3. Infection and Response (non specific and specific defence systems, vaccinations)

Question 1

What are the 4 ways the spread of a disease can be reduced or prevented?

Answer 1

• being hygienic
• destroying vectors
• isolating infected individuals
• vaccination

Question 2

What is an example of using hygiene to prevent the spread of disease?

Answer 2

Washing hands thoroughly before preparing food or after sneezing can prevent infecting another person

Question 3

How does destroying vectors prevent the spread of disease?

Answer 3

By getting rid of the organisms that spread disease, you can prevent the disease from being passed on

Question 4

How can vectors be killed?

Answer 4

Using insecticides or by destroying their habitat so that they can no longer breed

Question 5

How does isolating infected individuals help prevent the spread of disease?

Answer 5

Isolating someone who has a communicable disease, prevents them from infecting anyone else

Question 6

How does vaccination help prevent disease?

Answer 6

Vaccinating people or animals means that they cannot develop the infection and then pass it on to someone else

Question 7

What are examples of the non-specific defense systems of the body?

Answer 7

• skin
• mucus
• cillia
• stomach
• eyes
• ears

Question 8

How is the skin a non-specific defense system?

Answer 8

It provides a physical barrier against pathogens

Question 9

What is the mucus and how is it a non-specific defense system?

Answer 9

It is a sticky substance produced by goblet cells, which trap pathogens

Question 10

How is the cillia a non-specific defense system?

Answer 10

They beat together, creating a sweeping motion that sweeps mucus to the back of the throat to either be coughed/sneezed out or swallowed

Question 11

What do the cillia line?

Answer 11

The trachea and Bronchi

Question 12

How is the stomach a non-specific defense system?

Answer 12

It has hydrochloric acid with a low pH of 1-2 which kills the pathogens

Question 13

How are eyes a non-specific defense system?

Answer 13

The eyes produce tears with enzymes, lysosomes, that can break down pathogens

Question 14

How are the ears a non-specific defense system?

Answer 14

Ear wax traps pathogens

Question 15

What is the adaptive immune response from white blood cells?

Answer 15

1. Phagocytes, perform phagocytosis, where they engulf the pathogens and digest it
2. Lymphocytes produce antibodies that are specific and complementary to the antigens on pathogens. They will bind to the antigen and stop them from causing any further damage
3. They also produce anti-toxins which counteract and neutralise the toxins produced by bacteria

Question 16

What are lymphocytes?

Answer 16

A type of white blood cell

Question 17

What do bacteria produce?

Answer 17

Toxins

Question 18

What do viruses do in the body?

Answer 18

• They will invade the hosts body cells and use the cell machinery to replicate
• They will continue to do this until the cell bursts and re-infects other cells

Question 19

What can antibiotics be used for?

Answer 19

Bacterial infections only, not viral infections

Question 20

How do vaccinations work?

Answer 20

• A weakened or inactive form of the pathogen gets injected into the body
• White blood cells detect the antigens on the pathogens
• This causes it to produce antibodies that are specific and complementary to the antigens
• This is a primary immune response. These will be stored by memory white blood cells
• So during the secondary immune response, you produce more antibodies, more quickly, so you wouldn’t show the symptoms of being infected

Question 21

What are the pros of vaccination?

Answer 21

1).Help control communicable diseases e.g smallpox
2).Prevent epidemics

Question 22

What are the cons of vaccination?

Answer 22

1). Vaccines don’t always work - sometimes they don’t give you immunity
2). You can sometimes have a bad reaction to a vaccine (eg. swelling, fevers)