Identify the correct statement regarding typhoid fever in human beings:
1. It is caused by a pathogenic protozoan Salmonella typhi
2. The pathogen remains confined to the small intestine
3. Widal test can confirm the infection very early in the disease
4. Intestinal perforation and death may occur in severe cases
A common cause of pneumonia in humans is:
Aedesaegypti is not a vector for:
The cannabinoids receptors are principally located in the central nervous system. The other location where they are present is:
Which of the following is not a documented effect of alcoholism?
Philadelphia chromosome is associated with:
Plants do not have cancers as:
HIV selectively infects and destroys:
The most common opportunistic infection associated with AIDS is:
The granulocytes that are actively phagocytic and the most numerous of the leukocytes circulating in the blood are the:
All of the following are true regarding inflammation EXCEPT:
Many physicians prefer mother's milk over cow's milk for infants. This is because mother's milk has the following property not found in cow's milk.
A plasma cell is a _____ cell that produces ______.
The epitope is
1. the part of the antibody that binds to the antigen.
2. the part of the antibody that binds to the T helper cell.
3. part of the antigen that is bound by the antibody.
4. part of the hypervariable region of the antibody.
What type of immunity is induced by the hepatitis B vaccine?
Besides helper T cells, what are two other types of cells that HIV infects?
When searching for a donor for an organ transplant, doctors try to match the __________ of the donor and recipient as closely as possible.
In a series of immune system experiments, the thymus glands were removed from baby mice. Which of the following would you predict as a likely result?
The antigen-binding sites of an antibody molecule are formed from the molecule's variable regions. Why are these regions described as variable?
Chemicals produced by virus-infected cells that alert neighboring cells to prepare a defense are called: