<span>A diseases may be classified as either communicable or non-communicable. Communicable diseases are caused by pathogens who inhabit a host, man (I'm not saying man is the only host or man is necessarily the final host; there could be many host) who in turn passes the disease to another. Pathogens are viral, bacterial, parasitic and fungal. There are several stages before the pathogen metamorphoses into a full-blown disease. The stages in which several events happen builds up before the pathogen affects the final host is called a communicable disease chain. There are six stages ( Pathogen, reservoir, portal of ext, mode of transmission, portal of entry and susceptible host) in the communicable disease chain but the step a nurse shouod take is
1. Destroy the second link (Reservoir) by thoroughly sanitizing the environment. Obviously, this is where the Pathogens live. If the reservoir is taken care of; there's no way they could infect the host.</span>
Answer: C
Explanation:
For example, in trp-operon, an abundance of tryptophan. coli inhibits the expression trp-operon genes.
Trp operon is a negative repressible feedback mechanism
trpR gene is expressed continually at a low level
nebular hypothesis
The most widely accepted theory of planetary formation, known as the nebular hypothesis, maintains that 4.6 billion years ago, the Solar System formed from the gravitational collapse of a giant molecular cloud which was light years across. Several stars, including the Sun, formed within the collapsing cloud.
<span>Genetic variation will increase because of a new habitat and food source.</span>