Answer:
semi-permeable
Explanation:
passive transport is the movement of substances along the concentration gradient and no energy is utilized in it
The signal transduction pathways<span> recruited by the receptors of these hormones and growth factors </span>are<span> of particular interest.
Im not too sure about this might wanna check it.</span>
Answer: It would us valine
Explanation:
Organ
The heart is a muscular organ that is part of the circulatory system.