Results

Food webs are models that demonstrate how matter and energy is transferred between producers, consumers, and decomposers as the three groups interact within an ecosystem. Transfers of matter into and out of the physical environment occur at every level. Decomposers recycle nutrients from dead plant or animal matter back to the soil in terrestrial environments or to the water in aquatic environments. The atoms that make up the organisms in an ecosystem are cycled repeatedly between the living and nonliving parts of the ecosystem.

In this online lesson you will learn how to compare measurements that have different units.

In this unit you will learn how to convert between common metric units of measure.

By the end of this unit you will be able to:

• Use a ruler and protractor accurately
• Understand the SI system of measurement
• Convert between different units

This lesson explores appropriate units for metric measurement.

An online activity which will test your understanding of metric measurements.

This 32 minute long YouTube video investigates the water contamination problems in Tanzania, with specific focus on Dar Es Salaam. 

This 11 minute long YouTube video describes the various causes and types of water pollutants.

This YouTube video investigates what water pollution is and some examples and effects of water pollution.