Oxygen rich blood returns from the lungs to the heart. Which 2 systems are most directly involved in this process. Respiratory and circulatory
Excretory and digestive
Circulatory and excretory
Digestive and respiratory

Christie's doctor recommends that she eat 40 grams of protein a day. she's already consumed 50% of her protein recommendation for the day. how many servings of the given snack should christie have to meet her daily protein recommendation?

What do all macromolecules have in common with each other? oa. they all are formed from the same elements.ob. they all have major roles in cell membranesoc. they all act as catalysts in the body.od. they all have peptide bonds between carbon atoms.

Nucleic acid certain protein cell membranes certain carbohydrates