A virus structure can be on of the following: icosahedral, enveloped, complex and helical. These viruses can appear to in a shape but a closer, more steady look reveals that they are actually icosahedral.
When it triggers an abnormal or vigorous immune responce, treating the antigen that would normally cause no threat as something harmful.
Answer:
The correct answer is option C.
Explanation:
The human gastrointestinal microbiota or the gut microbiota or the gut flora refers to the microbes, which thrive in the digestive tracts of humans. The human gastrointestinal tract comprises the gathering of all the genomes of gut microbiota. It is the niche where the human microbiota is found.
The microbial composition of the gut microbiota differs across the digestive tract. In the small intestine and stomach, very small species of bacteria are found, while the colon comprises the densely populated microbial ecosystem. Of these over 99 percent of the bacteria found in the gut are anaerobes, as the space within the intestines is highly anaerobic.
These microbes are confined deep within the body where oxygen cannot reach as it is not supplied with the help of blood vessels. Thus, a highly anaerobic environment is witnessed deep within the intestinal regions.
