A minute pore which helps in exchange of gases is:

A minute pore which helps in exchange of gases is called a stoma or stomata. It is an opening on a plant's surface from which it can absorb carbon dioxide from the atmosphere and release oxygen. The stomata are also important for regulating water vapor and temperature. The stoma is composed of two guard cells that form the opening. When the guard cells swell up with water, the opening gets wider and allows for exchange of gases. When the guard cells are less turgid, the opening gets narrower and less gas exchange takes place.