THE LIVING ORGANISMS AND THEIR SURROUNDINGS

 NOTES

Organisms

An organism is simply defined as any living thing, ranging from microscopic bacteria to large elephants and everything in between.

Characteristics of Living Organisms

• Plants are living things, but they do not appear to move like a dog or a pigeon.
• On the other hand, a car or a bus can move, yet we consider them as non-living.
• So there are certain characteristics that differentiate living from nonliving-

1. Living beings are made of cells.
2. Living beings obtain and use energy.
3. Living beings grow and develop.
4. Living beings reproduce.
5. Living beings adapt to their environment
6. Living beings respond to their environment or stimuli

Adaptation

The presence of specific features or certain habits, which enable a plant or an animal to live in its surroundings, is called adaptation.

Surroundings

• The different surroundings or areas have different organisms that live in.
• E.g.: The deserts have camels, the mountains have goats and yak.

Habitat

The surrounding where living organisms survive is known as habitat.

• The organisms depend on their habitat for their food, water, air, shelter and other needs.
• Habitat means a dwelling place (a home).
• Several kinds of plants and animals may share the same habitat.

Biotic Components

• The living components of a habitat are called biotic components.
• Eg: plants, animals

Abiotic Components

• The non-living components of a habitat are called as abiotic components.
• E.g.: rocks, soil, air, water etc

Terrestrial Habitats

• The plants and animals that live on land are said to live in terrestrial habitats.
• E.g.: forests, grasslands, deserts, coastal and mountain regions.

Aquatic Habitats

• The habitats of plants and animals that live in water are called aquatic habitats.
• E.g.: ponds, swamps, lakes, rivers and oceans.

Aquatic habitats could be fresh water (river, pond) or marine (sea) or even estuarine (delta of river meeting with the sea)

QUESTION AND ANSWERS

1. What is a habitat?
Ans: The surroundings where animals live is called their habitat. The organisms depend on their habitat for their food, water, air, shelter and other needs. Habitat means a dwelling place.

2. How are cactus adapted to survive in a desert?
Ans: Cactus are adapted to survive in a desert as they have
(i) No leaves or spiny leaves to prevent water loss through transpiration.
(ii) Stem is modified in such a way that it performs photosynthesis and conserves water.
(iii) Their roots go very deep into the soil for absorbing water.

3. Fill in the blanks:
(a) The presence of specific features which enables a plant or an animal to live in a particular habitat is called___________ .
(b) The habitats of the plants and animals that live on land are called _________________ habitats.
(c)The habitats of plants and animals that live in water are called ____________________ habitats.
(d) Soil, water and air are the____________ factors of a habitats.
(e) Changes in our surroundings that make us respond to them are called
Ans: 
(a) adaptation
(b) terrestrial
(c) aquatic
(d) abiotic
(e) stimuli

4. Which of the things in the following list are non-living?
Ans: Plough, Mushrooms, Sewing machine, Radio, Boat, Water, Hyacinth, Earthworm. Plough, Sewing machine, Radio, Boat and water are non-living.

5. Give an example of a non-living thing which shows any two characteristics of living thing.
Ans: Example of non-living thing is cloud which shows following two characteristics of living things:
(i) It grows in size
(ii) It shows movement.

6. Which of the following non-living things were once part of a living thing?
Butter, Leather, Soil, Wool, Electric Bulb, Cooking Oil, Salt, Apple, Rubber.
Ans: Butter, Leather, Wool, Cooking oil, Apple and Rubber are the non-living things which were once part of a living thing.