Our Environment Blog 1

Our Environment

Important Instructions:

(i) Keep your text book open for reference.

(ii) Home Assignment need to be done in your Biology note book.

(iii) Complete your index, put chapter name and date when you start

(iv) All the intext exercises as well as exercise given at the end of the chapter have to be done.

Learning outcomes:

• define ecosystem and study its components
• classify ecosystem into various types on the basis of their nature and size
• develop the definition of a food chain

Introduction

Environment

• Includes all living and nonliving things.
• There need not be any necessary interaction between them.(unlike an ecosystem)

Ecosystem

• An ecosystem is a community of living organisms in conjunction with the nonliving components of their environment, interacting as a system.

Components of an ecosystem

•  The biotic components are all living organisms.
•  The non-biotic components are physical factors like air, water, soil, wind etc.

• 

Mode of nutrition in animals and plants

(done in earlier classes , just revisit the definitions)

Autotrophic and Heterotrophic - 

Saprophytes and Decomposers

Saprophytes are plants, fungi, and microorganisms that feed on the dead and decaying material.
Decomposers break down the organic matter or waste material and release nutrients into the soil.  For example, bacteria, worms, slugs, and snails.

Food Chain

The food chain consists of 

• producers, 
• consumers
• decomposers.

Green plants and algae that make food by photosynthesis are producers. 

Organisms that depend upon producers for their food, directly or indirectly are called consumers.

Microorganisms like bacteria and fungi that break down the complex organic substances in dead plant and animal into simple inorganic substances are called decomposers.

The series of organisms that take part in transferring food energy from producers to consumers to decomposers is called a food chain. 

Home assignment:

Give and draw an example of a food chain.
Read the chapter further.