B3 Viral, Fungal and Protist Diseases (page 44)

Question 1

What Three Viral Diseases do you need to learn about?

Answer 1

Measles
HIV/AIDS
Tobacco mosaic virus (TMV)

(there are heaps of diseased cause by these, but you need to know about these ones).

Question 2

What is Measles?

Answer 2

It is a viral disease.

Question 3

How do measles spread?

Answer 3

by droplets from an infected person’s sneeze or cough.

Question 4

What symptoms do you get when measles develop?

Answer 4

a red skin rash,
fever (high temperature)

Question 5

Is measles a serious virus?

Answer 5

yes, very serious, or even fatal, if there are complications

for example, measles can sometimes lead to pneumonia (a lung infection), or inflammation of the brain (encephalitis).

Question 6

Can you get vacinated against measles?

Answer 6

yes, most people are vacinnated against measles when they’re young.

Question 7

What is HIV?

Answer 7

HIV (Human Immunodeficiency Virus) is a virus. The virus atacks the immune cells.

Question 8

How do HIV (Human Immunodeficiency Virus) spread?

Answer 8

it is spread by sexual contact, or by exchangng bodily fulids, such as blood.

(this can happen when people share needles when taking drugs).

Question 9

What are the symptoms of HIV (Human immunodeficiency Virus)?

Answer 9

initially it causes flu-like symptoms for a few weeks. Usually the person doesn’t then experience any symptoms for several years.

Question 10

How can HIV (Human immunodeficiency Virus), be treated?

Answer 10

it can be controlled with antiretroviral drugs. These stop the virus replicating in the body.

Question 11

Is HIV a serious virus and why?

Answer 11

Yes, if the body’s immune system is badly damaged, it can’t cope with other infections or cancers. At this stage, the virus is known as late stage HIV infection or AIDS (Acquired Immunodeficiency Syndrome).

Question 12

What is Tobacco Mosaic Virus (TMV)?

Answer 12

a virus that affects many species of plants.

e.g. tomotoes.

Question 13

How do Tobacco Mosaic Virus (TMV) spread?

Answer 13

it causes a mosaic pattern on the leaves of the plants - parts of the leaves become discoloured.

Question 14

What happens to the plants leaves, if Tobacco Mosaic Virus (TMV) discolours the plants leaves?

Answer 14

The discolouration means the plant can’t carry out photosynthesis as well, so the virus affects growth.

Question 15

Why is Photosynthesis important for plant growth?

Answer 15

because it produces glucose (see page 50).

Question 16

What is Rose Black Spot?

Answer 16

it is a fungus that causes purple or black spots to develop on the leaves of rose plants.

Question 17

What happens to the leaves of roses if a Rose plant has Rose Black Spot?

Answer 17

The leaves can turn yellow and drop off.

Question 18

What happens if the Rose leaves drop off?

Answer 18

this means that less photosynthesis can happen, so the plant doesn’t grow very well.

Question 19

How do Rose Black Spot fungus spread?

Answer 19

it spreads through the environment in water or by the wind.

Question 20

How can Gardeners treat Rose Black Spot?

Answer 20

Gardeners can treat the disease using fungicides and by stripping the plant of its affected leaves. The leaves then need to be destroyed so that the fungus can’t spread to other rose plants.

Question 21

What is fungicides?

Answer 21

a chemical that destroys fungus.

Question 22

What is Malaria?

Answer 22

it is caused by a Protist (protists are singled-celled eukaryotes)

Part of the Malarial Protist’s life cycle takes place inside the mosquito.

Question 23

How is Marlaria spread?

Answer 23

part of the malarial protist’s life cycle takes place inside the mosquito. The mosquitoes are vectors (an insect that carries the protist), they pick up the malarial protist when they feed on an infected animals. Everytime the mosquito feeds on another animal, it infects it by inserting the protist into the animal’s blood vessels.

Question 24

Is Malaria serious?

Answer 24

Yes, it causes repeating episodes of fever. It can be fatal.

Question 25

How can Malaria be reduced?

Answer 25

by stopping the mosquitoes from breeding,

Question 26

How can people protect themselves from mosquitoes?

Answer 26

by using insecticides and mosquito nets.

Question 27

What symptom of measles is shown on the skin?

Answer 27

a red skin rash. (1 mark)

Question 28

How can Rose Black Spot be treated so that it doesn’t spread to other plants?

Answer 28

Using a fungicide (1 mark), and by stripping the plants of the affected leaves and destroying them (1 mark).