Pregnant with her fourth child in a clinic in Benin, Rosine is relieved to learn that she does not have AIDS, after a free test considered a national health priority. “I was afraid the test...
Every cell in the human body holds about 20,000-25,000 genes, almost all of them in the nucleus – so-called nuclear DNA. But 37 others reside in tiny structures called mitochondria, which turn...
