Class 6 CBSE Science Notes

The Living Organisms and their Surroundings CBSE class 6 science notes

 The Living Organisms and their Surroundings

Living and Non-living Things

The study of living organisms is called biology.

Habitat and Adaptation
Habitat
The place where an organism lives is called its habitat.
Deserts, mountains, forests, grasslands, soil, ponds, lakes and rivers are some examples of habitats.
The habitat provides food, water, air, light, shelter and a place for breeding to plants and animals living in it.
Types of Habitat

Adaptation
The presence of specific body features which enable a plant or an animal to survive in a particular habitat is called adaptation.
Adaptation is of two kinds – structural adaptation and behavioral adaptation.
Structural adaptation refers to changes in the shape and size of the body of an animal. Examples: Ducks have webbed feet which enable them to wade through water easily.
Behavioral adaptation refers to changes shown by an animal with respect to its behavior. Examples: Penguins move in large groups to protect themselves from redactors.


Some Terrestrial Habitats
Deserts
A waterless area of land covered with sand and with little or no vegetation is called a desert.
It receives very low rainfall. The annual rainfall is less than 250 mm per year.
The maximum temperature in deserts ranges between 43.5°C and 49°C. The minimum temperature ranges between 0°C and 3°C.

Adaptations of Organisms Living in Deserts

Mountain Regions
A very high hill is called a mountain.
Mountains can be covered with snow.
Mountainous habitats are usually very cold and windy.

Adaptations of Organisms Living in Mountain Regions

Forests
A large area of land covered mainly with trees and plants is called a forest.

Adaptations of animals living in forests

Some Aquatic Habitats
Oceans
A very large area of sea is called an ocean.

The process of being accustomed to a different environment over short periods of time is called acclimatization.

 Important Questions
Multiple Choice Questions:
Question 1. Which one of the following statements is correct?
(a) Several kinds of plants and animals may share the same habitat.
(b) All the animals and plants in a habitat are adopted to it.
(c) Both the statements are correct.
(d) None of these is correct.
Question 2. Animals and plants have certain features which make them to survive in a particular habitat. This is called
(a) adaptation
(b) speciation
(c) specialization
(d) evolution
Question 3. Which is a biotic component of environment?
(a) Plants
(b) Animals
(c) Microorganisms
(d) All of these
Question 4. Which is not an abiotic component of environment?
(a) Soil
(b) Bacteria
(c) Water
(d) Air
Question 5. Which is an example of an animal found in mountain region?
(a) Leopard
(b) Yak
(c) Mountain goat
(d) All of these
Question 6. What are the characteristics of a desert plant?
(a) No leaves or very small leaves
(b) Spines
(c) Deep roots
(d) All of these
Question 7. Respiration in aquatic animals occurs by
(a) lungs
(b) gills
(c) nostrils
(d) legs
Question 8. Which is an aquatic adaptation?
(a) Streamlined body
(b) Light and hollow bones
(c) Hair on body
(d) Gills
Question 9. Bending of a stem towards sunlight is called
(a) geotropism
(b) phototropism
(c) hydrotropism
(d) nasticism
Question 10. Sunken stomata are present in
(a) hydrophytes
(b) epiphytes
(c) xerophytes
(d) mesophytes
Very Short Question:
1. Name some plants found on mountains.
2. What is habitat?
3. Name a few habitats.
4. Name two organisms that live in deserts.
5. Name a few plants that live in ponds.
6. Name the habitat where various types of fish live.
7. Name a common thing in all fishes.
8. What is the function of gill?
9. Name the animal which is called the ship of desert.
10. Name various types of habitat.
Short Questions:
1.What are the differences in the desert and sea regions?
2. What do you mean by term adaptation?
3. Explain the features offish which help it to adapt to live in water.
4. How are camels adapted to live in desert?
5. What do you mean by acclimatisation?
6. Why do we need abiotic factors?
7. How are some animals adapted to live in desert?
8. Write the features of desert plants.
Long Questions:
1.Explain the characteristics of living organisms.
2. Write the difference between living and non-living things.
Answer Key-
Multiple Choice Answers:
1. (c) Both the statements are correct.
2. (a) adaptation
3. (d) All of these
4. (b) Bacteria
5. (d) All of these
6. (d) All of these
7. (b) gills
8. (a) Streamlined body
9. (b) phototropism
10. (c) xerophytes
Very Short Answers:
1. Answer: Oaks, Pinus and Deodars.
2. Answer: The place where organisms live and which provide food and safety for them is called habitat.
3. Answer: Forests, grassland, mountains, ponds and oceans etc.
4. Answer:  Cactus, camel, desert rat.
5. Answer:  Hydrilla, lotus, hyacinth etc.
6. Answer:  Pond, river, sea.
7. Answer:  Gills, streamlined body, fins, tail.
8. Answer: Gills help the fish to absorb oxygen dissolved in water.
9. Answer: Camel
10. Answer:
(i) Terrestrial Habitats
(ii) Aquatic Habitats
(iii) Aerial Habitat

Short Answer:
1. Answer: In the sea, plants and animals are surrounded by salty water. Most of them use the air dissolved in water for breathing. In desert, a very little amount of water is available. It is very hot in the day time and very cold at night. The organisms breathe air from the surroundings.
2. Answer: The presence of specific features or certain habits which enable a plant or an animal to live in its surroundings is called adaptation.
3. Answer:
(i) The shape of the fish is streamlined which help in the movement.
(ii) The slippery scales/skin on their bodies to protect them.
(iii) They have flat fins and tails which help them to swim, change direction and to keep the body balanced.
(iv) They have gills which help in breathing in water.
4. Answer:
(i) The feet of the camels have thick, flat large soles which help them in the movement on sand.
(ii) They can live without water for a long time. When water is available, it drinks large amount of water at a time.
(iii) They release very little urine to prevent loss of water.
(iv) Their dung is also dry which also helps to prevent loss of water.
(v) The long legs of camel helps to keep the body away from the heat of the sand.
5. Answer: The small changes which take place in the body of a single organism over short periods to overcome small problems due to changes in the surroundings are called acclimatization.
6. Answer: The abiotic factors like air, water, light and heat are very important for the growth of plants. These abiotic factors are also very important for the growth and the development of animals.
7. Answer: Some animals like rats and snakes do not have the long legs like camels to stay away from the effect of heat during the day. They stay in burrows deep in the sand. They come out only during the night.
8. Answer: 
(i) The leaves in desert plants are either absent or very small.
(ii) Leaves are converted into spines which help to reduce loss of water.
(iii) The stems become thick, flat and green which help in photosynthesis.
(iv) The stem is covered with waxy layer which helps to retain water. In some plants stem is spongy and stores water.
(v) The roots go very deep in the soil to absorb water.
Long Answer:
1. Answer: There are following characteristics of living organisms
(i) All living organisms require food. The food gives energy for growth and to maintain other life processes.
(ii) All living organisms show growth. Young ones of animals grow into adults. Plants also grow.
(iii) All living organisms respire. In respiration oxygen is used for the oxidation of food and carbon dioxide is produced.
(iv) All living organisms respond to stimuli. All plants and animal respond to light, heat and the changes around them.
(v) All living organisms show excretion. The process of getting rid of waste product by the living organisms is called excretion. Plants also remove their wastes.
(vi) All living organisms reproduce. The process by which plants and animals produce their own kind is called reproduction.
2. Answer:

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