A type of large freshwater crayfish widespread in Europe.
The respiratory system is responsible for the intake of oxygen and the release of carbon dioxide.
This animation demonstrates the parts of the head, the torso and the limbs.
Christopher Columbus' three-masted carrack, the Santa Maria was the flagship of his first, landmark voyage.
This animation demonstrates Sir Isaac Newton's three laws of motion that laid the foundation for classical mechanics.
Wealthy citizens in ancient Rome owned large houses with varied layouts of several rooms.
The average house in Ancient Greece had a rectangular, geometrical floor plan and two stories.
Olfactory receptors produce electric signals when stimulated by odors.
The world famous monument in England still poses mysteries for archeologist.
The main parts of the human brain are the brain stem, the cerebellum, the diencephalon, and the cerebrum, which is divided into lobes.
Connective tissues include loose and dense connective tissues, adipose tissue, blood, tendon and bone tissue.
Taste receptors convert chemical stimuli into electric signals.
The heart is the central pump of the cardiovascular system beating several billion times over our lifetime.
Stratovolcanoes consist of layers of volcanic ash, debris and lava.
The Earth’s magnetic North and South poles are located near the geographic North and South poles.
The ozone layer filters the Sun´s harmful UV radiation, therefore it is indispensable for life on Earth.
Lightning is a sudden electrostatic discharge accompanied by a sound known as thunder.
Human activity increases the greenhouse effect and leads to global warming.
The step pyramid, built in the 27th century B.C., was the first pyramid in Egypt.
Nuclear power plants convert the energy released during nuclear fission into electric power.