Different systems<span> of the body have different functions. For example, your </span>digestive system<span> is responsible for taking in & processing food, while your </span>respiratory system—working<span> with your</span>circulatory system<span>—is responsible for taking up oxygen and getting rid of carbon dioxide. Hope this helps</span>
Variation means difference in genetic makeup between individuals within a specie.
D) each parent passes only one factor for each trait to its offspring
<span>Above human figure, beyond are approximately 5 million of hair follicles. Men have approximately a rare 100,000 larger than ladies. Something varies greatly exceedingly, the characteristices of the female hair and the men are heavy, lengthy hair and so forth.</span>
