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1) Interferons are anti-_ protein.
2)Any organism capable of producing a diseases is called_.
3) The organism which spread the diseases from an infected person to a healthy person is called _.
4)The virus that causes acquired immune deficiency syndrome (aids) parasitizes_.
5)_vaccine gives considerable protection against tuberculosis.
6) Diseases are of two main kinds : congenital and _
7) Ability of an organisms to resists diseases is called a _.
Answers
Answer:
The spread of a disease from one person to another is called transmission. There are many
different types of transmission and each one involves a pathogen and a host. The pathogen
can be a bacterium, a virus, a fungus, a parasite, or a prion (a protein particle). These are the
infectious agents that cause illness. Do you remember the vocabulary from the introduction to
this unit? When an organism causes disease in another, the interaction is called parasitism. But
some cause the host no harm at all; this is an interaction called commensalism. Some actually
help the host, and this is called mutualism.
A host is an organism that acts as a home for the pathogen. This can be a human, an animal, or
an insect. The environment is also an important part of transmission because in order for the
disease to spread, the habitat of the pathogen and host must overlap somehow. The environment
includes both natural and social aspects. The types of diseases that are common (or endemic)
in particular areas relate to environmental factors such as temperature, rainfall, and proximity
to bodies of water. Social factors affect how humans interact with one another. For example, a
pathogen may spread more easily from one person to another in a crowded home or classroom.
Figure 1 can help you remember the three important parts of transmission.
Figure 1. Agent-Host-Environment Triad
Modes of Transmission
1. Airborne / Respiratory
Examples: Influenza, Severe Acute Respiratory Syndrome (SARS), Tuberculosis
A pathogen may be spread from one person to another by airborne particles from a cough or
sneeze. Respiratory droplets containing an infectious agent, such as the influenza virus, are
propelled through the air. These droplets may land in the nose or mouth of someone nearby or
on an object such as a doorknob that someone may touch. For influenza, infectivity is relatively
high, which means that the disease spreads easily from person to person. Symptoms of influenza
include fever, cough, fatigue, runny or stuffy nose, muscle aches, and nau