☀️ Interdependence of Organisms

Primary 6 Science — Chapter 6 Notes with Answers
Created by Miss Clarissa Ng · www.clartutors.com
6.1 Energy from the Sun for Living Things

1. Organisms need energy to carry out their life processes.

2. The Sun is the primary source of energy on Earth.

3. A plant carries out photosynthesis in the presence of sunlight to make its own food.

The Sun — Primary Source of Energy on Earth
☀️ Light energy 🌱 Photosynthesis Light energy → Chemical potential energy Plants make their own food
Energy Transfer Between Organisms

4. The energy from the plant is then transferred to a plant eater which eats the plant.

5. An animal eater which eats the plant eater will obtain energy from the plant eater that it eats.

Energy Flow — From Sun Through a Food Chain
☀️ 🌿 Plant 🐛 Plant-eater 🦎 Meat-eater Energy transferred obtained
Food Relationships

6. The interaction between organisms in which one eats another is referred to as a food relationship. We show food relationships using food chains and food webs.

Food Chain vs Food Web — Showing Food Relationships
Food Chain 🌿 🐛 🐸 🐍 One path of energy flow Shows who eats whom in a line Food Web 🌿 🐛 🐰 🐸 🦊 Many interconnected food chains 🔗 Food relationships show how organisms depend on each other for energy Energy flows from the Sun → plants → plant-eaters → meat-eaters
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DID YOU KNOW?
Almost all energy on Earth comes from the Sun! Even fossil fuels like coal and oil are stored solar energy from plants that lived millions of years ago.
Food Chains and Food Webs

7. A food chain consists of a series of food relationships. The arrow denotes 'is eaten by'.

Food Chain — Arrow means "is eaten by"
🌿 Plant 🦌 Plant-eater 🦁 Meat-eater Example: plant → deer → lion

8. A food web is formed when a number of food chains are interconnected.

Food Web — Multiple interconnected food chains
🍃 Leaves 🦌 Deer 🦓 Zebra 🦁 Lion Food web
6.2 Roles of Organisms in Food Chains and Food Webs

1. Organisms that make their own food are known as food producers. These are usually the plants.

2. Organisms that obtain their food from other organisms are known as food consumers. These are usually animals.

3. In a food chain, primary consumers are organisms that eat food producers.

Producers and Consumers in a Food Chain
Producers 🌿 Make their own food (usually plants) Consumers 🐛 Obtain food from other organisms (animals)

4. Secondary consumers are the organisms that eat the primary consumers.

5. Tertiary consumers are organisms that eat the secondary consumers.

Levels of Consumers in a Food Chain
🌿 Producer 🐛 Primary Consumer 🐸 Secondary Consumer 🐍 Tertiary Consumer eats producers eats primary eats secondary

6. Animals that eat only plants are called herbivores.

7. Animals that eat only other animals are called carnivores.

8. Animals that eat both plants and other animals are called omnivores.

Types of Consumers by Diet
Herbivores 🦌 Eat only plants Carnivores 🦁 Eat only animals Omnivores 🐻 Eat both plants & animals
Predators and Prey

9. A predator is an animal which hunts and kills other animals to eat. Examples: Eagles, snakes, sharks, tigers and lions.

10. The animal that is hunted down and eaten is the prey. Examples: Rabbits, deer, cows and small fish.

Predator-Prey Relationship
Prey 🐰 Hunted and eaten by predator Predator 🦅 Hunts and kills other animals

11. The predator-prey relationship is a feeding relationship.

📝 Chapter 6 Summary
Key Concepts to Remember
  • Organisms need energy to carry out life processes.
  • The Sun is the primary source of energy on Earth.
  • Plants carry out photosynthesis using sunlight to make food.
  • Energy transfers from plant → plant-eater → meat-eater.
  • The interaction where one organism eats another is a food relationship.
  • Food chains show a single path of energy flow (arrow = "is eaten by").
  • Food webs show many interconnected food chains.
  • Producers make their own food; consumers obtain food from others.
  • Consumer levels: primary → secondary → tertiary.
  • Herbivores eat plants, carnivores eat animals, omnivores eat both.
  • A predator hunts and kills; the prey is hunted and eaten.
Miss Clarissa Ng | www.clartutors.com
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