Which of the following is an example of point-source pollution? a. fertilizer from agricultural runoff b. water from a sewage treatment plant c. salt from roads d. acid from abandoned mines

B. Water from a sewage treatment plant

Explanation:

Point source water pollution refers to contaminants that enter a waterway from a single, identifiable source, such as a pipe or ditch. Examples of sources in this category include discharges from a sewage treatment plant, a factory, or a city storm drain.

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.

answer; ///(b) it is composed of four protein chains and four heme groups;