Apomixis is asexual reproduction without fertilization — developing or producing without sexual union. This is a botanical term (also known as apogomy) used with respect to many plants. Apomixis can occur in two ways: when the embryo arises from unfertilized egg produced without meiosis, called agamugenesis; a nucellar embryo is formed from surrounding nucellus tissues. The seeds produced are generally …

The apogee is the point at which a body is at its furthest orbit from the Earth. The opposite of the apogee, the point at which an orbiting body is nearest to the earth, is the perigee. Apogee is an Earth-specific term, and other terms exist for different celestial bodies. The apsis, for example, is a generic term used to …

The current geological epoch we live in is called Holocene, which began around 9600 BC. However, considering the way humans have altered the course of the Earth scientists suggest that the epoch be renamed anthropocene. Nobel-prize winning chemist Paul Crutzen coined this term in a casual remark in 2002, while talking about how the Earth was entering a new epoch …

The point of origin of an earthquake inside the Earth is called the focus, and the point on the surface directly above it is the epicenter. Severe earthquakes are usually shallow focus-that is, they occur within 60 km (37 miles) of the surface.

A colloidal system involving one liquid dispersed in another is known as emulsion. Any two immiscible liquids (those that cannot be mixed) can form an emulsion, like oil and water. An emulsifier is an agent that stabilizes the emulsion by lowering the interfacial tension between the constituents of the emulsion. Examples of emulsifiers are soaps, detergents and gelatine.

It is a device in the back of a “cathode ray tube” television or computer monitor (pre-plasma or LCD flat-panel). The electron gun fires a stream of electrons from the back of the TV onto the inside face of the screen, which is coated with a material that glows when hit by electrons. By using powerful magnets to direct the …

When a doctor takes a pulse he is feeling the patient’s heart-beat. If the heart is beating faster than normal it may be a sign like a rise in temperature of illness somewhere in the body. For signs of illness in the heart itself a more careful check is usually needed. The working of the heart is controlled by electrical …

An ecosystem is a biological environment consisting of all the organisms living in a particular area, as well as all the nonliving, physical components of the environment with which the organisms interact, such as air, soil, water and sunlight. It is all the organisms in a given area, along with the nonliving (abiotic) factors with which they interact; a biological …

An automatic car sounds as if it’s car that drives itself. In fact, it’s one in which the gears change automatically. The driver has to steer the car and operate the other controls such as the accelerator and brakes. The gear changes as the cars speeds up or slows down, and when it has to climb or descend a hill. …

The atomic pile is an early model of a nuclear reactor whose core consisted of layers of graphite blocks interspersed with uranium, designed to create a sustained fission reaction. The first atomic pile was created by Ernico Fermi and his colleagues at Columbia in 1942. It consisted of a stack of pure graphite bricks surrounding a neutron source. This first …