<span>Three anatomical features that birds share with their theropod ancestors are:
</span><span>1. they had light, hollow bones
</span>2. they rearranged hip and leg muscles because this of <span>improved bipedal movement
</span>3. they had their flight oriented with the use of wings for balance
<span>Electrical signals in the body are often based on ions because ions are charged particles</span>
Lactic acid is the result of fermentation. Fermentation is when there is a lack of oxygen but youre body is still trying to get you enough ATP molecules (energy) to function. It is the stuff that makes you sore lol
It is the repiratory and the circulatory