Health, Common Diseases in Human & Immunity

1 Mark Questions

1. Why is secondary immune response more intense than the primary immune response in humans?[All India 2014]

Ans. Since, the secondary immune response is based on the memory of primary response,i.e. first encounter with antigen. The second generated immune response is more fast having higher affinity for antigen, and therefore more intense than primary immune response.

2. Name any two types of cells that act as 'cellular barriers' to provide innate immunity in humans.[Delhi 2014]

Ans. Certain type of leucocytes (such as PMNL- neutrophils, monocytes) and natural killer cells are two types of cells that act as 'cellular barriers' to provide innate immunity in humans

3. Name the two intermediate hosts on which the human liver fluke depends to complete its

life cycle so as to facilitate parasitisation of its primary host [Delhi 2014]

Ans. The human liver fluke requires two intermediate hosts, i.e. freshwater snail and fish to complete their life cycle and facilitate parasitisation of its primary host

1. How does haemozoin affect the human body when released in blood during malarial infection? [Foreign 2014]

Ans. The release of toxic haemozoin by the ruptured RBCs during malarial infection accounts for recurrence of high fever and chill every 3-4 days.

5. What is an autoimmune disease? Give an example. [Foreign 2014]

Ans. The abnormal response of an immune system in which it fails to recognise 'self and 'non- self' and start destroying its own cells and molecules is called autoimmune disease. Rheumatoid is an example of autoimmune disease which destroys articular cartilage and fusing bones

6. When does a human body elicit an anamnestic response? [All India 2013; Delhi 2011 C]

Ans. Second encounter of the organism with same antigen or pathogen elicits anamnestic or secondary response for which body have memory of first encounter.

1. State two different roles of spleen in the human body? [All India 2012]

Ans. The two roles of spleen in human body are:

1. Spleen acts as a filter to trap blood-borne microorganisms.
2. It is also a large reservoir of erythrocytes

8. How do interferons protect us? [All India 2012]

Ans. Interferons produced by virus-infected cells protects the non-infected cells from viral infection by inhibiting its replication and making cells resistant to viral infection

9. Why do pollen grains of some flower trigger sneezing in some people? [Foreign 2012]

Ans. Pollen grains are allergens and cause allergy in some people due to release of chemicals i ike histamine and serotonin from mast cells

1. What is it that prevent a child to suffer from a disease he/she is vaccinated against? Give one reason. [Delhi 2010]

Ans. Vaccination produce antibodies in large numbers, which protect the child by neutralising the pathogenic agents during infection. The vaccine also generate memory B and T-cells.

1. How does malaria differ from chikungunya with reference to their vectors? [All India 2010 C; Delhi 2008] Ans. Malaria is spread by the vector, i.e. Anopheles mosquite, whereas chikungunya is spread by the vector, i.e. Aedes
2. Malaria, typhoid, pneumonia and amoebiasis are some of the human infectious diseases. Which one of these are transmitted through mechanical carriers. [Foreign 2010] Ans. Amoebiasis is transmitted through mechanical carrier, i.e. houseflies
3. How does colostrum provide initial protection against disease to newborn infants? Give one reason.[Delhi 2009] Ans. Colostrum contains antibody IgA that provides protection against disease, thus protecting the newborn infants

1. Some allergens trigger sneezing and wheezing in human being. What causes this type of response by the body? [Delhi 2009]

Ans. Immune system of the body produce exaggerated response (allergy) against allergens and release chemicals like histamines and serotonin from mast cells. This is the cause of sneezing and wheezing, in response to these allergens.

1. Name the type of cells, the AIDS virus enters into after getting in the human body.

[All India 2009] Ans.AIDS virus enter into macrophages after getting in human body

1. Where are mucosal associated lymphoid tissues present in the human body and why? [All India 2009]

Ans. The Mucosal Associated Lymphoid Tissues (MALT) are present in the lining of the major tracts,i.e. respiratory, digestive and urogenital tracts. MALT constitutes about 50% of the lymphoid tissue in human body that elicits immune response to antigens along mucosal surfaces.

17.A boy of ten years had chickenpox. He is not expected to have the same disease for the rest of life. Mention how it is possible? [All India 2009]