Grade 6 | Science and Technology Notes of Unit 3 - Living Organisms and Their Structure | New Course 2078/2021
3.1 What is adaptation of organism?
Test Your Concept:
1. Fill in the blanks with suitable words:
a) The structural and behavioural change in the organisms that adjusts them in their environment is adaptation.
b) The organs which help organisms to adjust in the environment are called adaptive organs.
c) Spongy body is found in aquatic plants.
d) In desert, plants' leaves may be modified into thorns.
e) Gills are adaptive character of fish.
f) Camels store fat into hump.
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2. Tick the correct alternatives (MCQs):
a) Which plant has fleshy stem?
A) lotus
B) cactus
C) water lily
D) water hyacinth
Answer: B) cactus
b) How does the hard and sharp beak of an eagle adapt it?
A) helps to catch prey
B) helps to eat flesh
C) helps to fly
D) helps to crack bone
Answer: B) helps to eat flesh
c) What is the adaptive organ of a lizard?
A) strong chest muscle
B) sharp claws to grip
C) adhesive pads below toes
D) tail to grip
Answer: C) adhesive pads below toes
d) What is the adaptive feature of a frog?
A) gills to breath
B) webbed legs
C) smooth scales
D) long legs
Answer: B) webbed legs
e) What is adaptive feature of a duck for water?
A) long legs
B) feathers
C) sharp eyes
D) webbed legs
Answer: D) webbed legs
f) How is a rabbit adapted?
A) long ears and strong snout.
B) long hindlimbs and sharp eyes.
C) sharp claws and white fur.
D) short forelimbs and nostrils.
Answer: A) long ears and strong snout
3. Short answer questions (Answer in a single word/single sentence) of Unit 3 - Living Organisms and Their Structure.
a. Define adaptation.
Answer: The process of adjustment of organisms in the environment is called adaptation.
b. Write an adaptive feature of an eagle.
Answer: An adaptive feature of an eagle is - (write any one)
i) sharp eye sight.
ii) hooked beak.
iii) strong claws.
iv) large wings.
c) Write an adaptive feature of the cactus.
Answer: An adaptive feature of the cactus is - (write any one)
i) found on desert.
ii) leaves are modified into thorns.
iii) fleshy stem which store water.
d) Write an adaptive feature of rabbit.
Answer: An adaptive feature of a rabbit is - (write any one)
i) long ears.
ii) strong snout.
iii) sharp claws.
iv) make holes to live.
e) Write an adaptive feature of a rat.
Answer: An adaptive feature of a rat is - (write any one)
i) sharp claws.
ii) long ears.
iii) strong snouts.
iv) make holes to live.
f) Write name of a plant having aquatic habitat.
Answer: The name of a plant having aquatic habitat is - (write any one)
i) lotus.
ii) pistia.
iii) water lily.
iv) hydrilla.
v) water hyacinth.
g) Write an adaptive organ of fish.
Answer: An adaptive organ of fish is - (write any one)
i) gills.
ii) fins.
iii) streamlined body.
iv) air sac.
v) smooth surface.
h) Write an adaptive organ of a duck.
Answer: An adaptive organ of a duck is - (write any one)
i) webbed feet.
ii) modified beak.
iii) oily coating in feathers.
3.2 What do animals eat?
Test your concept:
1. Fill in the blanks with suitable words:
a. The animals feed on plants only are called herbivores.
b. Preparation of food in plants' bodies is autotrophic nutrition.
c. Vultures are scavengers.
d. Those who feed on living organic matter are parasite.
e. Omnivores feed on plants and animals.
f. In heterotrophic nutrition, organisms depend on others for their food.
2. Tick the correct alternatives (MCQs):
a. Which organism is a herbivore?
A) jackal
B) horse
C) dog
D) human being
Answer: B) horse
b. Which of the following is a saprophyte?
A) Vulture
B) flea
C) mushroom
D) leech
Answer: C) mushroom
c. How do parasites feed?
A) eat plants
B) eat animals
C) suck organic matters
D) suck food from host
Answer: D) suck food from host
d. What is the feature of omnivores?
A) feed on animals
B) feed on plants
C) feed on both animals and plants
D) feed on decaying organic matter
Answer: C) feed on both animals and plants
e. What is the feature of holozoic animals?
A) absorption, digestion, ingestion, egestion
B) absorption, digestion, egestion, ingestion
C) ingestion, absorption, digestion, egestion
D) ingestion, digestion, absorption, egestion
Answer: D) ingestion, digestion, absorption, egestion
3. Short answer questions (Answer in a single word/single sentence).
a. Define the mode of nutrition.
Answer: The pattern of taking food is called the mode of nutrition.
b. What mode of nutrition is found in green plants?
Answer: Autotrophic mode of nutrition is found in green plants.
c. Give an example of scavenger.
Answer: An example of scavenger is vulture.
d. What are herbivores?
Answer: Grass eating animals are called herbivores.
e. Define heterotrophic nutrition.
Answer: The mode of nutrition where animal needs ready made food is called heterotrophic nutrition.
f. What are saprophytes?
Answer: Saprophytes are those who feeds on decaying organic bodies.
g. Define holozoic animals?
Answer: Animals who eat living organic matter or just killed animals and plants are called holozoic animals.
h. What are omnivores?
Answer: Animals that feed on plants and animals both are called omnivores.
3.3 Do all animals have backbone?
3.4 Do all plants bear flowers?
Test your concept:
1. Fill in the blanks with suitable words:
a. Animals having no backbone are called invertebrates.
b. Algae are aquatic and have autotrophic nutrition.
c. Fungi have saprophytic nutrition.
d. Presence of beak and feathers are features of the class Aves.
e. Single cotyledon in seeds is feature of group monocotyledons.
f. Bryophytes are also known as amphibian plants.
2. Tick the correct alternatives (MCQs):
a. Which animal is an example of vertebrate?
A) Jackal
B) earthworm
C) butterfly
D) star fish
Answer: A) Jackal
b. Which group of plants are saprophytes?
A) algae
B) bryophytes
C) fungi
D) pteridophytes
Answer: C) fungi
c. Which is the feature of the class Reptilia?
A) breathe through skin
B) move by crawling
C) have smooth scales
D) have pinnae
Answer: B) move by crawling
d. What is the feature of dicotyledons?
A) has tap root
B) has fibrous root
C) has parallel venation
D) leaves have no petiole
Answer: A) has tap root
e. What is the feature of pteridophytes?
A) amphibian plants
B) true root, stem and leaves
C) aquatic plants
D) false root, stem and leaves
Answer: B) true root, stem and leaves
f. What is the feature of the class Amphibia?
A) need water for reproduction
B) have smooth scales over skin
C) have pentadactyl limbs
D) move by crawling
Answer: A) need water for reproduction
3. Short answer questions (Answer in a single word/single sentence).
a. Define vertebrates.
Answer: Those animals which have backbone in their body are called vertebrates.
b. Give an example of the class Aves.
Answer: An example of the class Aves is Crow.
c. Write a feature of the class Mammalia.
Answer: A feature of the class Mammalia is - They suckle milk to their babies.
d. What are cryptogams?
Answer: Non-flowering plants are called cryptogams.
e. Write a feature of pteridophytes.
Answer: A feature of pteridophytes is - They have feather like leaves.
f. What are bryophytes?
Answer: Green and autotrophic plants are called bryophytes.
g. Write an example of algae?
Answer: An example of algae is Volvox
h. Write a feature of monocotyledons.
Answer: A feature of monocotyledons is - They have fibrous root.
UNIT 3 Living Organisms and Their Structure "EXERCISE":
1. Long answer questions of Unit 3 - Living Organisms and Their Structure:
a. Write any three adaptational features of aquatic plants.
Answer: The three adaptational features of aquatic plants are -
i) Aquatic plants have spongy and flexible body.
ii) Aquatic plants have a waxy body surface.
iii) Aquatic plants have forked leaves.
b. Write any three features of dicotyledons.
Answer: The three features of dicotyledons are -
i) They have two cotyledons in seeds.
ii) They have tap root.
iii) They have petiole and reticulate venation.
c. Write any three features of pteridophytes.
Answer: The three features of pteridophytes are -
i) They have feather-like leaves.
ii) They have true roots and leaves.
iii) Their stem is underground.
d. Write any three features of fungi.
Answer: The three features of fungi are -
i) They have saprophytic nutrition.
ii) They may be unicellular or multicellular.
iii) They grow on decaying dead bodies.
e. Describe holozoic animals in short.
Answer: Animals who eat living organic matter or just killed animals and plants are called holozoic animals. Man, cat, dog, bear, giraffe, frog, fish, etc. have holozoic mode of nutrition. Holozoic animals are classified in to i) Herbivorous animals, ii) Carnivorous animals and iii) Omnivorous animals.
f. What adaptive features of a yak help it to move up and down on slopes of hills?
Answer: The adaptive features of a yak that help it to move up and down on slope of hills are -
i) broad hooves.
ii) short legs.
g. How is a lotus plant adapted for the aquatic habitat?
Answer: A lotus plant is adapted for the aquatic habitat by following ways -
i) Lotus has spongy and flexible body.
ii) Lotus has a waxy body surface.
iii) Lotus has poor root system.
Or,
A lotus plant is adapted for the aquatic habitat by the help of it's spongy and flexible body and waxy body surface with poor root system.
h. A deer has eyes at sides but a tiger has eyes in the front. Explain.
Answer: A deer has eyes at sides of it's head because this enables dear to see predators (tiger) approaching from the side as well as from behind. But a tiger has eyes in the front because this gives tiger the ability to focus on and target their prey (dear).
2. Write the differences between:
a. Fish and frog
Answer: The differences between fish and frog are -
| Fish | Frog |
|---|---|
| 1. Fish lives in water. | 1. Frog lives on land and in water both. |
| 2. The skin of fish is covered with smooth scales. | 2. The skin of frog is naked and moist. |
| 3. Fish has fins to swim in water. | 3. Frog has webbed legs to swim in water. |
| 4. Fish breathes through gills. | 4. Frog breathes through skin or mouth and lungs. |
| 5. Fish reproduce in water. | 6. Frog needs water for reproduction. |
b. Holozoic and saprophytes
Answer: The differences between holozoic and saprophytes are -
| Holozoic | Saprophytes |
|---|---|
| 1. Holozoic animals are those who eat living organic matter or just killed animals and plants. | 1. Saprophytes are those who feed on decaying organic bodies. |
| 2. Examples of holozoic animals are man, dog, bear, giraffe, frog, fish, etc. | 2. Examples of saprophytes are fungi, bacteria, mushroom and moulds, etc. |
c. Monocotyledons and dicotyledons
Answer: The differences between monocotyledons and dicotyledons are -
| Monocotyledons | Dicotyledons |
|---|---|
| 1. Monocotyledons have a single cotyledon in their seeds. | 1. Dicotyledons have two cotyledons in their seeds. |
| 2. Monocotyledons have fibrous root. | 2. Dicotyledons have tap root. |
| 3. Monocotyledons plants do not have wood in their stem. | 3. Dicotyledons plants may have wood in their stem. |
| 4. Monocotyledons plant's leaves have sheath and parallel venation. | 4. Dicotyledons plant's leaves have petiole and reticulate venation. |
| 5. Examples of monocotyledons are maize, rice, wheat, onion, garlic, ginger, sugarcane, banana, etc. | 5. Examples of dicotyledons are mustard, mango, pea, gram, bean, potato, etc. |
d. Saprophytes and parasites
Answer: The differences between saprophytes and parasites are -
| Saprophytes | Parasites |
|---|---|
| 1. Saprophytes feed on decaying organic bodies. | 1. Parasites feed on other living organism (host) and and uses host as a source of food. |
| 2. Saprophytes are alive on decaying organic bodies. | 2. Parasites are alive on host. |
| 3. Saprophytes are not harmful for living organisms and helps the environment. | 3. Parasites are harmful for the host and may lead to death. |
| 4. Saprophytes have extracellular digestion. | 4. Parasites have intracellular digestion. |
| 5. Examples of saprophytes are bacteria, fungi, mushroom and moulds, etc. | 3. Examples of parasites are mosquito, ascaris, leech, wasps, etc. |
e. Aquatic plants and desert plants
Answer: The differences between aquatic plants and desert plants are -
| Aquatic plants | Desert plants |
|---|---|
| 1. Aquatic plants are generally found in water. | 1. Desert plants are found in dry and hot desert. |
| 2. Aquatic plants have forked leaves which helps them to tolerate the water current. | 2. Desert plants leaves are either absent, very small or modified into thorns |
| 3. Aquatic plants have poor root system. | 3. Desert plants have a deep root system in order to draw water. |
| 4. Aquatic plants have flexible stem which helps them to float. | 4. Desert plants have fleshy stem which stores water. |
| 5. Examples of aquatic plants are lotus, pistia, water hyacinth, water lily, hydrilla, etc. | 5. Examples of desert plants are cactus, aloe-vera, desert lily, desert sage plant, prickly pear, etc. |
f. Bird and bat
Answer: The differences between bird and bat are -
| Bird | Bat |
|---|---|
| 1. Bird belongs to the class Aves. | 1. Bat belongs to the class Mammalia. |
| 2. Bird reproduce by laying eggs. | 2. Bat reproduce by giving direct birth to their young ones. |
| 3. Bird has no teeth but has a beak to eat and scooping water. | 3. Bat has no beak but has teeth for crushing. |
| 4. Bird is generally active during the daytime. | 4. Bat is active only during the nighttime. |
| 5. Bird is feathered, winged animal. | 5. Bat is webbed structured animal. |
g. Poikilothermic and homeothermic animals
Answer: The differences between poikilothermic and homeothermic animals are -
| Poikilothermic Animals | Homeothermic Animals |
|---|---|
| 1. Poikilothermic are animals whose body temperature adjusts depending on the environment. | 1. Homeothermic are animals that have a constant body temperature. |
| 2. Poikilothermic are alos called cold blooded animals. | 2. Homeothermic are also called warm blooded animals. |
| 3. Poikilothermic animals undergoes migration and hibernation during cold. | 3. Homeothermic animals do not undergoes migration and hibernation. |
| 4. Body temperatures of poikilothermic animals fluctuates within environmental temperature. | 4. Body temperatures of homeothermic animals fluctuates within a narrow range. |
| 5. Examples of poikilothermic animals are frog, fish, snake, toad, salamander, etc. | 5. Examples of homeothermic animals are cow, pigeon, bat, human, tiger, etc. |
3. Give reasons (Explain):
a. Bryophytes are also called amphibian plants.
Answer: Bryophytes are also called amphibian plants because they need water for reproduction.
Or,
Bryophytes are autotrophic plants which grow on damp and moist surfaces. They need water for reproduction. So, bryophytes are also called amphibian plants.
b. A fish cannot survive on land.
Answer: A fish cannot survive on land because fish does not have lungs to inhale oxygen directly from atmosphere similar to life on earth surface.
Or,
Fish has tiny blood vessels spread over the surface area of it's gills through which it gets necessary amount of oxygen dissolved in water. It cannot breathe directly through the atmospheric oxygen. So, a fish cannot survive on land.
c. A mushroom is called saprophyte.
Answer: A mushroom is called saprophyte because it feeds on dead and decaying organic bodies.
Or,
A mushroom has no chlorophyll in it. It depends on dead and decaying organic matters for food. It is types of fungi and fungi are saprophytes. So, a mushroom is called saprophyte.
d. The tiger is known as a carnivore but a cat is known as omnivore.
Answer: The tiger is known as a carnivore but a cat is known as omnivore because tiger eats only flesh of other animals but cat eats both plants and animals.
Or,
Tiger eats only animals flesh but cat eats mouse and many grains items like breads, chapati, etc. So, the tiger is known as a carnivore but a cat is known as omnivore.
e. Vultures are called scavengers.
Answer: Vultures are called scavengers because they eat the dead animals and keep the environment clean.
f. A spirogyra cannot be kept in group fungi.
Answer: A spirogyra cannot be kept in group fungi because it has chlorophyll that helps in photosynthesis to prepare food itself where fungi cannot.
Or,
Fungi are non green plants. They cannot make their own food but a spirogyra is a green plant and make it's own food. So, a spirogyra cannot be kept in group fungi.
4. Diagrammatic questions:
a. Identify and write the name of the class, habitat and adaptational features of each the animals given in the diagram.
| Duck | Rabbit | Sea Horse |
|---|---|---|
| Crocodile | Frog |
Answer:
| Name | Class | Habitat | Adaptional Features |
|---|---|---|---|
| Duck | Aves | Ponds, Lakes, River, etc. | 1. Duck has beak but no teeth. 2. Duck's skin is covered with feathers. 3. Duck's forelimbs are modified into wings. |
| Rabbit | Mammalia | Burrow | 1. Rabbit's skin is covered with fur/hair. 2. Rabbit has external ears called pinnae. 3. Rabbit suckle milk to it's babies. |
| Sea Horse | Pisces | Water | 1. Sea horse has fins to swim. 2. Sea horse has gills to breathe. 3. Sea horse's skin is covered with smooth scales. |
| Crocodile | Reptellia | Near lakes, river, ponds, etc. | 1. Crocodile move by crawling. 2. Crocodile breathe through lungs. 3. Crocodile lays eggs with hard shell. |
| Frog | Amphibia | Land and Water | 1. Frog lives on land and water both. 2. Frog has webbed legs to swim in water. 3. Frog breathe either through the skin or mouth and the lungs. |
#From above grade/class-6 science notes of unit-3"Living Organisms and Their Structure" New Course 2078/2021, we hope students will be able to:
- Identify and describe adaptational characteristics and adapted organs of animals and plants.
- Classify animals on the basis of their food with examples.
- Classify vertebrates and tell their general features.
- Find similarities and differences among flowering and non-flowering plants.
#Thanks for visiting us. We are really happy providing the notes of Grade/Class-6 Science, Living Organisms and Their Structure Notes based on new course of year 2077-2078 of Unit-3 Living Organisms and Their Structure. Please leave comments or suggestions so that we can improve.😊
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