This exchange process occurs in the alveoli (air sacs) in the lungs. In fish and many invertebrates, respiration takes place through the gills. Other animals, such as insects, have respiratory systems with very simple anatomical features, and in amphibians even the skin plays a vital role in gas exchange.Plants also have respiratory systems but the directionality of gas exchange can be opposite to that in animals.ee also: Respiratory tract. The respiratory system (called also respiratory apparatus, ventilatory system) is a biological system consisting of specific organs and structures used for the process of respiration in an organism.
A robot is a machine designed to execute one or more tasks automatically with speed and precision. There are as many different types of robots as there are tasks for them to perform. Robots that resemble humans are known as androids; however, many robots aren't built on the human model. Industrial robots, for example, are often designed to perform repetitive tasks that aren't facilitated by a human-like construction. A robot can be remotely controlled by a human operator, sometimes from a great distance.
machine - any mechanical or electrical device that transmits or modifies energy to perform or assist in the performance of human tasks. 1  assembly - a group of machine parts that fit together to form a self-contained unit. 2  bagger - a machine for putting objects or substances into bags.