B3: Infection & Response

Question 1

What is a pathogen?

Answer 1

A micro-organism that causes disease

Question 2

What are the 4 types of pathogens?

Answer 2

• Bacteria
• Viruses
• Fungi
• Protists

Question 3

How do viruses reproduce?

Answer 3

Inserting genes into cells which causes them to produce more copies

Question 4

What are measles and how is it spread?

Answer 4

A virus that causes a rash
Spread by droplets

Question 5

What is HIV?

Answer 5

An STD/STI that causes AIDS - compromised immune system

Question 6

How does bacteria make you feel ill?

Answer 6

Releases toxins into your body that damage cells

Question 7

How is salmonella transmitted and what are it’s effects?

Answer 7

Through undercooked food with bacteria
Food poisoning;
- fever
- abdominal cramps
- vomiting
- diarrhoea

Question 8

What is gonorrhoea?

Answer 8

An STD
Causes yellow discharge

Question 9

What do fungi do?

Answer 9

Damage cells

Question 10

What are protists?

Answer 10

Single-celled organisms

Question 11

How are protists transmitted?

Answer 11

Through vectors e.g. mosquitoes

Question 12

What causes malaria?

Answer 12

A protist that infects red blood cells

Question 13

What is rose black spot?

Answer 13

A fungus that causes leaves to fall off
Can be treated with fungicides

Question 14

What is tobacco mosaic virus (TMV)?

Answer 14

A virus that results in the discolouration of leaves due to less chlorophyll and therefore stunted growth

Question 15

What are human defences against pathogens?

Answer 15

• Skin - physical barrier
• Mucus in nose/trachea - traps
• Acid & enzymes - kill

Question 16

What are plant defences against pathogens?

Answer 16

• Cell wall, waxy cuticle, bark - barriers
• Antibacterial chemicals
• Poison/thorns to deter other organisms

Question 16

How do lymphocytes remember pathogens and help make you immune?

Answer 16

Once the correct antibody is found, T cells store it in your lymph nodes, ready for next time

Question 16

What are lymphocytes?

Answer 16

A type of white blood cell that produces antitoxins to neutralise toxins made by pathogens and antibodies that bind to the antigen of a pathogen
This stops viruses from infecting cells and causes them to clump together

Question 16

Where does aspirin come from?

Answer 16

Willow trees

Question 17

What are phagocytes?

Answer 17

A type of white blood cell that will ingest pathogens

Question 17

What is a vaccine?

Answer 17

A dead/inert version of a virus that is injected into your body so that you can gain immunity without becoming ill

Question 17

What is are disadvantages of antibiotics?

Answer 17

• Difficult to make them target specific bacteria, and not damage our cells or other ‘good’ bacteria
• Whole course must be taken to kill all bacteria, or more resistant bacteria will survive and multiply

Question 18

Where does penicillin come from?

Answer 18

A mould

Question 19

What are synthetic drugs trialled for?

Answer 19

• Efficacy
• Toxicity
• Dose

Question 20

What are the steps in producing a drug?

Answer 20

• Computer testing
• Tested on cell tissue, then animals, then humans

Question 21

What is a blind trial?

Answer 21

A test group are given a drug, a control group are given a placebo, without being made aware

Question 22

What is a double blind trial?

Answer 22

Doctors do not know which is which, to eliminate bias

Question 23

What are monoclonal antibodies?

Answer 23

Produced by clones of a cell that produces a desired antibody?

Question 24

What are the steps in producing monoclonal antibodies?

Answer 24

• Lymphocytes from mice are combined with tumour cells to make a hybridoma
• Hybridoma multiply, producing lots of the same antibody

Question 25

What are uses of monoclonal antibodies?

Answer 25

• Combat diseases
• Medical diagnosis
• Pathogen detection
• Identifying molecules; dye is bound to antibodies, which attach to specific molecules

Question 26

What are disadvantages of monoclonal antibodies?

Answer 26

Side effects are worse than scientists expected

Question 27

How can pathogens be spread?

Answer 27

• Air
• Water
• Direct contact