Questions

A scientific theory is a well-substantiated explanation of some aspect of the natural world, based on a body of facts that have been repeatedly confirmed through observation and experiment. Such fact-supported theories are not "guesses" but reliable accounts of the real world. Scientific theories are not ever proved in the sense of being proved to be 100% correct.

Examples of some scientific theories are ::

Evolution, gravity, atomic theory, the germ theory of disease, relativity, quantum theory, electromagnetic theory, layered Earth theory, etc...

A DVD is an example of Optical Disc.

World Town Planning Day (WTPD) also known as World Urbanism Day is celebrated on 8 November.

Kunchikal falls of India is of height 1493 ft is in Karnataka state of the river Varahi.

Mutations are accidents in the copying of DNA. A genetic mutation is a random change in the DNA that is passed on further generations of cells and or organisms. 

Genetic mutations are accidental changes in the DNA in the germ cells or early in the formation of the embryo. These changes if they are in the germ cell will be passed on to other organisms formed by sexual reproduction or asexual reproduction. An example would be the golden delicious apple. A lost of genetic information due to a mutation resulted in a different color of fruit.

Genetic mutations that cause diseases are not always passed on to offspring.