Dysentery is caused as a result of bacterial infection caused by an unusual strain of E.coli. The E.coli is found normally in the intestine but during infection watery diarrhea along with mucous and blood is there.
Dysentery can also be caused by other infectious pathogens such as bacteria, parasites or viruses. The infection is caused when the pathogen enters the large intestine via mouth due to consumption of contaminated water or food, oral contact with the objects which are contaminated.
The treatment to the infection is through antibiotic drug.
During a dehydration reaction, two monomer molecules are covalently bonded to each other, with the loss of a water molecule. In this reaction, each monomer contributes part of the water molecule that is released during the reaction. This reaction is repeated as monomers are added to the chain one by one, making a polymer.
The correct answer to your question is the last one; how species change over time.
Hope that helps!
