12.2 Animal and Plant Diseases

Question 1

What are the 4 common plant diseases?

Answer 1

Ring rot
Potato blight
Tobacco Mosaic Virus
Black Sigatoka

Question 2

What is ring rot?

Answer 2

A bacterial disease of potatoes, tomatoes and aubergines, caused by Gram-positive bacteria.

Question 3

What damage does ring rot cause?

Answer 3

Ring rot damages leaves, tubers and fruit.

Ring rot can destroy 80% of a field and there’s no cure.

Question 4

Once ring rot infects a field, how long do you have to wait to grow potatoes again in the same field.

Answer 4

2 years

Question 5

What is Tobacco Mosaic Virus (TMV)?

Answer 5

A virus that infects tobacco plants and 150 species of plants, including tomatoes and cucumbers.

Question 6

What damage does TMV cause?

Answer 6

TMV damages leaves, flowers and fruit

TMV stunts plant growth and reduces yield, leading to almost complete crop loss

Question 7

How can the spread of TMV be prevented?

Answer 7

Resistant strains are available, but once infected, there’s no cure

Question 8

What is potato blight (+ other blights) caused by?

Answer 8

Fungus-like protoctist oomyecete.

Question 9

What damage does potato blight cause?

Answer 9

The hyphae penetrate host cells, destroying leaves, tubers and fruit, causing millions of £ of crop damage annually

Question 10

How can you reduce the risk of potato blight?

Answer 10

Resistant strains are available, but there’s no cure.

Careful management and chemical treatment can reduce the risk of infection

Question 11

What is black sigatoka?

Answer 11

A banana disease caused by fungus

Question 12

What damage does black sigatoka cause?

Answer 12

Attacks and destroys leaves.
The hyphae penetrate and digest cells, turning leaves black.
If infection occurs, up to 50% loss can occur

Question 13

How can the spread of black sigatoka be prevented?

Answer 13

Resistant strains are being developed.

Good husbandry and fungicide treatment can control the spread, but there’s no cure.

Question 14

What is a fungicide?

Answer 14

A chemical that kills fungi

Question 15

What are the 4 common animal diseases?

Answer 15

Tuberculosis (TB)
Bacterial Meningitis
HIV/AIDS
Influenza (flu)

Question 16

What is tuberculosis?

Answer 16

A bacterial disease of humans, pigs, cows, badgers and deers, commonly caused by bacterium tuberculosis

Question 17

What damage does TB cause?

Answer 17

• Damages and destroys lung tissues

* Surpresses immune system, so the body is more vulnerable to other diseases

Question 18

How has a rise in HIV allowed TB to spread?

Answer 18

People with HIV are more likely to be infected by TB

Question 19

How can the spread of TB be controlled?

Answer 19

TB can be cured with antibiotics

TB is preventable by improving living standards and through vaccination

Question 20

What is bacterial meningitis?

Answer 20

A bacterial infection of the brain’s meninges (the protective layers of the brain’s surface)

Question 21

How does bacterial meningitis cause damage?

Answer 21

Bacterial meningitis can spread to the rest of the body, causing septicemia(blood poisoning) and rapid death

Question 22

What age group does bacterial meningitis commonly affect?

Answer 22

Young children.

Teenagers 15-19

Question 23

What symptom of septicemia means immediate medical treatment is needed?

Answer 23

When a red rash is pressed and doesn’t ‘disappear’

Question 24

What % of people infected with septicemia die?

Answer 24

10%

Question 25

What % of people who have recovered from septicemia will have permanent damage?

Answer 25

25%

Question 26

How can the spread of bacterial meningitis be reduced?

Answer 26

Antibiotics can cure the disease in early stages. | Vaccines protect against some forms of bacterial meningitis

Question 27

What is HIV/AIDS?

Answer 27

AIDS is a condition, HIV is a virus. Acquired Immunodeficiency Syndrome (AIDS), caused by HIV (Human immunodeficiency Syndrome), targets T helper cells in the body's immune system.

Question 28

How does HIV/AIDS cause damage?

Answer 28

After targeting the host's immune system, AIDS gradually destroys the immune system, leaving the host more vulnerable to other diseases e.g. TB + pneumonia + some types of cancers

Question 29

What group of organisms does HIV affect?

Answer 29

Humans and other primates

Question 30

Describe what HIV is, relating to its structure.

Answer 30

Retrovirus with RNA as its genetic material.

Question 31

How does HIV work?

Answer 31

* Contains enzyme reverse transcriptase, which transcribes HIV's RNA to a single strand of DNA to produce a single strand of DNA in the host cell. * This DNA interacts with genetic material of the host cell.

Question 32

How is HIV spread?

Answer 32

* Passed from one person to another through bodily fluids, commonly through unprotected sex, shared needles and contaminated blood products. * HIV can also pass from mother to baby during pregnancy, birth or breastfeeding.

Question 33

What is available to reduce the spread of HIV?

Answer 33

There is no cure or vaccine, but anti-retroviral drugs slow the progress of the disease.

Question 34

What traditional practice spreads HIV? Why does this practice spread HIV?

Answer 34

Female genital mutilation - The same equipment used several times can spread infection and women with FGM are more likely to get HIV through intercourse.

Question 35

reserved

Answer 35

reserved

Question 36

What is influenza (flu)?

Answer 36

A viral infection of the ciliated epithelial cells in the gas exchange system.

Question 37

What damage does the flu cause?

Answer 37

Kills ciliated epithelial cells, leaving the airways open to secondary infection.

Question 38

In which people is influenza most likely to be fatal?

Answer 38

Young children, old people and people with chronic illnesses

Question 39

What causes most of the deaths after a person is infected with influenza?

Answer 39

Secondary bacterial infections e.g. pneumonia, on top of the original viral infection

Question 40

What organisms does the flue infect?

Answer 40

Mammals, i.e. human and pigs and birds including chickens

Question 41

What are the 3 main strains of influenza?

Answer 41

A, B and C

Question 42

Which of the influenza strains are the most severe?

Answer 42

Strain A

Question 43

How are strain A influenza viruses classified?

Answer 43

By the proteins on their surface, e.g. A(H1N1) and A(H3N3)

Question 44

How often do flu viruses mutate? How is the extent of this mutation good for us?

Answer 44

Regularly - however, the changes are small, so having flu one year leaves you with immunity for the next

Question 45

Why do flu pandemics occasionally occur?

Answer 45

Rarely, there is a major change in influenza's surface antigens. This means there are no antibodies available to quickly eliminate it.

Question 46

How can the spread of flu be limited?

Answer 46

Vulnerable groups of people are given annual vaccines against changing strains. There is no cure.

Question 47

What is malaria caused by?

Answer 47

The protoctista plasmodium.

Question 48

What is malaria spread by?

Answer 48

Infected female anopheles mosquitoes.

Question 49

What are the 2 hosts which are a part of plasmodium's life cycle?

Answer 49

People and mosquitoes

Question 50

What is the life cycle of plasmodium?

Answer 50

Reproduce inside female mosquito. | Female mosquito requires 2 blood meals before laying eggs - this is when plasmodium is passed on to people.

Question 51

What does the plasmodium do?

Answer 51

Plasmodium invades erythrocytes, the liver and the brain.

Question 52

What is the consequence of malaria recurring?

Answer 52

Makes the host weak and more vulnerable to other infections

Question 53

How can malaria be treated?

Answer 53

No vaccine and limited cure.

Question 54

How can the spread of malaria be limited?

Answer 54

Through preventative measures - these are very effective. | The key is to control the vector.

Question 55

Explain what the preventative measures to malaria are.

Answer 55

Anopheles mosquitoes can be eliminated through: Insecticides Removing standing water, which they need to reproduce Mosquito nets, window+door screens and long sleeved clothing prevent mosquitoes biting.

Question 56

What is ring worm?

Answer 56

A fungal disease

Question 57

What organisms does ring worm affect?

Answer 57

Mammals i.e. cattle, dogs, humans

Question 58

Is ring worm the same in all infected organisms?

Answer 58

No - different fungi infect different species

Question 59

What are the symptoms of ring worm in cattle?

Answer 59

Grey-white, crusty, infectious, circular areas on skin. | Not damaging but may be itchy.

Question 60

How do you cure ring worm in cattle?

Answer 60

By using antifungal creams

Question 61

What is athlete's foot?

Answer 61

A human fungal disease caused by Tinia pedia - human form of ring worm

Question 62

What does athlete's do?

Answer 62

Grows on and digests the warm, moist skin between toes

Question 63

What damage does athlete's foot do?

Answer 63

Athlete's foot causes cracking and scaling, which is itchy and sore

Question 64

How can athlete's foot be treated?

Answer 64

Through antifungal cream