Tetrads may be defined as the stage of the division in which the cell contains the four spores in case of Ascus. The tetrad condition generally occurs in the meiosis division.
Tetrad stage are exceptionally found in the cocci or round bacteria. During tetrad stage, the bacteria divides in the square planar arrangement and forms the square of the four bacteria. This arrangement of four bacteria is the tetrad stage.
The answer is tropical areas. The tropical areas obtain more
radiant energy from the Sun than they lose to space through terrestrial
radiation, and vice versa for polar areas. Earth has an energy remaining in the
tropics and an energy scarcity for the polar areas.
