10. Which of these statements is correct about the circulatory system? It transports hormones
Capillaries have thicker walls than veins Systemic circulation carries blood to and from the lungs
All are true ​

Six amino acids have side chains that are polar but not charged. these are serine (ser), threonine (thr), cysteine (cys), asparagine (asn), glutamine (gln), and tyrosine (tyr). these amino acids are usually found at the surface of proteins, as discussed in the proteins 2 module.