question_answer

(i) Typhoid and pneumonia are the bacterial diseases that infect human beings. Discuss the causative agent, symptoms and the way in which they infect the human body?

(ii) Give one viral disease also. Mention its causative agent and vectors.

Or

What is an antibody? Give structure and its different types.

Answer:

(i) Typhoid and pneumonia are bacteria) diseases that infect human in one or the other way out.

Typhoid It is a disease caused by bacterium, Salmonella typhi.

Way of entry It enters the small intestine through contaminated water and food and migrates to other organs of the body through blood.

Symptoms Its symptoms include

High fever \[(39-40{}^\circ C)\]

Weakness

Stomach pain

Constipation

Headache and

Loss of the appetite.

Death may also occur in serious cases.

Pneumonia It is caused by the bacterium Streptococcus pneumoniae and Haemophilus influenzae. It infects alveoli of lungs.

Way of entry It enters the body by inhaling the droplets released by an infected person and also by sharing glasses and utensils with an infected person.

Symptoms It includes fever, chills, cough and headache.

In severe cases, lips and finger nail may turn greyish to bluish in colour.

(ii) Chikungunya is a viral disease.

Causative agent Its causative agent is Chikungunya virus.

Vector It is transmitted by the bite of Aeotes aegyptii.

Or

An antibody is a type of protein molecule produced by the B - lymphocytes in response to exposure to an antigen. It has four peptide chains. Of these chains, two are smaller called as Light chains (L) and two are longer called as Heavy chains (H). So, it is designated as\[{{H}_{2}}{{L}_{2}}\]. Antibody mediated response is called as humoral immune response.

The different types of antibodies produced in the body are IgG, IgM, IgA, IgE and IgD.

The structure of an antibody molecule is as follows