Freshwater fish used as food in many parts of the world.
Water turbines convert the kinetic energy of water into electric current.
Synovial joints can be categorised by the direction of movement they allow.
Surface epithelia cover the external and internal surfaces of the body
An introduction to the relief and hydrography of China.
Cyclones are large areas of circulating air with clouds and precipitation being formed in its centre.
Cold and warm fronts are formed where bodies of cold and warm air meet.
Groundwater and aquifers are types of underground waters.
A periodic climate pattern that occurs across the tropical Pacific Ocean every five years.
The Crow are Native Americans who inhabited the Yellowstone River valley.
This animation demonstrates the anatomy of birds through the example of mallards.
The United States entered World War II after the devastating attack by the Japanese navy.
Division of space by three intersecting planes in several different arrangements.
Triglycerides containing unsaturated fatty acids are liquid at room temperature.
One of the most important monocot crops.
The reflex triggered by the stretching of the thigh extensor muscle is the patellar reflex.
The reproductive system is a series of organs working together for the purpose of reproduction.
Types of bridges include beam-, arch-, suspension-, cantilever and truss bridges.
Three saturated fatty acid molecules linked to a glycerol molecule.
The most ancient group of animals, they live underwater, lack real tissues and body symmetry.