Science form 2

1. Chapter 2 Ecosystem
SCIENCE | DLP | FORM 2

2. 2.1 Energy Flow in an
Ecosystem

3. Do you know?
• Sun – the source of energy in all ecosystems
• Green plants – convert light energy from the Sun into
chemical energy through photosynthesis.
• Chemical energy – transferred to primary consumers
followed by secondary and tertiary consumers in the
food chain and food web

4. Ecosystem
Organisms
Producer
Consumer
Decomposer

5. Ecosystem
Organisms
Producer
Consumer
Decomposer
• Produces its own food through
photosynthesis
• Green plants

6. Ecosystem
Organisms
Producer
Consumer
Decomposer
• Eat another organism
• Eat producers
• Herbivores and omnivores
• Eat secondary consumer
• Carnivore
• Eat primary consumer
• Omnivore and carnivore
Primary Consumer
Secondary Consumer
Tertiary Consumer
• Herbivore – plants
• Carnivore – animals
• Omnivore - both

7. Ecosystem
Organisms
Producer
Consumer
Decomposer
• Breaks down dead animals
and plants into simpler
materials or nutrients
• Saprophytism

8. Ecosystem
DEAD
Producer
Primary
Consumer
Secondary
Consumer
Tertiary
Consumer
Decomposer

9. Food Chain
Used to show the feeding relationship between organisms
Cabbage Snail Bird Fox
Producer Primary
consumer
Secondary
consumer
Tertiary
consumer

10. Food Web
The interconnection of a few food chains
Cabbage  Caterpillar  Bird  Snake
Cabbage  Snail  Bird  Snake
Cabbage  Grasshopper  Bird  Snake
Cabbage  Grasshopper  Frog  Snake

11. Energy Flow in Food Web
Cabbage Snail Bird Fox
Energy is transferred from one organism to another organism

12. Energy Flow in Food Web
•Energy loss
• Movement
• Respiration
• Heat energy / chemical energy through undigested food /
faeces

13. See you
in the next
video …