One of the old is rock for missions identified on earth is found on the shoreline of Hudson Bay in Canada. This rock forms 4.28 billion years ago. What information does the scientist need to most accurately determine the age of a rock?

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.