Chapter 1 - The Living World : Adaptations and Classification
1. Find my match !
‘A’ Group
(1) Lotus
(2) Aloe
(3) Cuscuta
(4) Venus flytrap
‘B’ Group
(a) flower and leaves attract insects
(b) Haustorial roots for absorption of food
(c) Adapted to live in deserts
(d) Adapted to live in water
Ans:
‘A’ Group
(1) Lotus
(2) Aloe
(3) Cuscuta
(4) Venus flytrap
‘B’ Group
(d) Adapted to live in water
(c) Adapted to live in deserts
(b) Haustorial roots for absorption of food
(a) flower and leaves attract insects
2. Read the paragraph and answer the following questions.
I am a penguin. I live in a polar region covered by snow. My abdomen is white. My skin is thick with a layer of fat underneath. My body is spindle-shaped. My wings are small. My toes are webbed. We live in flocks.
(a) Why is my skin white and thick and why is there a thick layer of fat underneath?
Ans: Penguins live in extremely cold Polar regions. The region is always covered with ice. It has thick skin with a thick layer of fat underneath because it does not allow the body’s heat to escape. Due to its white color, it can mix with the surroundings and cannot be easily located. This way, it seeks protection against predators.
(b) Why do we live in flocks sticking close to each other?
Ans: By staying in a flock, one is protected against attacks from predators. It becomes easier for parental care. Also, by sticking to each other, the body heat is not lost to the surroundings.
(c) Which geographical region do you inhabit? Why?
Ans: Penguins stay in the polar regions, especially in the Antarctic region. There is abundant food available for the penguins, and thus they are seen here.
(d) Which adaptations should you have to enable you to live permanently in the polar region? Why?
Ans: In order to permanently inhabit the polar region, the body should be adapted to cold temperatures. There should be a thick layer of fat and thick skin to protect the body. The ability to regulate body temperature should be extremely important for survival.
3. Who is lying?
(a) Cockroach – I have five legs.
Ans: Cockroach is lying. Cockroach has six legs.
(b) Hen – My toes are webbed.
Ans: Hen is lying. Its toes are not webbed.
(c) Cactus – My fleshy, green part is a leaf.
Ans: Cactus is lying. Its fleshy and green part is a stem.
4. Read each of the following statements. Write a paragraph about adaptation with reference to each statement.
(a) There is extreme heat in deserts.
Ans: The living organisms residing in the extreme heat of deserts show appropriate adaptations in their body structure and their life processes. Camels show many adaptations, like modified legs, eyes, nose, and the hump on the back. Rats, snakes, spiders, and lizards escape the heat of the sun by remaining inside deep burrows during the daytime. Plants, like different species of cacti, have specially modified body structures with which they can survive in extreme heat.
(b) Grasslands are lush green.
Ans: The availability of water is ample in grasslands. Therefore, there is plenty of grass and shrubs. The fibrous roots of grasses hold soil particles and prevent soil erosion. In equatorial regions, there is lush green growth due to sunlight and an abundance of water. Due to plant cover on all sides, the grasslands look lush green.
(c) Insects are found in large numbers.
Ans: Insects adapt to any kind of habitat. Some insects can fly. They have adaptations like light bodies and two pairs of wings, which help them fly. Some insects are also aquatic; some stay near water bodies. Some are in deserts too. Many have the ability to camouflage with their environment, thus escaping the attention of predators. They can reproduce in large numbers. Due to all such adaptations, insects are found in large numbers.
(d) We hide.
Ans: Some of those are weak organisms. In order to seek protection from enemies, they hide in their habitats. The coloration of their bodies mixes with the surroundings, and thus enemies do not see these hiding creatures. Some of them also hide to catch prey. Chameleons and garden lizards can change color rapidly and become unnoticeable. This helps them catch their prey easily.
(e) We have long ears.
Ans: Long ears are seen in herbivores. They have to be alert to the attack of predatory carnivores. They can move their ears to locate the approaching prey. In such danger, they run away in a herd. Having long ears is an adaptation to escape from enemies.
5. Answer the following.
(a) Why is the camel called the ‘Ship of the desert’?
Ans:
(i) Camels have long legs with flat and cushioned soles.
(ii) This type of leg helps camels move across the desert easily.
(iii) Camels have thick skin, which prevents the loss of water from the body.
(iv) The nostrils are protected by folds of skin, and the eyelashes are long and thick to prevent the entry of fine dust particles into the nose and eyes.
(v) Due to these adaptations, camels not only survive the scarcity of water but can also be used for transportation.
(vi) Therefore, the camel is called the ‘Ship of the Desert’.
(b) How can plants like cactus and acacia live in deserts with scarce water?
Ans:
(i) The leaves of cactus and acacia are like small needles or modified into thorns. Therefore, they lose very little water by evaporation.
(ii) Stems perform photosynthesis in the absence of leaves and store water and food.
(iii) Stems also show the presence of a thick layer of waxy substance, which prevents the loss of water.
(iv) Also, their roots penetrate deep into the soil in search of water.
(v) Therefore, plants like cactus and acacia live in deserts with scarce water.
(c) What is the inter-relationship between adaptations of organisms and their surroundings?
Ans:
(i) Gradual changes occur in the body parts and also in the behavior of organisms, which help them adjust to their surroundings. Such changes are called adaptation.
(ii) Changes that take place in the various organs and life processes of organisms that enable them to live, feed, reproduce to perpetuate themselves, and protect themselves from their enemies in specific surroundings, depending upon the habitat and its geographical conditions.
(d) How are organisms classified?
Ans:
(i) There are large numbers of organisms on the earth. It becomes very difficult to study the characteristics of all these organisms without arranging them in a proper group.
(ii) In classification, scientific names are assigned to all organisms.
(iii) A scientific name consists of two parts: the first is a genus, and the second is a species.
(iv) A hierarchy is formed in the classification that starts with kingdoms, and further groups and sub-groups are formed depending upon basic similarities and differences.