The Living Organisms- Characteristics and Habitats

 

Most of the children in your class may belong to different cities and villages. Ask them out about the climate, the kind of plants that grow there and the type of animals found there. Do you Find any difference in these organisms from place to place?

Let us look at some examples. Shimla and Kashmir are very cold places. The trees on the hills are very tall and different from those found in Andhra Pradesh and Haryana. Similarly, in a desert region like Jaipur or Jodhpur, the climate is extremely hot. Plants and animals found there are also different from those found in Shimla.

 

So, some places are cold, others being hot and humid, and some places are very dry and humid This is the reason that living organisms are also of various kinds.

 

Can you think of a place, where there may not be any living being? In the deserts or even inside the soil, in the dark corners of your house, including kitchens, you can find various types of animals. You will be amazed to know that even in the opening of the volcanoes, some tiny organisms (bacteria) are found.

 

ORGANISMS AND THE SURROUNDINGS WHERE THEY LIVE

You can easily find the camels in desert. But in the hills and mountainous areas, mountain goat and yak are commonly found.

On a beach, we can find turtle, crabs and tortoises on the sand.

Similarly, we can find different types of plants and trees in various regions. Plants of one region are very different from those found in another region.

We can see that the surrounding of a place being the same but different animals and plants are found there.

 

HABITATS

The animals and plants in the sea are surrounded by saline (salty) water. Most of the animals living in the water take in air (oxygen) dissolved in it. However, in the desert, sea-animals cannot survive. Lets take the examples of a fish and a camel. Fish have gills to respire, whereas camels have lungs.

 

Hence, these two animals have different body structures to live in different habitats.

 

The surrounding or the place where an organism lives is called its habitat. Habitat is the place where environmental conditions are favourable for the existence of a living organism and where it can survive, breed and flourish. A habitat offer food, shelter and favourable climatic conditions to the organism.

 

A habitat includes both abiotic (physical) and biotic (living) components. All living things of habitat are its biotic components such as animals, plants, bacteria, etc. All the non-living things of habitat are its abiotic components such as air, water, temperature, etc.

 

The tropical rainforests are found between equator and two tropics Cancer and Capricorn. The tropical rainforests have more diversity than any other habitat on this planet.

 

Types of habitats

Some common habitats are deserts, mountains, forests, grassland, garden, soil, pond, river, field, tree, ocean, lake, etc. All these habitats can be grouped into three major categories:

(a) Terrestrial habitats

(b) Aquatic habitats

(c) Aerial habitats

 

(a) Terrestrial habitats

The habitat comprising of the land is known as terrestrial habitats. Because of the greatest variations in abiotic factors, the land has the largest variety of habitats. Some of the common examples of terrestrial habitats are grassland, forest, soil, garden, desert, mountains, field, etc Some of these are follows:

 

1.  Desert habitats: They get very little rain hence they are dry. They may be hot and dry on cold and dry. Camel, snake, rat, and fox are the animals found in desert habitat. The plants found in such habitat are cactus, babool (Acacia), palm, agave, etc.

 

2.  Grassland habitats: They get moderate rain. They are partly dry areas with grass and fev trees. Examples of organisms found in grasslands are- giraffe, wild buffalo, zebra and kangaroo.

 

3.  Forest habitats: They get heavy rain. They are warm and evergreen. Amazon rainforest i the largest rain forest of the world. Examples of organisms found in forest habitat are snakes elephants, tigers, bear, monkeys, etc. Among plants, the main varieties are teak, sandalwood  banyan, mahogany, Gul mohar, etc.

 

4.  Tundra habitats: They are very cold and dry areas, covered with snow. Example of organism found in these regions are polar bear, reindeer, penguin and some grasses.

 

(b) Aquatic habitats

1.  These include organisms that live in water. Aquatic habitats are further subdivided into the following types:

 

2.  Freshwater habitat: Rivers, lakes, ponds, and streams are examples of freshwater habitats. Animals like fish, ducks, frogs, and insects live in freshwater. Some plants, such as lotus can be found floating on the surface of the pond.

 

3.  Marine habitat :Oceans and seas form the largest habitat on the planet. They provide home to planktons blue whale, etc. Examples of organism found in marine habitat are planktons, jellyfish, crab, starfish, dolphin, clownfish, etc.

 

 

(c) Aerial habitat:

The animals or organisms that spend most of their time in air are called aerial organisms and this habitat is known as aerial habitat. For examples, birds, bats and certain flying insects.

 

Some organisms spend most of their lives on trees. They eat, sleep and play in the tree canopy. Such animals are called arboreal animals. Monkey and squirrel are arboreal animals.

 

ADAPTATIONS

Different types of habitats have different climatic conditions. So, only those organisms can survive in a particular habitat that have characteristics which help them to cope up with that particular environment. The organisms that fails to adapt get eliminated. The development of characteristics which help an organism to survive in a particular environment is known as adaptation.

Generally, organisms adapt to their habitat by the following means:

 

1.  Changes in the body: Humans, plants and animals have developed specialized body parts that help them to survive in their habitat.

 

2.  Changes in the behavior: Many organisms develop some specialized behavior to survive in their habitats. For example, bear undergoes a long winter sleep to overcome harsh weather conditions and shortage of food. It is called hibernation. Similarly, the summer sleep is called aestivation.

 

3.  Changes in the location: Certain animals, namely, birds and fish during harsh climatic changes move away from one location to the other till the extreme conditions prevail. They return only after the weather conditions change to the normal. Such a movement is known as migration.

 

Fish also shows many adaptations for aquatic life. These includes streamlined body, and gills for breathing in the water. Gills help the fish to obtain oxygen dissolved in water. When fish is taken out of water, it dies within no time. Fish also have slippery scales on the body which provide protection against predators and help in easy movement through water.

 

Habitat adaptation in plants

There are three types of adaptations in plants on the basis of habitat, as follows:

 

(a) Xerophytes: The plants that grow in the desert are called xerophytes. Common xerophytic plants are Agave, Asparagus, Euphorbia, Yucca and Cactus. Following are the xerophytic adaptations in plants:

 

1.  The stem is swollen to store water.

2.  The leaves are modified to spines to minimize the water loss in dry condition.

3.  The stem is green due to the presence of chlorophyll. Hence, it helps to carry out photo- synthesis.

4.  They have very extensive root systems which penetrate deep into the soil in search of water.

5.  Stomata are few, sunken in pits or covered with fine hairs.

6.  Their leaves are coated with cuticle to check the loss of water.

 

 

(b) Hydrophytes: These plants grow at a places where there is lot of water or the areas which Hydrophytet throughout the year. Common hydrophytic plants are: lotus, Utricularia, Pistia Vallisneria, Hydrilla, etc. Following are the characteristics of hydrophytic plants:

 

1.  Leaves of the plants like lotus and water Lily have a waxy covering that prevents their rotting.

2.  Leaves of some aquatic plants have air chambers that allow them to float on water.

3.  The cuticle and stomata are absent in these plants.

4.  These plants have poorly developed root system.

 

(c) Mesophytes: The plants grow in moderate conditions of light, temperature, water and oxygen. Neem, apple, lemon and orange are some of the mesophytic plants. Following are the mesophytic adaptations in plants :

 

1.  These plants have well developed roots with root hairs.

2.  The stems of these plants are solid and branched.

3.  These plants have stomata on both sides of leaves.

4.  These plants have large leaves, which are broad and thin and have various shapes.

 

 

A JOURNEY THROUGH DIFFERENT HABITATS

(a) Adaptations in Terrestrial Habitats

 

(i) Deserts: Deserts are the areas which receive very little or no rainfall, hence there is a shortage of water. Generally, deserts are covered with sand, having little or no vegetation. So, the dominant features of deserts are high temperature and shortage of water. In such climatic conditions, plants and animals have to protect themselves from strong heat and excessive loss of water. The animals and plants have developed some adaptations (features) to survive in deserts. These are given below.

 

Adaptations in Desert Animals:

·     In camel, the feet have leathery soles which help them to walk on the sand. The legs are long which help to keep the camel's body away from the heat of the sand.

·     Camel excretes small amount of urine to save water.

·     Some other desert animals like desert rat, desert snake, mongoose, scorpions, etc., come out from the burrows only during night. They stay in burrows during daytime when it is very hot.

·     The desert rats, snakes and other animals excrete very small amount of urine to con- serve water in their body.

 

Adaptation in Desert Plants

The plants in deserts are well adapted to high temperature and shortage of water. The adaptations that help them to survive in deserts are:

 

·     The roots are very long which penetrate deep in the soil in search of water.

·     The leaves are either very small or reduced to spines to prevent loss of water.

·     The stem is modified into fleshy, green, leaf-like structure. It stores food and water. The process of photosyntheis is also carried out by such a green stem.

·     The stem and leaves are covered with a thick waxy layer called cuticle which prevents the loss of water from it.

 

(ii) Mountain Regions: The climate in mountain region is cold and windy. In very cold and gh mountains, snowfall is observed in winter. Still a large variety of plants and animals survive mountain regions. Some common features or adaptations in animals and plants surviving in mountains are discussed below.

 

Adaptation in Mountain-Animals

The animals living in mountain regions have to withstand extremely cold environment and good amount of rainfall. Some of the commonly found animals in mountain areas are yak, mountain goat, snow leopard, etc.

 

·     Yak is the most common animal found in mountains. It has long hair to protect it from cold. It has short but thick legs, that help it to walk in snow easily. It uses its hooves and horns to clear off the ice from ground for grazing.

·     The mountain goat or rocky mountain goat has long hair that protect it from cold and keep the body warm. It has strong hooves and legs that help in climbing the rocky slopes of mountains.

·     The snow leopard has a layer of thick fur on its body which keeps it warm and protects from the extreme cold.

 

It has a thick layer of fat beneath its skin that provides insulation and protection from cold. It has small ears and rounded body which reduces the loss of body heat It has powerful legs with big feet that prevent it from sinking into soft snow.

 

Adaptation in Mountain-Plants

• The plants are cone-shaped so that snow can slide off easily.

• They grow close to the ground.

• The leaves of these plants are needle shaped to reduce transpiration.

 

(iii) Grassland and Forest

Grassland is an area of land that is covered mainly with grasses and a few trees. Lion, deer, bison, giraffe, hyena, etc., are the main animals living in grassland. The features or adaptations found in such animals are discussed below:-.

 

Adaptations in Animals

Lion: The lion has long, strong and sharp claws in its front feet that help to catch the prey like deer. These claws can be withdrawn inside the toes. They have eyes present in front of the head which help to provide correct idea of location of its prey.

 

Deer: The deer has long legs and strong muscles that help it to run fast and jump high. They have big ears to hear the movements of predators very easily. The deer has big eyes on the sides of its head that enables it to see in all the directions at once.

 

The brown colour of grassland animals camouflage with the grasses and bushes in the surroundings. It helps them to hide in dry grassland without being noticed by the predators.

 

The animals living in forests (rainforests) show some special features such as camouflage to escape from enemies. Some of them have specialized eating habits such as parrots and toucans have long and curved beaks to crack open the nuts-shells.

 

Adaptations in Plants

·     The plants growing in grasslands are small and long grasses with flexible stems that prevent the grasses from breaking due to strong winds.

·     The roots are strong and well developed to absorb water.

·     Small and thin leaves of plants help to reduce the loss of water due to transpiration.

·     In rainforests, the vegetation is very dense that allow the wild animals to hide easily. Tall trees have broad and grooved leaves that absorb much sunlight for photosynthesis.

 

(b) Adaptations in Aquatic Habitats

Oceans

·     Fish have the streamlined shape. This shape helps them in swimming. Special organs called gills allow fish to breathe in water.

·     Some animals, which do not have streamlined shape, stay deeper in the ocean and catch the prey moving around then.

·     Squid and octopus are examples of sea animals. Some sea animals such as dolphin and whales breathe air through nostrils (blowhole) because they do not have gills.

·     These animals remain in water for long time without breathing. When they swim near the water surface, nostril (which is present on the upper part of their headl allow them to breathe.

·     The body of fish is also covered with mucous and scales.

·     Tiny algae called phytoplanktons are found on the surface of ocean water.

 

Ponds and lakes

·     Some aquatic plants and amphibians such as frog are found in ponds.

·     Frog can live in both the habitats i.e.; terrestrial and aquatic, but water is essential for fertilization as they lay eggs in water. They have strong back legs for leaping on land. Their webbed feet help them to swim in water.

·     The stem of aquatic plants are long, hollow and narrow, to withstand water currents without getting damaged.

·     Leaves of water plants have a waxy covering that prevents them from rotting. Leaves of some aquatic plants have air chambers that allow them to float on water.

 

CHARACTERISTICS OF ORGANISMS

You have studied about various habitats of living organisms and also their adaptations in different or adverse conditions. Now let us study about the features of living organisms and how they are different from non-living things. A chair, table, stone or coins are all non-living things but dogs, cats, monkeys, humans, buffaloes or cows are all living things.

 

The commonly found characteristics in living organisms are:

(a) Nutrition

(d) Excretion

(g) Respond to stimulus

(b) Growth

(e) Reproduction

(h) Fixed Life span

(c) Respiration

(f) Movement/locomotion

 

(a) Nutrition: In order to stay alive, all living organisms need food. Most of the plant (containing chlorophyll) prepare their food using water, carbon dioxide and chlorophyl in the presence of sunlight. This process is called photosynthesis. That is why, plants are called autotrophs.

 

Animals depend on outside sources like plants and animals for their food. Hence they are called heterotrophs. Food is essential for living organisms as it provides energy for growth and to carry out various life processes.

 

Non-living things do not need food, air and water. For example, a stone or rock remains on the field without any food, water and air.

 

(b) Growth: All living things grow, which results in an increase in size, and weight. Significant growth could be observed both in plants and animals. A seedling grows into a tree within a few years. A calf grows into a cow or a bull within 3-4 years. Similarly, a newborn baby becomes an adult within a span of 20 years.

 

In living organisms, the growth is internal permanent and irreversible process. For example, once a baby grew into an adult. it cannot become a baby again.

 

If any part of our body gets injured, the body itself repair it in few days. If a branch of a tree is cut, the cut end shows new growth. New branches come up within a few days.

 

Non-living things do not have the ability to grow and self-repair. The growth in non-living things is external and reversible. It takes place by the addition of some materials externally. A building and a plant both grow in height. Can you tell the difference between the growth of a plant and the growth of a building?

 

 

c) Respiration or breathing: All living beings plants or animals need energy for their life- activities. This energy is obtained by the food in the presence of oxygen. The oxygen is derived from air through the process of respiration.

 

Some animals may have a different mechanism for the exchange of gases. For example, the earthworms breathe through the pores present on their skin and fish have gills for breathing in the air dissolved in water.

 

Plants also respire and the exchange of gases takes place through their leaves. Leaves take in air through the minute pores called stomata present on their surface. Plants use carbon dioxide and produce oxygen during the daytime, when they synthesise their food, but they respire throughout day and night

 

Plants produce more oxygen during photosynthesis than they consume it in respiration Non-living things do not respire or breathe at all.

 

 

d)Excretion: All living organisms have ability to excrete waste materials from their body. As we know that all living organisms take food to fulfil the requirement of energy, but the amount of food they eat is not completely used up by them. The undigested food have to be removed from the body as waste.The process of getting rid of wastes by the living organisms is known as excretion

 

Plants also excrete harmful poisonous materials produced in plant body. Some plants remove waste products as secretion through stomata. In some plants, wastes are given out in the form of gum or thick fluid called latex In same plants, the waste products are stored within different plant parts as these are not harmful.

 

In humans and other animals, wastes are removed from the body in the form of urine, sweat, and faeces (solid wastes). All animals have special organs for excretion, such as kidneys, gills and sweat glands.

 

  

e) Reproduction: "The ability of plants  and animals to produce the young ones of the own kind is called reproduction". It is a unique characteristic of living organisms That is why, continuity of life is maintained nature.

 

All living organisms in nature i.e. animals, plants. and microorganisms reproduce and give rise to their offspring. For example, a cat produces kittens which grow into adult cats. Some animals produce their young ones through eggs. For example, birds and reptiles. Some animals give birth to the young ones, for example, mammals Thus, new life originates from pre-existing life Non-living things cannot reproduce.

 

Plants also differ in the mode of reproduction Many plants reproduce through seeds, some other plants reproduce through plant parts other that seeds. For example, a part of potato with a bud grows into a new plant. This type of reproduction is called vegetative propagation.

 

Some plants reproduce through cuttings. If living things could not reproduce, can you imagine what would happen?

 

 

[f) Movement ог locomotion: All living things show movement. Most of the animals can move from one place to another but there are some animals such as sponge and corals that cannot move from one place to another. However, all living organisms exhibit body movement.

 

Most of the plants are anchored in soil, hence they cannot move from one place to another. But plants show different types of movements such as the stem of a plant moves towards sunlight, the roots grow downwards in the soil, etc.

 

A bus, car and truck (non-living objects) also move. Is this movement different from the movement of animals? These objects do not move on their own as living organisms can do. The living beings move in search of food, to protect against enemy, etc.

 

(g) Response to stimuli: If there are any changes in our surrounding such as hot object or cold weather, our body responds to these changes. These changes are called stimuli. If our hand touches a spiny leaf of cactus, we respond quickly by withdrawing our hand. When we suddenly move from a bright sunlight into a dark place, we will not be able to see anything for a moment. Some animals such as cockroach and earthworm respond to light by moving away from it.

 

Plants also respond to stimuli. There are some sensitive plants such as Mimosa (also known as touch-me-not) which curls up its leaves upon being touched. The touch is the stimulus to which the sensitive plant responds by folding its leaves.

 

Hence, all living organisms show response to stimuli such as temperature, touch, light, water, sound and gravity.

 

Roots of the plants have a tendency to grow towards gravity (i.e; downwards) and stem tends to grow against it (i.e., upwards). This response of stem and roots is called geotropism.

 

 

(h) Life span: All living organisms have a definite life span or life cycle. This means that their life has a beginning and an end. They take birth, grow, reproduce, and eventually die. Their offspring too undergoes the same cyclic changes.

 

The period during which an organism completes its life cycle is called its life span. It may be as short as in case of some bacteria (20 minutes) or it may be as long as 400 years or more as in case of some marine animals.

 

Non-living things do not have a fixed or defined life-span. The life span of non-living things can be increased by improving the technology.

 

WHAT IS LIFE?

We have seen some of the striking characteristics of living organisms. Sometimes, it is not easy to distinguish between living and non-living. For example, the seeds of plants. Are they living or non-living? In Washington, two thousand years old chinese lotus seeds were germinated to produce pink lotus flowers. Seeds can be stored for a long period. During storage, the dry seeds do not show any sign of life. When ideal conditions for germination are provided, the seeds spring to life and exhibit clear sign of life.

 

Similarly, during hibernation, the animals do not eat, move or perform any activity of living being. They become fully active when suitable conditions reappear.

 

Snakes, turtles, frogs, mouse and many other animals hibernate during winter. In the same way. some animals enter into a long sleep during summer. This is called aestivation.

 

So, we find it extremely difficult to give a proper definition of life. We can only describe some of the biological functions that living organisms can perform and which non-living organisms cannot perform.

 

 

IMPORTANT TERMS
Adaptation	The changes in the structure or behaviour of an organism that help it to survive in a particular habitat.
Habitat	The area where particular organisms live. The surrounding where living organisms plants and animals live is called their habitat. The various habitats grouped into three major categories: (a) Terrestrial (b) Aquatic and (c) Aerial habitat.
Biotic components	Living components of a habitat. The living organisms such as plants and animals are called biotic components.
Abiotic components	Non-living components of a habitat, such as soil, water, air, temperature, etc.
Xerophytes	Plants that grow in very little water or desert.
Hydrophytes	Plants that grow in the water.
Mesophytes	Plants that grow in moderate conditions of light, temperature, air and water.
Reproduction	Giving birth to its own kind.
Stimulus	A change in the immediate environment of an organism, which produces a change in the activities of the organism.
Migration	The seasonal movement of animals from one region to another.
Hibernation	The period of reduced activity in some animals during winter months.
Aestivation	The period of long sleep (by animals) during summer.

 

Exercise

 

 

 

Q1. What is a habitat?

A) A group of similar organisms

B) The surrounding or place where an organism lives

C) The abiotic components of an environment

D) The biotic components of an environment

 

Answer: B) The surrounding or place where an organism lives

Explanation: A habitat is the place where environmental conditions are favorable for the survival, breeding, and flourishing of an organism. It provides food, shelter, and suitable climatic conditions.

 

Q2. Which of the following is an example of a terrestrial habitat?

A) Pond

B) Ocean

C) Forest

D) Lake

 

Answer: C) Forest

Explanation: Terrestrial habitats include land-based environments such as forests, grasslands, deserts, and mountains, where organisms adapt to land conditions.

 

Q3. What is unique about organisms living in aquatic habitats?

A) They breathe air directly from the atmosphere

B) They rely on water to provide dissolved oxygen

C) They do not need oxygen for survival

D) They cannot survive in terrestrial habitats

 

Answer: B) They rely on water to provide dissolved oxygen

Explanation: Aquatic organisms, such as fish, extract oxygen dissolved in water through gills, which is essential for their survival.

 

Q4. Which of the following organisms is correctly matched to its habitat?

A) Camel – Grassland

B) Giraffe – Desert

C) Polar bear – Tundra

D) Monkey – Aquatic

 

Answer: C) Polar bear – Tundra

Explanation: The polar bear is adapted to live in the cold and snowy tundra habitat, which has extreme conditions of cold and dryness.

 

Q5. Which habitat is characterized by heavy rainfall and a warm climate?

A) Desert

B) Grassland

C) Tundra

D) Forest

 

Answer: D) Forest

Explanation: Forests, particularly tropical rainforests, receive heavy rainfall and have a warm and evergreen environment, making them rich in biodiversity.

 

Q6. What are arboreal animals?

A) Animals that live in water

B) Animals that spend most of their lives in trees

C) Animals that live underground

D) Animals that live in snowy regions

 

Answer: B) Animals that spend most of their lives in trees

Explanation: Arboreal animals, such as monkeys and squirrels, live, eat, sleep, and play in the tree canopy.

 

Q7. Which is the largest habitat on Earth?

A) Tundra

B) Grassland

C) Marine

D) Terrestrial

 

Answer: C) Marine

Explanation: Marine habitats, which include oceans and seas, are the largest habitats on Earth and provide homes to a vast diversity of organisms.

 

 

Q8. What is the main characteristic of desert habitats?

A) Heavy rainfall and high humidity

B) Moderate rainfall and dense vegetation

C) Very little rainfall and dry conditions

D) Snow-covered areas

 

Answer: C) Very little rainfall and dry conditions

Explanation: Deserts are characterized by their dry climate with minimal rainfall, making them arid regions. The plants and animals in these areas are adapted to conserve water.

 

Q9. Which of the following animals is typically found in a grassland habitat?

A) Camel

B) Polar bear

C) Giraffe

D) Penguin

 

Answer: C) Giraffe

Explanation: Grasslands, which have moderate rainfall and sparse trees, are home to animals like giraffes, wild buffalo, and zebras that graze on the grasses.

 

Q10. What makes tropical rainforests unique compared to other habitats?

A) They have very low biodiversity

B) They are found near the poles

C) They have the highest biodiversity on the planet

D) They have no biotic components

 

Answer: C) They have the highest biodiversity on the planet

Explanation: Tropical rainforests, located between the Tropic of Cancer and Tropic of Capricorn, are rich in biodiversity due to their warm and moist environment.

 

Q11. Which of the following is NOT an abiotic component of a habitat?

A) Air

B) Water

C) Bacteria

D) Temperature

 

Answer: C) Bacteria

Explanation: Abiotic components include non-living things like air, water, and temperature. Bacteria are living organisms and part of the biotic components.

 

Q12. Which aquatic habitat is characterized by salty water?

A) River

B) Pond

C) Lake

D) Ocean

 

Answer: D) Ocean

Explanation: Oceans and seas contain saline (salty) water, distinguishing them from freshwater habitats like rivers and lakes.

 

Q13. What is the primary mode of respiration in fish?

A) Lungs

B) Gills

C) Skin

D) Trachea

 

Answer: B) Gills

Explanation: Fish use gills to extract oxygen dissolved in water, which is essential for their survival in aquatic habitats.

 

Q14. What is an aerial habitat?

A) A habitat found on land

B) A habitat in water

C) A habitat in the air

D) A habitat in trees

 

Answer: C) A habitat in the air

Explanation: Aerial habitats refer to environments in the air where organisms like birds, bats, and flying insects spend most of their time.

 

Q15. Which of the following plants is commonly found in desert habitats?

A) Lotus

B) Cactus

C) Mahogany

D) Teak

 

Answer: B) Cactus

Explanation: Desert plants like cacti are adapted to dry conditions and conserve water through features such as spines and thick stems.

 

Q16. Which of the following animals is adapted to live in a tundra habitat?

A) Elephant

B) Kangaroo

C) Polar bear

D) Dolphin

 

Answer: C) Polar bear

Explanation: Polar bears are well-adapted to the cold, snowy conditions of tundra habitats with their thick fur and fat layers for insulation.

 

Q17. What term is used to describe organisms that spend most of their lives in trees?

A) Aquatic

B) Aerial

C) Arboreal

D) Terrestrial

 

Answer: C) Arboreal

Explanation: Arboreal animals, such as monkeys and squirrels, are adapted to live, eat, and sleep in trees.

 

 

Q18. What is the process by which organisms develop characteristics to survive in a particular habitat called?

A) Migration

B) Hibernation

C) Adaptation

D) Camouflage

 

Answer: C) Adaptation

Explanation: Adaptation refers to the development of characteristics in organisms that help them survive in their specific environment.

 

Q19. Which of the following is an example of behavioral adaptation?

A) Thick fur in polar bears

B) Long winter sleep in bears

C) Hollow stems in aquatic plants

D) Spines in desert plants

 

Answer: B) Long winter sleep in bears

Explanation: Behavioral adaptations include actions animals take to survive, such as hibernation in bears to endure cold and food scarcity.

 

Q20. What type of plants are adapted to live in desert conditions?

A) Hydrophytes

B) Mesophytes

C) Xerophytes

D) Epiphytes

 

Answer: C) Xerophytes

Explanation: Xerophytes, such as cacti, are plants adapted to survive in deserts with features like water storage and reduced leaves.

 

Q21. Which adaptation helps desert animals conserve water?

A) Thick fur

B) Long legs

C) Small amount of urine

D) Camouflage

 

Answer: C) Small amount of urine

Explanation: Desert animals, like camels and desert rats, excrete very little urine to conserve water in dry conditions.

 

Q22. What feature allows hydrophytic plants to float on water?

A) Thick stems

B) Hollow roots

C) Air chambers in leaves

D) Waxy coating on stems

 

Answer: C) Air chambers in leaves

Explanation: Air chambers help aquatic plants, like water lilies, float on water by providing buoyancy.

 

Q23. Which of the following animals is an example of migration?

A) Yak

B) Arctic tern

C) Snow leopard

D) Desert rat

 

Answer: B) Arctic tern

Explanation: Migration refers to animals moving from one location to another due to harsh climatic conditions, as seen in Arctic terns.

 

Q24. Which plant adaptation is common in mountain regions?

A) Needle-shaped leaves

B) Hollow stems

C) Waxy leaves

D) Spines

 

Answer: A) Needle-shaped leaves

Explanation: Needle-shaped leaves reduce water loss and help mountain plants withstand cold and snowy conditions.

 

Q25. Which animal adaptation is common in forests?

A) Webbed feet

B) Camouflage

C) Thick fur

D) Long necks

 

Answer: B) Camouflage

Explanation: Animals in forests often use camouflage to blend in with their surroundings and escape predators.

 

Q26. What feature is unique to dolphins and whales among sea animals?

A) Gills for breathing

B) Streamlined body

C) Blowholes for breathing air

D) Scales on the body

 

Answer: C) Blowholes for breathing air

Explanation: Dolphins and whales use blowholes to breathe air at the surface, unlike fish that rely on gills.

 

Q27. What is the term used to describe plants that prepare their own food through photosynthesis?

a) Heterotrophs

b) Omnivores

c) Carnivores

d) Autotrophs

 

Answer: d) Autotrophs

Explanation: Plants with chlorophyll use sunlight, water, and carbon dioxide to produce food through photosynthesis. Hence, they are called autotrophs.

 

Q 28. How is the growth in non-living things different from that in living things?

a) It is internal and permanent.

b) It is external and reversible.

c) It involves self-repair.

d) It is caused by reproduction.

 

Answer: b) It is external and reversible.

Explanation: Growth in non-living things occurs externally by adding materials (e.g., a building's height) and can be undone, unlike internal and permanent growth in living beings.

 

Q29. Which part of the plant is primarily responsible for gas exchange during respiration?

a) Roots

b) Stomata

c) Flowers

d) Branches

 

Answer: b) Stomata

Explanation: Stomata are tiny pores on the surface of leaves that facilitate gas exchange in plants.

 

Q30. How do some plants excrete their waste materials?

a) Through flowers

b) By producing latex or gums

c) By shedding leaves

d) Through chlorophyll

 

Answer: b) By producing latex or gums

Explanation: Some plants excrete waste as latex or gums, while others use stomata for excretion.

 

 

Q31. Which plant is commonly known for responding to touch by folding its leaves?

a) Lotus

b) Mimosa

c) Banyan

d) Mango

 

Answer: b) Mimosa

Explanation: The Mimosa plant, also called "touch-me-not," folds its leaves in response to touch as a defense mechanism.

 

Q32. Which of the following has the shortest known life span?

a) Human

b) Marine turtle

c) Bacteria

d) Elephant

 

Answer: c) Bacteria

Explanation: Some bacteria have a life span as short as 20 minutes, making them the organisms with the shortest known life span.

 

Q33. What triggers dormant seeds to "spring to life"?

a) External forces like wind

b) Storage in dry conditions

c) Suitable conditions for germination

d) Lack of air

 

Answer: c) Suitable conditions for germination

Explanation: Dormant seeds become active and start showing life when provided with ideal conditions for germination, such as moisture, warmth, and air.

 

 

Q34. Which of the following movements is observed in plants?

a) Movement of roots towards sunlight

b) Movement of stem against gravity

c) Movement of branches towards water

d) Movement of leaves towards sunlight

 

Answer: d) Movement of leaves towards sunlight

Explanation: Leaves of plants move toward sunlight, a process known as phototropism.

 

Q35. What is the primary role of oxygen in the respiration process of living organisms?

a) To produce carbon dioxide

b) To generate energy from food

c) To initiate photosynthesis

d) To repair body parts

 

Answer: b) To generate energy from food

Explanation: Oxygen helps in breaking down food molecules to release energy, a process essential for life activities.

 

Q36. Which method of reproduction involves new plants growing from parts other than seeds?

a) Pollination

b) Fertilization

c) Vegetative propagation

d) Spore formation

 

Answer: c) Vegetative propagation

Explanation: In vegetative propagation, plants grow from parts like stems, roots, or leaves (e.g., potatoes and onions).

 

Q37. What is geotropism in plants?

a) Growth of plants towards sunlight

b) Growth of roots towards gravity and stems against it

c) Growth of plants towards water

d) Growth of plants towards carbon dioxide

 

Answer: b) Growth of roots towards gravity and stems against it

Explanation: Geotropism refers to the growth movement of roots towards gravity (downwards) and stems against it (upwards).

 

Q38. Why is the concept of life span important in defining living organisms?

a) It shows how organisms reproduce.

b) It represents the ability to grow.

c) It indicates the beginning and end of life.

d) It explains their ability to move.

 

Answer: c) It indicates the beginning and end of life.

Explanation: Life span refers to the complete cycle of life from birth to death in living organisms.

 

Q39. What is hibernation in animals?

a) A type of reproduction

b) A long period of activity during summer

c) A state of inactivity during winter

d) The process of food storage

 

Answer: c) A state of inactivity during winter

Explanation: Hibernation is a state of dormancy in animals during winter to conserve energy when food is scarce.

 

Q40. What is aestivation in animals?

a) A type of movement

b) A response to stimuli

c) A state of inactivity during summer

d) A mode of reproduction

 

Answer: c) A state of inactivity during summer

Explanation: Aestivation is a period of dormancy in animals during hot and dry summer conditions.