Human Infection and Response Year 9

Question 1

What is a pathogen

Answer 1

Microorganism that causes disease

Question 2

What is a microorganism?

Answer 2

Organisms that can only be seen by a microscope?

Question 3

Name four types of pathogens

Answer 3

Bacteria, virus, protist, fungi

Question 4

What is bacteria?

Answer 4

A single-celled microorganism

Question 5

What is a virus?

Answer 5

Non-cellular organism that replicates in cell of living host

Question 6

What is a protist?

Answer 6

Eukaryotic single-celled organism

Question 7

What is fungi?

Answer 7

Large group of microorganisms with single-celled yeasts, mould and mushrooms

Question 8

Name types of transmission that pathogens spread in

Answer 8

Infected water, contaminated food, air droplets, direct contact, body fluids, animal vectors

Question 9

How does bacteria reproduce?

Answer 9

Binary fission, every 20 minutes

Question 10

How does a virus infect a human?

Answer 10

Attaches to cell, injects DNA into cell, DNA takes over cell and starts replicating, viruses begin to infect new cell

Question 11

What is a toxin?

Answer 11

Poison released by bacteria when it enters the cell, making victim feel ill

Question 12

What are measles?

Answer 12

Very infectious viral disease that shows skin rash and fever as symptoms?

Question 13

How does measles spread?

Answer 13

Air droplets from sneezes, coughs or breathing

Question 14

What is HIV(Human Immunodeficiency Virus)?

Answer 14

Virus that attacks immunity system

Question 15

When do symptoms of HIV start to surface?

Answer 15

2-4 weeks after exposure

Question 16

What are antiretrovial drugs?

Answer 16

Drugs used to stop virus replicating in body

Question 17

How is HIV transmitted?

Answer 17

Sexual contact or bodily fluids

Question 18

Life cycle of HIV

Answer 18

Unless successfully controlled by drugs, virus enters lymph nodes and attacks immune system. Months/years later, untreated HIV becomes AIDS and body can’t defend itself against other diseases.

Question 19

What is salmonella?

Answer 19

A bacteria that spreads food poisoning

Question 20

What are the symptoms of salmonella?

Answer 20

Fever, abdominal cramps, vomiting, diarrhoea

Question 21

How is salmonella transmitted?

Answer 21

Ingestion of contaminated food

Question 22

What is gonorrhoea?

Answer 22

Sexually transmitted disease caused by bacteria

Question 23

What are the symptoms of gonorrhoea?

Answer 23

Thick yellow/green discharge from penis or vagina and pain while urinating

Question 24

What is penicillin?

Answer 24

Antibiotic that treats gonorrhoea

Question 25

How is gonorrhoea spread?

Answer 25

Sexual conduct

Question 26

How is gonorrhoea prevented?

Answer 26

Using a condom during sex

Question 27

What is an antibiotic?

Answer 27

A medicine used to cure bacterial disease by killing infective bacteria

Question 28

What is malaria?

Answer 28

A disease caused by protist pathogens

Question 29

Life cycle of malaria

Answer 29

Mosquitos carrying Plasmodium protist infect people by biting them. The saliva of mosquito passes through victim's skin and into their bloodstream. Saliva carries a parasite that circulates in blood, then settles in liver where it multiplies. Days later, the liver cells, now containing thousands of parasites, ruptures and parasites move to red blood cells, where they then release toxins.

Question 30

What are symptoms of malaria?

Answer 30

Recurrent episodes of fever

Question 31

Name defence systems of body against pathogens

Answer 31

Skin, nose, trachea and bronchi, stomach

Question 32

How does skin defend body?

Answer 32

Produces antimicrobial secretions that help prevent pathogen's growth

Question 33

How does nose defend body?

Answer 33

Traps particles that may contain pathogens

Question 34

How does trachea and bronchi defend body?

Answer 34

It secretes mucus that traps pathogens, and cilia wafts mucus to back of the throat, where it is swallowed

Question 35

How does stomach defend body?

Answer 35

It produces hydrochloric acid that kills majority of pathogens that enter via the mouth

Question 36

What is phagocytosis?

Answer 36

Process that engulfs and destroys pathogens

Question 37

What are phagocytes?

Answer 37

White blood cells that engulf and absorb wasteful or harmful material?

Question 38

How do phagocytes function?

Answer 38

They use their large-lobed nucleus to stretch around bacteria, engulf it and digest it using enzymes

Question 39

What is an antibody?

Answer 39

Protein produced by immune system that attacks antigens

Question 40

What is an antigen?

Answer 40

Protein on pathogen's surface that triggers an immune response

Question 41

What are lymphocytes?

Answer 41

White blood cells that produce antibodies

Question 42

How to antibodies help destroy pathogen?

Answer 42

By binding/attaching to pathogen

Question 43

What do some lymphocytes become?

Answer 43

Memory cells, that produce antibodies again quickly if same pathogen enters body again

Question 44

What is an antitoxin?

Answer 44

Substance produced by white blood cells that can neutralise toxins?

Question 45

How to antitoxins neutralise toxins?

Answer 45

Binding to toxins

Question 46

What is vaccination?

Answer 46

Process of injecting small quantities of dead or inactive pathogens to stimulate white blood cells to produce antibodies

Question 47

What does vaccinating a large part of the population do?

Answer 47

Reduce spread of pathogen

Question 48

What should specific bacteria be treated with?

Answer 48

Specific antibiotics

Question 49

Can antibiotics kill viral pathogens?

Answer 49

No

Question 50

What is a painkiller?

Answer 50

Medicine that treats disease's symptoms but doesn't kill the pathogen

Question 51

Why is it difficult to develop virus-killing drugs?

Answer 51

Because it difficult to do this without damaging body's tissues