Chapter 4Interdependence among Living Organisms and the

Environment.

Interdependence among Living Organisms

Species: Have common characteristic that can produce fertile offspring

Population: A number of organisms of the same species living together

A community: Many populations living together in a particular place

The area where an organism lives and reproduces is its habitat. An ecosystem refers to the community of organisms living in the same habitat, together with the non living environment.

What is habitat and Ecosystem?

Interdependence of Living Organisms creates A balanced ecosystem

These different populations that live together are interdependent on one another for survival. Therefore, the interdependence among living organisms and the environment creates a balanced ecosystem.

Interaction between Living Organisms

Prey Predator:A relationship where an animal captures and eats other animals. For example, lion is a predator and

zebra is its prey.

Competition:Compete each other for food, light, water, shelter

mate or minerals.Consists of two types:

Intra-specific: The same speciesInter-specific: Different species

Symbiosis

Commensalism:-Relationship between two organism, in which oneorganism (the commensal)

benefits from the other

Mutualism:-Interaction that benefits both

Parasitism:-Parasites benefit by living in or on the host. The host would be harmed by the

parasites.

Food Web• What is producer, consumer and decomposer?

• Producer is green plants that produce foods, Consumer are usually the one that ate the producer and decomposers are organisms that break down dead animals.

Food Chain Food Web

Pyramid of Numbers• A diagram that shows the relative

number of organisms at each level of food

Level 4 (Tertiary Consumer)

Level 3 (Secondary Consumer)

Level 2 (Primary Consumer)

Level 1 (Producer)

There is a progressive decrease in number from a lower level to a higher level

Photosynthesis• Process in which green plants absorb solar energy to

make food from carbon dioxide and water

Requirements of Photosynthesis

• Plants need light, chlorophyll, water and carbon dioxide for photosynthesis.

Conservation and Preservation

• Conservation: Wise use of natural resources with the least disturbance of living things and their environment.

• Preservation: Measures or steps taken to maintain living things and the environment.

Conservation and Preservation of Living Organisms

Natural Resources management:-To protect our flora and fauna by setting up

animal sanctuaries, forests and wetland reserves.

Renewal of natural resources:-To restore damaged or destroyed habitats

due to logging, overfishing and mining.

Education:-To increase public awareness on the

importance of conservation and preservation of living organisms and their environment.

Legislation on wildlife protection:

-To control commercial hunting-To prevent overfishing

-To protect endangered species

Forest Management:-To minimise deforestation and

illegal logging-To prevent forest fires.

Pollution Control:-To minimise destruction of

habitat caused by pollution.

Role of Humans Maintaining the Balance of Nature

• Deforestation: when trees are cut down and forests cleared the natural habitats are destroyed.

• Land overuse by intensive farming: When farming is carried out intensively without practicing conservation

• Overfishing and overhunting: Extinction of certain species of animals.

• Industrialism: Combustion in cars, engines and factories causes air pollution and acid rain.

• Poor solid waste management: Rivers and lakes are often used as rubbish dumpsites.

Ways to Overcome• Legislation: Laws are made to stop activities that are harmful to the

environment. Any violation is punishable by law.

• Education: Helps people realize what their responsibilities to the environment.

• Pollution control: Reduction in pollution will reduce damage to the environment.

• Reusing or recycling: Make use of materials or recycled waste instead of throwing them away.

• Protecting habitats: Set up forests reserves and animals sanctuaries

• Restoring damaged or destroyed habitats: Convert them into recreation parks or botanical gardens.