Question

Explain or discuss the biological and environmental factors that influence the survival of infectious agents or microorganisms

Answer 1

A few harmful microbes less than 1perc of bacteria can invade our body(the host) and could make the person ill.Microbes causes infection and sometimes it may lead to disease.

Infection- The invasion followed by multiplication of pathogen or microbe within individual or population.

Disease- when the infection caused damage to the vital functions or system of individual

To cause an infection pathogen must enter the body through the sites which are known as portal of entry.Mainly their are 4 sites for entry.

Respiratory tract (mouth /nose)- influenza virus

Gastrintestinal tract (Mouth /oral cavity)- vibrio cholera

Urogenital tract - E.coli

Breaks in skin - clostridium tetani

Now for making us ill microbes have to

1) reach the target site of body

2)attach to the target site they are trying to infect so that they are not dislodged

3)multiply rapidly

4)obtain their nutrients from host

5)avoid and survive attack by host immune system.

Environmental factors

There are various factors which are responsible for the survival of microorganisms .

1)pH- The activity of microbial enzyme depends on the fluctuations present on the surface of amino acids.

Any kind of change in environment pH may either enhance the enzyme activity or inhibit activity.Each species of microorganisms show specific pH growth range

2)temperature- Microorganisms are very much sensitive to temp since their temperature varies with that of environment(puikilothermic)

Affecting the rate of chemical reaction and protein structure their integrity affect the enzymatic activity

3) oxygen - some bacteria are capable of growing in presence of oxygen and some in its absence they are called aerobes and anaerobes. Some are obligate and some are facultative aerobes or anaerobes