General Science Questions

A clade is a group of ancestral species and all its descendants. Hence it is a branch of one same species and so monophyletic.

The ozone gas present in the atmosphere absorb ultraviolet radiation. It is spread as a ozone layer throughout the stratosphere.

Collisions occur at curves because speed on the approach is too great.

A chemical reaction in which involves the absorption of heat from the environment is called a Endothermic reaction. 

Examples : Dissolving ammonium chloride in water, photosynthesis, melting ice cubes, mixing of potassium chloride with water,...

In the contrast, chemical reactions involving release of heat are known as exothermic reactions.

Examples : Combustion, coal is burnt, mix of CaO with water,...

Demography is the scientific study of Birth and death, The well being and the Growth of population. In brief, it is the study of human populations based on their size, composition and distribution across space – and the process through which populations change.

The purpose of defibrillation is to stop the chaotic, disorganized contraction of the cardiac cells. Defibrillation is a technique used in emergency medicine to terminate ventricular fibrillation or pulseless ventricular tachycardia. It uses an electrical shock to reset the electrical state of the heart so that it may beat to a rhythm controlled by its own natural pacemaker cells.