The stage of cellular respiration
transport chain takes place in the part of the above illustration labeled with a 1.

The electron transport chain takes place in mitochondria.

Aerobic respiration is the main respiratory system of most of the animals. In humans, it is the exclusive respiratory system. There are three processes involved in aerobic respiration. They are glycolysis, Kreb's Cycle and electron transport chain. The glycolysis takes place in Cytoplasm, and the rest takes place in mitochondria. The Kreb's Cycle takes place in mitochondrial matrix, and the Electron Transport Chain takes place in inner mitochondrial membrane. In the inner mitochondrial membrane are embedded different electron carriers in form of complexes, which are complex 1a, 1b, 2, 3, and 4. Electrons get transported through these carriers and atlast gets accepted by oxygen.