What You Need to Know

Key Concept Diagram

Infectious diseases are caused by pathogens and can spread between individuals

The immune system has two lines of defence: physical barriers (skin, mucus) and the immune response (white blood cells, antibodies)

Antibodies are proteins produced by white blood cells that target specific pathogens

Vaccines expose the immune system to a weakened or dead pathogen, training it to respond quickly if the real pathogen is encountered

Key Vocabulary

Pathogen

A microorganism that causes disease, e.g. bacteria, viruses, fungi, or parasites

Immune system

The body's system of defences against infection and disease

Antibody

A protein produced by white blood cells that attaches to a specific pathogen, marking it for destruction

Vaccine

A preparation that stimulates the immune system to develop immunity to a specific disease without causing the disease itself

Knowledge Check

Select the correct answer for each question. Click "Check Answer" to see if you are right.

Question 1

Which of the following is a pathogen?

Influenza virus A strand of DNA A red blood cell Haemoglobin

Question 2

What is the role of antibodies in the immune response?

To carry oxygen around the body To attach to specific pathogens and mark them for destruction To break down food in the digestive system To regulate body temperature

Question 3

How do vaccines protect people from disease?

They kill all bacteria in the body They replace white blood cells with artificial ones They expose the immune system to a harmless form of the pathogen, allowing it to develop immunity without getting sick They increase the body's temperature to kill pathogens

Disease and Immunity