Soil moisture. Soil moisture affects the soil biota in two ways. Biologically water is essential for life and for enzyme activity and metabolism and, is a solvent for biological nutrients and other chemicals. Physically, soil moisture affects soil temperature (water is good conductor of heat) and soil aeration.oil moisture. Soil moisture affects the soil biota in two ways. Biologically water is essential for life and for enzyme activity and metabolism and, is a solvent for biological nutrients and other chemicals. Physically, soil moisture affects soil temperature (water is good conductor of heat) and soil aeration.
Your blood is actually always red! Blood in your veins has very little oxygen and is a dark red color that looks almost blue when covered by your skin. Your arteries have bright red blood because it has a lot of oxygen in it that is being carried throughout your body to be used by tissues.
1 Most veins carry deoxygenated blood, which is a darker color than oxygenated blood. The deep color of blood makes veins appear dark, too. 2  Different sizes of vessels appear different colors.  If you look closely at your veins, for example, along the inside of your wrist, you'll see your veins are not all the same color.