steady when it flies.

🎯 Exam Tip: The tail feathers can be fanned out or compressed to adjust air resistance, crucial for precise flight control.

Question 4. The hind limbs of birds are modified as wings.
Answer: False – The forelimbs of birds are modified as wings.
In simple words: This is false; it's the bird's front limbs (like our arms) that have become wings, not their back legs.

🎯 Exam Tip: Birds use their hind limbs for perching, walking, or hopping, while their forelimbs are specialized for flight.

Question 5. The tail of birds help in controlling the direction of the movement
Answer: True
In simple words: Yes, a bird uses its tail to guide its flight and keep balanced.

🎯 Exam Tip: Reiterate that the tail acts as a rudder, aiding in quick turns and stabilization during various flight maneuvers.

III. Name the parts in a diagram.

Question 1. In the given diagram name the A and B parts.
Answer:
A. Pseudopodia
B. Nucleus
In simple words: The diagram shows an Amoeba, where A points to its "false feet" for movement, and B points to the center part that controls the cell.

🎯 Exam Tip: Be able to identify the key structures of an Amoeba, especially its pseudopodia for movement and feeding, and the nucleus for controlling cell activities.

Question 2. In the given diagram Name the A and B parts.
Answer:
A. Cilia
B. Contractile Vacuoles
In simple words: This picture shows a Paramecium. A points to the small hairs it uses to move, and B points to parts that help it get rid of extra water.

🎯 Exam Tip: Understand that cilia are used for both locomotion and sweeping food into the oral groove, while contractile vacuoles help in osmoregulation (water balance).

Question 3. In the given diagram Name the A and B parts
Answer:
A. Flagella
B. Nucleus
In simple words: This drawing shows a Euglena. A is its tail-like part that helps it swim, and B is the main control center of its cell.

🎯 Exam Tip: Identify the flagellum as the primary means of locomotion for Euglena, and the nucleus as the organelle containing its genetic material.

IV. Give Short Answers:

Question 1. Give some examples of a unicellular and multicellular organisms.
Answer:
Unicellular organisms: Amoeba, Paramecium, Euglena.
Multicellular organisms: Fish, Frog, Lizard, Birds, Man.
These examples illustrate the diversity of life forms based on cell number.
In simple words: Tiny creatures like Amoeba are unicellular, meaning they have one cell. Bigger creatures like fish and humans are multicellular, meaning they have many cells.

🎯 Exam Tip: When providing examples, choose well-known organisms that clearly fit into each category to demonstrate understanding.

Question 2. What is meant by migration?
Answer: Migration is when an animal moves from its usual home to a different location as the seasons change. Animals usually migrate to find better food, warmer weather, or a safer place to have their young. This movement is often a regular, long-distance journey.
In simple words: Migration is when animals travel to new places for different seasons, usually to find food or a warmer home.

🎯 Exam Tip: Define migration by mentioning it's a seasonal, regular movement for survival reasons (food, breeding, climate), not just random wandering.

Question 3. Define Adaptation.
Answer: Adaptation refers to specific body features and habits that help a plant or animal live well in a particular environment. These features allow organisms to survive and thrive in their specific habitats. For instance, polar bears have thick fur to live in cold regions.
In simple words: Adaptation means how living things get special body parts or ways of acting that help them survive in their home.

🎯 Exam Tip: When defining adaptation, always mention both "body features" (like fur or gills) and "habits" (like migration or hibernation) and how they help an organism survive in its "habitat."

Question 4. What is hibernation?
Answer: Hibernation means spending the winter in a sleepy, inactive state. For example, animals like turtles do this. It helps animals save energy when food is scarce.
In simple words: It is when some animals sleep through winter to save energy.

🎯 Exam Tip: Define the term clearly and provide a suitable example to score full marks.

Question 5. Which part protects the body of fish?
Answer: Most fish have slippery scales covering their entire body. These scales act like armor, keeping the fish safe from harm and helping it move smoothly through water.
In simple words: Scales cover a fish's body and keep it safe.

🎯 Exam Tip: Remember that scales provide protection and help fish move smoothly in water.

Question 6. Name any three bird sanctuaries in Tamil Nadu.
Answer: Three bird sanctuaries in Tamil Nadu are Vedanthangal, Kodiyakkarai, and Koondhankulam. These places are important for protecting many types of birds and their natural habitats.
In simple words: Vedanthangal, Kodiyakkarai, and Koondhankulam are three bird sanctuaries in Tamil Nadu.

🎯 Exam Tip: Always list specific names accurately when asked for examples in geographical questions.

V. Detailed Answer:

Question 1. Give an account of adaptations of birds.
Answer:1. Birds have feathers covering their bodies, which help them fly by making them lighter. 2. Their mouths have changed into beaks, which they use for eating and other tasks. Beaks are shaped differently depending on what the bird eats. 3. Birds breathe using their lungs, just like many other animals. 4. Their front limbs are modified into wings, allowing them to fly. 5. They have hollow bones, which make their bodies very light. 6. With the help of a pair of clawed feet, birds can hop, move, and run on the ground.
In simple words: Birds have feathers for light flying, beaks for eating, lungs for breathing, wings for flight, hollow bones to stay light, and clawed feet for moving on land.

🎯 Exam Tip: When describing adaptations, always link each feature directly to its specific function for the bird's survival and way of life.

Question 2. Describe various adaptive features of fishes.
Answer:1. A fish's head, body (trunk), and tail join together smoothly to create a streamlined shape. 2. This streamlined shape helps the fish glide through water with little effort, making swimming easier and faster. 3. Gills are special organs that allow fish to breathe underwater by taking in oxygen from the water. 4. Most fish are covered in slippery scales, which protect their bodies from injuries and also reduce friction while swimming. 5. They have fins that help them swim, balance, and move in different directions. 6. A strong tail acts like a steering wheel and an engine, helping the fish change direction and stay balanced in the water. This design helps them live effectively in their aquatic environment.
In simple words: Fish have a smooth, streamlined body, gills for breathing underwater, scales for protection, and fins and a strong tail for swimming and steering.

🎯 Exam Tip: Always explain how each feature helps the fish survive and thrive in its water environment, detailing the purpose of each adaptation.