4.1 Communicable diseases

Question 1

Name the 4 types of pathogens-

Answer 1

Bacteria, viruses, fungi and protoctista

Question 2

What is a communicable disease?

Answer 2

A disease that is caused by a pathogen and transmitted directly between organisms

Question 3

Bacteria definition-

Answer 3

Prokaryotic cells that have cell walls but lack organelles. Some bacteria are
pathogenic, producing toxins that damage host cells

Question 4

2 ways bacteria can be classified-

Answer 4

By their basic shapes, by their cell walls

Question 5

Virus definition-

Answer 5

Non-living infectious agents that invade host cells and take over cell metabolism,
replicating within them

Question 6

Protoctista definition-

Answer 6

A group of eukaryotic, single-celled microorganisms that may cause disease.
They digest cells and use the cell contents to reproduce

Question 7

Fungi definition-

Answer 7

Eukaryotic, often multicellular organisms that may cause disease. They digest and
destroy cells, and produce spores that can spread rapidly between organisms

Question 8

Name the 4 plant diseases-

Answer 8

Ring rot, Tobacco mosaic virus, Potato/ tomato late blight, Black sigatoka

Question 9

What does ring rot infect?

Answer 9

Potatoes, tomatoes, aubergines

Question 10

What pathogen causes ring rot?

Answer 10

Bacteria (gram positive)

Question 11

How does ring rot bacteria damage plants?

Answer 11

Bacteria infects the vascular tissue and prevents the transport of water. It spreads into tubers where vascular tissue is arranged in a ring. It also damages fruit and leaves

Question 12

Is there a cure for ring rot?

Answer 12

There is no cure and once bacterial ring rot infects a field, it cannot be used to grow crops again for at least two years.

Question 13

What does tobacco mosaic virus infect?

Answer 13

Tobacco plants and around 150 other species e.g. tomatoes, peppers, cucumbers, petunias

Question 14

What pathogen causes tobacco mosaic virus?

Answer 14

Virus

Question 15

How does tobacco mosaic virus damage plants?

Answer 15

It damages the leaves, flower and fruit. It causes a distinct yellowing of leaves which produces a mosaic pattern, and stunts growth

Question 16

Is there a cure for tobacco mosaic virus?

Answer 16

There is no cure but resistant crop strains are available

Question 17

What does potato blight damage?

Answer 17

Tomatoes and potatoes

Question 18

What pathogen causes potato blight?

Answer 18

Fungus-like protoctist

Question 19

How does potato blight damage plants?

Answer 19

Hyphae penetrate host cells and damage leaves, tubers and fruit

Question 20

Is there a cure for potato blight?

Answer 20

No cure but resistant crop strains are available

Question 21

What does black sigatoka infect?

Answer 21

Banana plants

Question 22

What pathogen causes black sigatoka?

Answer 22

Fungus

Question 23

How does black sigatoka damage plants?

Answer 23

Hyphae penetrate and digest cells turning the leaves black

Question 24

Is there a cure for black sigatoka?

Answer 24

No cure but resistant crop strains are being developed

Question 25

How is ring rot transmitted?

Answer 25

Direct contact of seed potato tubers, sharing equiptment, soil contamination

Question 26

How is ring rot treated/ prevented?

Answer 26

Spacing harvest, good field hygiene, not using field for 2 years after infection

Question 27

How is tobacco mosaic virsus transmitted?

Answer 27

Direct contact between leaves, contaminated tools/ workers hands

Question 28

How is tobacco mosaic virus treated/ prevented?

Answer 28

Remove diseased plants, good field hygiene, crop rotation

Question 29

How is potato blight transmitted?

Answer 29

Spores carried by wind/ water

Question 30

How is potato blight treated/ prevented?

Answer 30

Chemical treatment, careful management, spacing harvest

Question 31

How is black sigatoka transmitted?

Answer 31

Spores carried by wind/ water

Question 32

How is black sigatoka treated/ prevented?

Answer 32

Use of fungicide, remove infected leaves

Question 33

What does tuberculosis infect?

Answer 33

Humans, badgers, cows, pigs, deer

Question 34

What pathogen causes tuberculosis?

Answer 34

Bacteria

Question 35

What damage does tuberculosis cause?

Answer 35

Damages lung tissue and suppresses immune system so more susceptible to other diseases. Causes chronic cough and bloody mucus

Question 36

Is there a cure for tuberculosis?

Answer 36

Curable using antibiotics

Question 37

What does bacterial meningitis infect?

Answer 37

Humans, usually very young children and teenagers

Question 38

What pathogen causes bacterial meningitis?

Answer 38

Bacteria

Question 39

What damage does bacterial meningitis cause?

Answer 39

Damages meninges of the brain which can spread to the body to cause septicaemia

Question 40

Is there a cure for bacterial meningitis?

Answer 40

Curable using antibiotics

Question 41

What does influenza infect?

Answer 41

Humans, birds, pigs

Question 42

What pathogen causes influenza?

Answer 42

Virus

Question 43

What damage does influenza cause?

Answer 43

Kills ciliated epithilial cells in respiratory system, leaving airways open to secondary infection

Question 44

Is there a cure for influenza?

Answer 44

No cure although vulnerable groups are given flu vaccine in attempt to protect against new strains

Question 45

What does ring worm infect?

Answer 45

Mammals including humans, cattle, cats, dogs

Question 46

What pathogen causes ring worm?

Answer 46

Fungus

Question 47

What damage does ring worm cause?

Answer 47

Not overly damaging but may be itchy. Causes grey- white, crusty, infectious areas of skin

Question 48

Is there a cure for ring worm?

Answer 48

Antifungal creams

Question 49

What does athletes foot infect?

Answer 49

Humans

Question 50

What pathogen causes athletes foot?

Answer 50

Fungus

Question 51

What damage does athletes foot cause?

Answer 51

Grows on and digests warm, moist skin between the toes

Question 52

Is there a cure for athletes foot?

Answer 52

Antifungal creams

Question 53

What does HIV infect?

Answer 53

Humans

Question 54

What pathogen causes HIV?

Answer 54

Virus

Question 55

What damage does HIV cause?

Answer 55

Targets T helper cells in immune system and gradually destroys immune system so affected people are open to other infections

Question 56

Is there a cure for HIV?

Answer 56

No cure but antiretrovial drugs slow the progress of the disease

Question 57

What does malaria infect?

Answer 57

Humans

Question 58

What pathogen causes malaria?

Answer 58

Protoctist

Question 59

What damage does malaria cause?

Answer 59

Destroys red blood cells in the liver and brain. Causes fever, fatigue, chills

Question 60

Is there a cure for malaria?

Answer 60

No vaccine and limited cures

Question 61

How is tuberculosis transmitted?

Answer 61

Droplets (coughs and sneezes)

Question 62

How is tuberculosis treated/ prevented?

Answer 62

Improving living standards, vaccines

Question 63

How is bacterial meningitis transmitted?

Answer 63

Droplets (coughs and sneezes), very close contact e.g. kissing

Question 64

How is bacterial meningitis treated/ prevented?

Answer 64

Vaccines

Question 65

How is influenza transmitted?

Answer 65

Droplets (coughs and sneezes), hands touching infected surface and then touching face

Question 66

How is influenza treated/ prevented?

Answer 66

Vaccines, wash hands

Question 67

How is ring worm transmitted?

Answer 67

Direct contact with infected person or contaminated surfaces

Question 68

How is ring worm treated/ prevented?

Answer 68

Avoid contact with infected people

Question 69

How is athletes foot transmitted?

Answer 69

Direct contact with infected person or contaminated surfaces

Question 70

How is athletes foot treated/ prevented?

Answer 70

Keep feet clean and dry, wear shoes in areas where infected feet have been

Question 71

How is HIV transmitted?

Answer 71

Exchange of bodily fluids

Question 72

How is HIV treated/ prevented?

Answer 72

Condoms, don't share needles

Question 73

How is malaria transmitted?

Answer 73

Bites of infected mosquitos, sexually in mosquitos

Question 74

How is malaria treated/ prevented?

Answer 74

Control vector e.g. insecticides, remove standing water where they breed, mosquito nets, window+door screen, long sleeved clothing