7A - Causes of infectious disease

Question 1

What is a pathogen?

Answer 1

A biological agent that causes disease or illness in a host organism

Question 2

Pathogens live and reproduce at the expense of the host organisms and cause disease by:

Answer 2

releasing toxins
damaging tissue
competing for nutrients

Question 3

What are the two types of pathogens?

Answer 3

Cellular organisms
e.g. Bacteria, fungi, protozoans, Ectoparasites (Live outside organism) and Endoparasites (Live inside organism)

Non-cellular organisms
e.g Bacteria, prions

Question 4

What is a disease?

Answer 4

Any condition that impairs the normal functioning of an organism

Question 5

What is the endemic level?

Answer 5

The typical base-line level of disease in a population, which doesn’t increase or decrease in frequency

Question 6

What is an epidemic?

What is a pandemic?

Answer 6

Epidemic =
A sudden in crease of a particular disease among the population of a given area

Pandemic =
When a disease reaches above endemic levels on a global scale and epidemics are occurring across multiple countries or continents

Question 7

How do pathogen transmit disease?

Question 8

What is increased pathogen virulence?