Some traits such as earlobe attachment, blood type, and the presence or absence of dimples, have limited variation throughout hu
man population because they are controlled by a single cell other traits such as skin color and han height are widely variable throughout the human population because
Traits such as skin color and height are variable throughout the human population because these traits are controlled by more than one cell. The cells don't perform at the same rate and don't produce the same biomolecules. Therefore, the maximum height of a person is not achieved which results to variations.
the first answer as blood needs to be oxygenated to be passes round the body then when its deoxgenated it will return to the heart to be pumped around the body again
