B1 - Staying healthy

Question 1

Why are babies feeding bottles sterilised?

Answer 1

To get rid of any microorganisms which cause disease.

Question 2

What are pathogens?

Answer 2

A pathogen is something that can cause a disease.

Question 3

What are the four types of pathogen?

Answer 3

• fungi
• bacteria
• viruses
• protozoa

Question 4

What does contagious mean?

Answer 4

Contagious is when a disease spreads directly from person to person.

Question 5

How are pathogens prevented from entering the body?

Answer 5

• skin stops entry
• hydrochloric acid in stomach kills pathogens
• sticky mucus lines mucus membranes in breathing system trapping them
• blood clots seal wound preventing entry

Question 6

What are vectors?

Answer 6

Vectors carry microorganisms that cause diseases but do not suffer from the disease themselves.

Question 7

What is a parasite?

Answer 7

An organism which lives in or on another organism (its host) and benefits by deriving nutrients at the other’s expense

Question 8

What is the difference between benign tumours and malignant tumours?

Answer 8

Malignant tumours move around the body and are cancerous whereas benign tumours are usually harmless.

Question 9

What do white blood cells do?

Answer 9

• surround and engulf pathogens such as bacteria

- make antibodies that stick the pathogens together

Question 10

What is active immunity?

Answer 10

The immunity which results from the production of antibodies by the immune system in response to the presence of an antigen.

Question 11

What is passive immunity?

Answer 11

The short-term immunity which results from the introduction of antibodies from another person or animal.

Question 12

Which type of pathogens can be controlled by antibiotics?

Answer 12

Bacteria.

Question 13

What type of pathogen is controlled by antivirals?

Answer 13

Viruses.

Question 14

What is the difference between antibiotics and antivirals?

Answer 14

Antibiotics destroy the pathogen whereas antiviral drugs slow down the pathogen’s development.

Question 15

What does the body react to when it is infected?

Answer 15

• antigens on the surface of a foreign invader
• toxins that are produced by pathogens
• damage to his cells caused by the pathogen

Question 16

What is an antigen?

Answer 16

A toxin or other foreign substance which induces an immune response in the body

Question 17

What are the two types of white blood cell?

Answer 17

• phagocytes

- lymphocytes

Question 18

What do phagocytes do?

Answer 18

• ingest and absorb the pathogens or toxins

- release an enzyme to destroy them

Question 19

What do lymphocytes do?

Answer 19

When a lymphocyte with the appropriate antibody meets the antigen, the lymphocyte reproduces quickly to make many copies of the antibody that neutralises the pathogen.

Question 20

What is a placebo?

Answer 20

A dummy pill.

Question 21

What is a blind trial?

Answer 21

A blind trial is where a patient does not know whether they are receiving medication or a placebo.

Question 22

What is a double blind trial?

Answer 22

A double blind trial is where neither the patient or the doctor know who is receiving a placebo and who is receiving medication.

Question 23

Why are placebos rarely used in human trials?

Answer 23

Many doctors do not like giving patients with a disease a placebo. They feel the patient will not benefit from taking a fake drug, and will not get better. They do not think this is fair to the patient.