The greenhouse effect select one: a. has made the earth the warm and cozy long before humans developed b. is unique to the planet earth c. never really varies in strength d. is a recent development resulting from the burning fossil fuels e. is mysterious and not understood

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.