As the moon moves eastward around 13 to 15 degrees per day in the sky in its orbit about the earth (there are 360 degrees around the whole sky for it to complete its orbit in 27.3 days), it moves with respect to the background stars noticeably each day, causing it to rise nearly an hour later each day/night when compared to the previous day/night.
Pathogenicity vs. Virulence. Pathogenicity refers to the ability of an organism to cause disease (ie, harm the host). This ability represents a genetic component of the pathogen and the overt damage done to the host is a property of the host-pathogen interactions. Commensals and opportunistic pathogens lack this inherent ability to cause disease.
A unicellular organism, also known as a single-celled organism, is an organism that consists of only one cell, unlike a multicellular organism that consists of more than one cell. Historically, the simple single celled organisms have sometimes been referred to as monads, specially the unicellular flagellates. The main groups of unicellular organisms are bacteria, archaea, protozoa, unicellular algae, and unicellular fungi.