I'm not entirely sure what you mean, but a fit animal is one that is able to out-compete with other animals in its ecosystem. It possesses some kind of advantage, which makes it easier to compete with others for food, water, shelter, and mates. Due to these qualities, the animal is obviously able to live for a good deal of time and have a greater chance of producing viable offspring.
Directly
Explanation:
The average kinetic energy of a gas particle is directly proportional to the temperature. An increase in temperature increases the speed in which the gas molecules move. All gases at a given temperature have the same average kinetic energy.
The sun's energy drives various processes on earth. One of these processes is photosynthesis in plants whereby light energy is converted into chemical energy by forming carbohydrates from carbon dioxide plus water, which is a process which usually gives off oxygen which animals need to breathe. Another process driven by the sun's energy could be evaporation of water into the air to form water vapour and clouds which then precipitate when cooled off over mountains so is involved in the water cycle.
I guess it should be hyperkinesia