Infection and response

Question 1

Pathogens

Answer 1

Microorganisms that cause infectious diseases, which harm the body. Common pathogens are bacteria and viruses.

Question 2

Infectious diseases

Answer 2

Caused by microorganism entering and attacking a body. People can pass these microorganisms from one person to another, meaning it is infectious.

Question 3

Viruses

Answer 3

Smaller than bacteria. They have regular shapes. Viruses live and reproduce rapidly inside the cell, causing damage.

Question 4

Bacteria

Answer 4

Divide rapidly in the body by splitting in two(binary fission). They often produce toxins which make us ill. Sometimes they directly damage the cells.

Question 5

Disease symptoms

Answer 5

• high temperature
• headaches
• rashes

Question 6

Droplet infection

Answer 6

When you are ill, you expel tiny droplets full of pathogens from the breathing system. Other people breath in the tiny droplets with pathogens.

Question 7

Direct contact

Answer 7

Spread by direct contact with the skin.

Question 8

Contaminated food and drink

Answer 8

By taking large numbers of microorganisms straight into the gut. (raw, undercooked or contaminated food)

Question 9

Through a break in your skin

Answer 9

Pathogens such as HIV/Aids can enter your body through cuts and scratches.

Question 10

How body prevents microorganisms getting in

Answer 10

• skin covers the body and acts as a barrier, preventing bacteria to reach tissues
• a scab forms a seal over the cut, stopping pathogens
• mucus in the respiratory system traps the pathogens
• stomach acid destroys most of the pathogens

Question 11

Phagocytosis

Answer 11

A process of phagocyte white blood cells ingesting pathogens to digest them and destroy them.

Question 12

Antibodies

Answer 12

Special chemical. These targets particular bacteria or viruses and destroy them.

Question 13

Antitoxines

Answer 13

This counteracts the toxins released by the pathogens.

Question 14

Antigens

Answer 14

Every cell has unique protein on the surface. The antigens of microorganisms getting to the body are different, so the immune system can recognise it.

Question 15

The first time you meet a new pathogen…

Answer 15

you will get ill because there is a delay whilst your body sorts out the antibody that is needed.

Question 16

The memory white blood cells will…

Answer 16

remember the right antibody needed to destroy a particular pathogen. If you meet the same pathogen again, they are to produce the antibody very quickly.

Question 17

Vaccination

Answer 17

Also known as immunisation. The small quantity of vaccine is introduced into the body. This stimulates the white blood cells to produce antibodies that destroy the pathogen.

Question 18

Vaccine

Answer 18

Is made up of dead or inactivated form of the pathogen.

Question 19

Vaccination makes the person immune to…

Answer 19

future infections by the pathogens, because the body can respond rapidly making the correct antibodies, in the same way as if the person had the diseases previously.

Question 20

The MMR vaccine

Answer 20

Used to prevent children against measles, mumps and rubella.

Question 21

Immunity

Answer 21

Is the ability of white cells called memory cells to produce the right antibodies quickly if you are re-infected by a pathogen.

Question 22

Herd immunity

Answer 22

If a large proportion of the population is immune to a pathogen the spread of disease is greatly reduced.