THE ENVIRONMENT

Subject: Geography

 Class:      SS1

Topic: The environment

Specific Objectives: By the end of this lesson the students should be able to;

1. Define the environment
2. State the types of environment
3. Describe the components of the environment
4. Mention the domains in the environment
5. Identify the examples of types of environment in their area.

                             THE ENVIRONMENT

The Environment can be defined as the total surrounding of an organism in a given area including the physical surrounding, cultural, social and economic factors surrounding an organism.

                            TYPES OF ENVIRONMENT

1. Physical environment – This include things in the environment which can be felt, touched or seen. They include physical materials such as chairs, tables, houses, vehicles, electronics, trees, tables, soils, rocks etc. All these can be felt and touched.
2. Social environment – This include the ways through which people interact in the environment, our friends and relations, social group, quality of life in the environment, schools, churches etc.
3. Cultural environment – This means the way of life of a people in an area. These include, the people’s language, mode of dressing, ceremonies etc. It also includes acceptable norms, beliefs, value systems, mode of worship etc. All these make up the cultural environment. However, the cultural environment differs from place to place.   

                COMPONENTS OF THE ENVIRONMENT

There are two major components of the environment. These are;

1. Biotic Components (Living Components) – The biotic components include the living things (plants and animals) which can be grouped into producers, consumers and decomposers

1. Producers: Producers are autotrophs (green plants and some micro-organisms) which can manufacture their own food from simple inorganic materials during the process of photosynthesis and chemosynthesis.
2. Consumers: Consumers are the heterotrophs (animals and some plants) which cannot manufacture their own food. They may be primary, secondary or tertiary consumers.
3. Decomposers: Decomposers are bacteria and some fungi which break down dead plants and animals in order to feed on them and in the process, nutrients are released to the soil for use by the producers.

2. Abiotic Components: The abiotic component of an ecosystem are the non-living things which include;

1. Climatic factors like temperature, wind humidity, sunlight and rainfall.
2. Inorganic materials and nutrients such as carbon (iv) oxide, oxygen, nitrogen, calcium and phosphorus.
3. Edaphic factors like soils, rocks and topography
4. Other factors like dust, storm, fire and water

INTERACTIONS AMONG COMPONENTS OF ECOSYSTEM

There is a unique interaction among the various components of an ecosystem. Green plants use carbon (iv) oxide, water and chlorophyll in the presence of sunlight to produce carbohydrate or starch. Animals feed on these carbohydrates or plants and release carbon (iv) oxide for plants to take in. Micro-organisms and other decomposers break down dead plants and other organisms to release nutrients to the soil. These nutrients are absorbed by plants for use in food production. Plants give out oxygen during photosynthesis which is used by animals for their normal respiration.

DOMAINS OF THE ENVIRONMENT

1. Lithosphere-:

Characteristics of Lithosphere;

1. The Lithosphere is the solid portion of the earth
2. It is the outermost layer or zone of the earth crust
3. It is made up of rocks and mineral materials
4. It represents 30% of the earth surface
5. The outermost layer of the land mass is made up of loose rock materials like gravel, sand and soil.

2. Hydrosphere-:

Characteristics of the Hydrosphere;

1. The hydrosphere is the liquid portion of the earth
2. It covers about 70% of the earth’s crust
3. It holds water in various forms, solid, e.g. ice, liquid like water and as gases e.g. water vapour
4. It includes all forms of fresh water like lakes, river, water vapour
5. It also includes ocean water which is salty
6. Ocean water accounts for about 97% of the hydrosphere

3. Atmosphere-:

Characteristics of the Atmosphere;

1. The atmosphere is the gaseous portion of the earth
2. It is a layer of gases surrounding the earth
3. Over 99% lies within 30 km of the earth’s surface
4. Its density decreases progressively with elevation
5. It contains water in form of water vapour in lower layers
6. Weather phenomenon such as cloud, rain and snow are largely confined in the atmosphere
7. It contains 78% Nitrogen, 21% Oxygen, 0.03% Carbon dioxide and 0.97% rare or inert gases.

4. Biosphere-:

Characteristics of Biosphere;

1. The biosphere is the zone of the earth occupied by living organisms
2. It is a layer of life which exists on earth’s surface and the lithosphere
3. It has a maximum thickness of only a few kilometres
4. It is a narrow zone where complex biological and chemical activities occur
5. It includes organisms like plants, animals and micro-organisms.

EVALUATION:

1. Define the environment
2. State two characteristic each of any two domains of the environment
3. Briefly explain Abiotic component of an ecosystem

ASSIGNMENT:

1. Mention any five examples of the physical environment in your homes
2. Briefly explain how the components of the environment interact
3. Write short notes on; decomposers, consumers and producers.