Questions

They both are used to replace characters in a string

The first talkie film in India was Ardeshir Irani released Alam Ara, on 14 March 1931.

Irani later produced the first south Indian talkie film Kalidas directed by H.M. Reddy released on 31 October 1931.

One of two sublayers of the data link layer of OSI reference model, as defined by the IEEE 802 standard. This sublayer is responsible for maintaining the link between computers when they are sending data across the physical network connection

The best example for somatic mutation would be cancer, familial cancer (which transmits through gametes to the next generation) are not so common while sporadic cancer is seen the most where body cells of a particular area goes through mutations for a number of years and becomes cancerous, but it is not transmitted to next generation.

The troposphere is the lowest layer of the Earth's atmosphere. The air is very well mixed and the temperature decreases with altitude. Air in the troposphere is heated from the ground up. The surface of the Earth absorbs energy and heats up faster than the air does.