A person with sickle-cell anaemia is
more prone to malaria
more prone to typhoid
less prone to malaria
less prone to typhoid
Certain pathogens are tissue/organ specific. Justify the statement with suitable example.
Certain pathogens are tissue/organ specific as they are adapted to overcome the resistance mechanisms of those tissues and organs, e.g., the pathogens that enter the gut must know a way of surviving in the stomach at low pH and resistant to various digestive enzymes.
The immune system of a person is suppressed. In the ELISA test, was found positive to a pathogen.
(a) Name the diseases the patient is suffering from.
(b) What is the causative organisms?
(c) Which cells of body are affected by the pathogen?
The immune system of a person is suppressed. In the ELISA test, he was found positive to a pathogen.
(a) The patient is suffering from AIDS.
(b) AIDS is caused by Human Immuno deficiency Virus (HIV). It is a retro virus containing RNA as genetic material.
(c) Macrophages and helper T-cells are affected by the pathogen.
$$ \text { Where are B-cells and T-cells formed? How do they differ from each other? } $$
Both type of lymphocytes and other cells of the immune system are produced in the bone marrow.
$B$ and $T$-cells are different from each other in the following aspects
| B-lymphocytes (B-cell) | T-lymphocytes (T-cell) |
|---|---|
| They mature in bone marrow. | They mature in thymus gland. |
| They produce antibody against antigen. | They directly attack the antigen or attach B-cells to produce antibody. |
| They do not respond to organ transplantation. | They respond to organ transplantation. |
| High fever, weakness stomach pain, loss of appetite and constipation | Typhoid |
Given below are the pairs of pathogens and the diseases caused by them. Which out of these is not a matching pair and why?
| (a) | Virus | Common cold |
|---|---|---|
| (b) | Salmonella | Typhoid |
| (c) | Microsporium | Filariasis |
| (d) | Plasmodium | Malaria |
Wuchereria species bancrofti and $W$ malayi), the filarial worms cause a slowly developing chronic inflammation of the organs in which they live for many years, usually the lymphatic vessels of the lower limbs and the disease is called elephantiasis or filariasis.
Fungi belonging to the genera Microsporium, Trichophyton and Epidermophyton are responsible for ringworms which is one of the most common infectious diseases in man.