The United States Geological Survey estimates that (as of 2005, the most recent year for which data is available) we withdraw 410 billion gallons of water a day, including both fresh and saline water. Most (80%) of these withdrawals go to thermoelectric power plants (for cooling) and agriculture (for watering crops).
Level 4 is the hair color level that is represented as dark brown. It is one of the most common natural hair colors and also very commonly found in hair dye. Level 4 is also common in red or...
Example 2: Human Hair Color. Brown hair color in humans is another example of a multi-allele trait, although human hair color is also a polygenic trait. You have probably noticed that the shades of hair are almost limitless, from palest blond to deep mahogany.