biology 5

Question 1

What is a communicable disease?

Answer 1

a disease that can be transmitted from one organism to
another

Question 2

What is a pathogen?

Answer 2

a microorganism that causes disease

Question 3

Name four types of pathogen.

Answer 3

bacteria, fungi, protists, viruses

Question 4

How can pathogens spread?

Answer 4

air, water, direct contact

Question 5

How do bacteria make you ill?

Answer 5

produce toxins that damage tissues

Question 6

How do viruses make you ill?

Answer 6

live and reproduce rapidly within body cells, damaging or destroying them

Question 7

Name three examples of viral diseases.

Answer 7

measles, HIV, tobacco mosaic virus

Question 8

Name two examples of bacterial diseases.

Answer 8

Salmonella, gonorrhoea

Question 9

Name four methods of controlling the spread of
communicable disease.

Answer 9

good hygiene, isolating infected individuals, controlling
vectors, vaccination

Question 10

Describe an example of a protist disease.

Answer 10

malaria – caused by a protist pathogen that is spread
from person to person by mosquito bites, and causes
recurrent fevers

Question 11

Describe an example of a fungal disease in plants.

Answer 11

rose black spot – spread by water and wind, and
affects plant growth by reducing a plant’s ability to
photosynthesise

Question 12

How can the cause of a plant disease be identified?

Answer 12

gardening manuals and websites, laboratory testing,
monoclonal antibody kits

Question 13

How can plant diseases be detected?

Answer 13

areas of decay, discolouration, growths, malformed
stems or leaves, presence of pests, spots on leaves, and
stunted growth

Question 14

explain how coughing and sneezing can cause viruses to spread

Answer 14

droplets from the infected person are released and inhaled into the lungs then the immune system

Question 15

explain one way the body is adapted to prevent cold and flu viruses entering the body

Answer 15

• The nose has internal hairs, which act as a physical barrier to infection. Cells in the nose produce mucus. which traps pathogens before they can enter the lungs. When the nose is blown, the mucus, and any pathogens that are trapped within it, is removed.

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Question 16

describe the 3 roles of white blood cells in preventing disease

Answer 16

• PRODUCING ANTIBODIES —> produce special chemicals called antibody’s, these target particular bacteria or viruses and damages them.You need a specific antibody for each type of pathogen.Once your white blood cells have produced antibodies once again against a particular pathogen, they can be made very quickly if that pathogen gets in the body again.
• PRODUCING ANTITOXINS —> produce antitoxins which counteract(cancel out) the toxins(poisons) released by pathogens
• INGESTING MICROORGANISMS —> Phagocytes are a type of white blood cell that move by amoeboid action. They send out pseudopodia which allows them to surround invading microbes and engulf them. Phagocytes release digestive enzymes which break down the trapped microbes before they can do any harm. This process is called phagocytosis