A diagnostic test for tuberculosis (TB) involves injecting antigen (from the bacterium that causes TB) under the skin and then waiting a few days for a reaction to appear. This test is NOT useful for diagnosing TB in AIDS patients. Explain why

This test is called TB Skin Test.

Some people who are infected with both HIV and TB bacteria will not react to the TB skin test. This is because the immune system is not working properly. Anyone who is HIV infected and has a negative skin test should also have other medical tests, if they have symptoms of TB disease.

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.

coal is not sustainable because it will one day run out.