The Sound Following the flash of lighting is because of Thunder.

Lightning is seen earlier than thunder because light travels much faster than sound.

The roar of thunder is the result of a shock wave produced when lightning super-heats the air through which it passes, causing that air to expand very rapidly. This rapid expansion of air creates a shock wave that travels outward at close to the speed of sound.

Ichthyology is the branch of biology devoted to the study of fish.

It is also known as Fish science which includes bony fishes (Osteichthyes), cartilaginous fish (Chondrichthyes), and jawless fish (Agnatha).

Pollination by wind is called Anemophily or Wind pollination. The process of the transfer of pollen from one individual plant to another, whereby the pollen is carried by air currents is called Anemophily.

Almost all gymnosperms (Non-flowering plants) are anemophilous, as are many plants in the order Poales, including grasses, sedges and rushes.

An electrically charged atom or group of atoms formed by the loss or gain of one or more electrons is called an Ion.

Cation:

An ion is a cation (positive ion) if it is created by electron loss and is attracted to the cathode in electrolysis.

Anion:

An ion is an anion (negative ion) if it is created by an electron gain and is attracted to the anode.

The valence of an ion is equal to the number of electrons lost or gained and is indicated by a plus sign for cations and a minus sign for anions.

Ex: Na +, Cl−, Ca ++,...

Breeding and management of bees is called Apiculture.

A beekeeper or apiarist keeps bees in order to collect their honey and other products that the hive produces (including beeswax, propolis, flower pollen, bee pollen, and royal jelly), to pollinate crops, or to produce bees for sale to other beekeepers.

A location where bees are kept is called an 'apiary' or 'bee yard.'

The myofibrils are composed of actin and myosin filaments, repeated in units called sarcomeres, which are the basic functional units of the skeletal muscle.

Points that lie on the same line are called Collinear points. And that points lie on the same plane are called Coplanar points. 

The distance around a circle is called as Circumference. And that in the case of square or rectangle it is called as Perimeter.