Lesson Notes By Weeks and Term v5 - Grade 4

Lesson Video

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Performance objectives

• Describe a food chain and the flow of energy.
• Classify different sources of energy.
• Explain renewable vs. non-renewable resources.
• Describe the processes of heating and cooling.
• Identify simple machines in our environment.

Lesson summary

This week, we'll be revisiting and strengthening our understanding of key concepts we’ve learned in Natural Sciences and Technology in Grade

4. Revision is crucial because it helps us remember what we've learned, identify any gaps in our knowledge, and build a stronger foundation for future learning. Think of it like building a house – a strong foundation is essential for a sturdy and lasting home. Similarly, a solid understanding of these concepts will help you succeed in future science and technology topics. These topics are important in our everyday lives in South Africa.

Lesson notes

2.1 Food Chains A food chain shows how living things get their food. It starts with a producer, which is usually a plant. Plants make their own food using sunlight, water, and air (photosynthesis). Then comes a consumer, which eats the producer.

There are different types of consumers: Herbivores: Animals that eat only plants (e.g., cows, rabbits).

Carnivores: Animals that eat only other animals (e.g., lions, eagles).

Omnivores: Animals that eat both plants and animals (e.g., humans, chickens). Finally, there are decomposers, like fungi and bacteria, that break down dead plants and animals, returning nutrients to the soil. These nutrients help the producers grow, starting the cycle all over again. The arrows in a food chain show the flow of energy from one organism to another.

Example: Grass → Zebra → Lion → Decomposers In this example, the grass is the producer, the zebra is the herbivore (primary consumer), the lion is the carnivore (secondary consumer), and the decomposers break down the lion after it dies.

South African Context: Think about the African savanna. The grass feeds the wildebeest, which in turn feeds the lions. Vultures (scavengers, a type of consumer) may also eat the remains, and eventually, decomposers will break everything down. 2.2 Sources of Energy Energy is what makes things happen. We use energy every day to do almost everything.

There are different sources of energy: Sun: The sun is our main source of energy. Plants use sunlight for photosynthesis. Solar panels convert sunlight into electricity.

Wind: Wind turbines capture the wind's energy and convert it into electricity. Wind farms are common in coastal areas of South Africa.

Water: Water flowing through dams turns turbines to generate electricity (hydroelectric power). The Gariep Dam is a major hydroelectric dam in South Africa.

Coal: Coal is a fossil fuel that is burned to produce heat, which then generates electricity in power stations. South Africa relies heavily on coal for electricity generation.

Oil and Natural Gas: Like coal, these are fossil fuels. They are used for transportation (cars, airplanes) and to generate electricity.

Biomass: Organic matter, like wood and sugarcane waste, can be burned to produce heat and electricity.