In secondary succession, the pioneer species are plants that are adapted to exploit disturbances rather than bare rock. They typically include plants such as grasses, birch trees, and fireweed. Organic matter from the pioneer species improves the soil so other trees and plants can move into the area.
<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>
In a food web there is a hierarchy, if any one of the parts of a food web is changed it can effect the parts above that may consume it, or the parts below that it may consume. Since the food web relies on balance and a hierarchy, if something changes it could disrupt the balance and flow of energy in the food web.
Explanation:
Risks:
may lead to a lack of variety in plant or animal species
The nutritional value of foods can be less
Benefits:
faster than natural selection
More selective breeds / Types