I think the Rotation of the earth provides a basis for our system of local time. The earth rotates on an imaginary axis at a rate of 15 degrees per hour. Meridians of longitude are the basis for time Zones. As Earth rotates different parts of Earth receive sunlight or darkness, giving us day and night. Having time Zones means that no matter where you live on the planets, your noon is the middle of the day when the sun is highest, while midnight is the middle of the night.
Why do organisms maintain fairly steady conditions within their cells and bodies? They must maintain stable conditions to keep their enzymes working and generally to enable the chemical reactions of life.
