Topic 3: Infection and Response

Question 1

Pathogens

Answer 1

Microorganisms that enter the body and cause diseases

Question 2

Bacteria

Answer 2

Small cells that reproduce rapidly and produce toxins that damage cells and tissues

Question 3

Viruses

Answer 3

Minute cells that reproduce rapidly using your cell’s machinery and burst out causing cell damage

Question 4

Protists

Answer 4

Single-celled eukaryotes that live inside organisms causing damage

Question 5

Fungi

Answer 5

Single cells or hyphae that grow and penetrate human skin or plant surfaces causing disease

Question 6

Examples of bacterial diseases (2)

Answer 6

1) Salmonella

2) Gonorrhoea

Question 7

Salmonella

Answer 7

SYMPTOMS: fever, stomach cramps, vomiting and diarrhoea
VECTORS: eating contaminated food
TREATMENT: clears up by itself in 3-7 days
PREVENTION: poultry vaccinations

Question 8

What causes salmonella?

Answer 8

Salmonella bacterial toxins

Question 9

Gonorrhoea

Answer 9

SYMPTOMS: pain urinating and thick green discharge
VECTORS: sexual contact
TREATMENT: both oral and injected antibiotics as some strains are resistant
PREVENTION: barrier methods like condoms

Question 10

What causes gonorrhoea?

Answer 10

Neisseria gonorrhoeae bacterial toxins

Question 11

Examples of viral diseases (3)

Answer 11

1) Measles
2) HIV (human immunodeficiency virus)
3) TMV (tobacco mosaic virus)

Question 12

Measles

Answer 12

SYMPTOMS: red skin rash and fever
VECTORS: droplets from infected person’s sneeze or coughs
TREATMENT: clears up by itself in 7-10 days
PREVENTION: MMR vaccine when young

Question 13

What causes measles?

Answer 13

Rubeola virus

Question 14

What are measles’ effects?

Answer 14

Complications can cause pneumonia or encephalitis

Question 15

HIV (Human immunodeficiency virus)

Answer 15

SYMPTOMS: flu-like symptoms and then nothing for several years
VECTORS: sexual contact or exchanging bodily fluids
TREATMENT: antiretroviral drugs but only delays AIDS
PREVENTION: barrier methods such as condoms

Question 16

What causes HIV

Answer 16

Lentivirus

Question 17

What are HIV’s effects

Answer 17

Attacks immune cells until body can’t cope with other infections

Question 18

TMV (tobacco mosaic virus)

Answer 18

SYMPTOMS: mosaic pattern on leaves and discolouration
VECTORS: contact
TREATMENT: none
PREVENTION: destroying affected leaves

Question 19

What are TMV’s effects

Answer 19

Stops plant photosynthesising and growing

Question 20

Example of fungal diseases

Answer 20

Rose black spot

Question 21

Rose black spot

Answer 21

SYMPTOMS: purple or black spots and yellow, dead leaves
VECTORS: water and wind
TREATMENT: fungicides and stripping plant of affected leaves
PREVENTION: destroying affected leaves

Question 22

Example of protist diseases

Answer 22

Malaria

Question 23

Malaria

Answer 23

SYMPTOMS: repeating episodes of fever
VECTORS: mosquitoes infect by inserting protist when sucking blood
TREATMENT: antimalarial medication
PREVENTION: reduce mosquito breeding, insecticides and mosquito nets

Question 24

What causes malaria

Answer 24

Plasmodium protist

Question 25

What are malaria's effects

Answer 25

Potential death

Question 26

Body's defence system (4)

Answer 26

1) Skin - barrier and secretes antimicrobial substances 2) Nose - hair and mucus traps pathogens 3) Trachea and bronchi - mucus traps pathogens 4) Stomach - produce HCl acid

Question 27

Phagocytosis

Answer 27

The most important part of the immune system where white blood cells called phagocytes engulf pathogens and digest them

Question 28

Process of antibody production and phagocytosis (5)

Answer 28

1) B-lymphocytes bind to the pathogen's antigens creating antibodies 2) Some become memory B-cells 3) Mass production of antibodies when exposed to antigen again 4) Antibodies lock onto antigen and agglutinate them 5) Now ineffective, phagocytes engulf and digest pathogen

Question 29

Pros of vaccination (3)

Answer 29

1) Controls previously common communicable diseases 2) Eradicated some diseases like smallpox 3) Prevents epidemics if large populations are vaccinated

Question 30

Cons of vaccination (2)

Answer 30

1) Sometimes don't give immunity | 2) Sometimes causes bad reactions like swelling and fever

Question 31

Process of antibiotic-resistant bacteria

Answer 31

1) Mutations cause some bacteria to become resistant 2) Treating infection will kill non-resistant strains 3) Resistant strains will survive 4) They survive and reproduce

Question 32

Reducing antibiotic-resistant bacteria (2)

Answer 32

1) Avoiding over-prescriptions | 2) Finishing the whole course of drugs

Question 33

MRSA (methecillin-resistant Staphylococcus aureus)

Answer 33

Causes serious wound infections and resistant to powerful antibiotic methecillin

Question 34

Developing drugs (5)

Answer 34

1) Preclinical testing on human tissues and cells 2) Preclinical testing on two different live animals to test efficacy, toxicity and the best dosage 3) Clinical trial on human volunteers starting with low doses, to see side-effects, and then increasing 4) Clinical trial on the ill to find optimum dose (most effective, least side-effects) 5) Results are peer-reviewed to prevent false claims