Veins carry blood the heart.
a. away from
b. towards
c. closer to
d. all of the above

hormones in blood stream

image: dtc.ucsf.edu

endocrine glands secrete hormones into the blood stream near them; the hormones then travel in our bloodstream until it reaches its destination, called a target cell, in distance parts of the body. in the target tissue, hormones lock onto the target’s plasma membrane, called the receptor site.

the three components of a nucleotide are the nitrogenous base, the phosphate group and the five-carbon sugar.