Question

FINAL EXAM DR. HASSAN 7) The normal habitat of Staphylococcus a) b) aureus may be: Urinary tract Stomach Healthy tissues Nose, throat, and skin Scalp Clostridium perfringens may be found as a part of the normal flora in: a) Mouth b) Intestines Lungs Urinary tract Wounds 9) A disease constantly present in a locality is said to be: a) b) Endemic Epidemic Pandemic Sporadic Reservoir Foreign substances that induce a specific immune response after gaining entrance to the body are termed: a) 10) Antigens Antibodies b) c) Cytolysins d) Complement None of the above e) Essential properties of an antigen are: a) It must be foreign to the host It must be degradable by the host b) It must be a large molecule and possess at least two different determinant groups c) It must possess a three-dimensional or tertiary d) All of the above e) 11) structure

Answer 1

7. D

Staphylococcus aureus is a gram positive spherical bacterium. It is a commensal inhabitant of upper respiratory tract and skin in humans. It is a member of firmicutes. In humans body it maintains an optimum ph in the organs where it is found to prevent the growth of pathogens

8. B

Clostridium perfrigenes is a gram positive spore forming bacterium. It is normally present in intestine of human beings. It is also found in raw meat amd poultry.

9. A

Endemic disease is the one which is mainly present in a certain population or region. Eg, malaria is found mainly in population of South Africa.

Pandemic is a worldwide spread of diease.

Epidemic is an outbreak of a disease which affects many people at a time.

Sporadic is a disease which occurs in patches. It occurs occasionally.

A reservoir is an affected person thay can spread infectious diseases.

10. A

Definition of antigen

11. E

An antigen is a foreign substance which is recognised by the immune system of our body as non self and is subject to degradation. Thus, A and B are correct.

An antibidy is a protein molecule which binds an antigen by using its antigen determinant. Each anitbody molecule has 2 sites for binding antigens.

An antigen is a protein in nature and we know that proteins are active when present in their tertiary or quaternary structure. So, D is also correct.

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