A wide variety of optical instruments are in use today, ranging from microscopes to telescopes.
This animation demonstrates the structure and most important peripherals of desktop computers.
The pericarp of real fruits develops from the carpel, while the pericarp of pseudofruits develops from other parts of flowers.
Ports must provide necessary infrastructure and services for industry and marine transport.
Airports provide infrastructure and services necessary for aviation.
An ant colony consist of a queen, male ants and workers.
Honeybees produce a sweet and nutritious substance, honey.
Chlorophyll is a photosensitive green pigment found in plants; it absorbs light energy, thus plays a vital role in photosynthesis.
This animation demonstrates the main sources of air pollution: agriculture, industry and urban settlements.
The anatomy of annelids is demonstrated through the example of the common earthworm.
Moles are small subterranean mammals with modified, spade-like forelegs.
Glands of the endocrine system secrete hormones into the blood.
Surface epithelia cover the external and internal surfaces of the body
The zygote is the initial cell formed when two gamete cells are joined by means of sexual reproduction.
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.
The reflex triggered by the stretching of the thigh extensor muscle is the patellar reflex.
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.