BIOLOGY-Pathogen and Immunity

Question 1

List three diseases caused by Pathogens?

Answer 1

for example: Rabies, Malaria, Influenza, Polio, Cholera,

AIDS, Food poisoning

Question 2

Outline four ways which the body prevents pathogens

from entering?

Answer 2

For example: Layer of dead cells covering the skin; Blood clotting; Cilia and Mucus in the respiratory passages; Hydrochloric Acid in the stomach

Question 3

Why is raw sewage a Health Risk?

Answer 3

It may contain pathogen, such as the bacteria that cause cholera or the viruses that cause polio

Question 4

Describe and explain what happens to the number of bacteria the second time a person comes into contact
with the bacteria?

Answer 4

The number of bacteria stays low. This is because memory cells are already present in the person, so the appropriate antibody is made almost immediately, preventing the bacteria from reproducing.

Question 5

Explain why the number of antibodies does not begin to rise immediately after the first infection?

Answer 5

It takes time for the lymphocytes to recognise the bacterium, and for that can make a appropriate antibody to produce a clone of themselves. Only then is the antibody produced in large quantities.

Question 6

Describe three ways in which Pathogens can be transmitted from one person to another?

Answer 6

By direct contact; in droplets in the air (into the respiratory passages); in food or water; via a vector

Question 7

Explain why household waste should be covered?

Answer 7

To prevent animal such as houseflies or rats getting to it; these animals can pick up pathogens from the food and transmit them to other, fresh, food that might be eaten.