spread of disease

Question 1

pathogen

Answer 1

A pathogen is a disease-causing organism, Pathogens are passed on from one host to another and therefore the diseases they cause are known as transmissible diseases

Question 2

Pathogens can be passed on from host to host in different ways

Answer 2

Direct contact – the pathogen is passed directly from one host to another by transfer of body fluids such as blood or semen (eg HIV, gonorrhoea, hepatitis B & C)
Indirect contact – the pathogen leaves the host and is carried in some way to another, uninfected individual

Question 3

There are 3 main ways in which the body defends itself against disease:

Answer 3

Mechanical barriers
Chemical barriers
Cells

Question 4

Mechanical barriers

Answer 4

skin and hair up the nose

Question 5

chemical barriers

Answer 5

mucus ,stomach acid

Question 6

cells

Answer 6

By phagocytosis – engulfing and digesting pathogenic cells, By producing antibodies