Infection and response

Question 1

What are communicable diseases spread by?

Answer 1

Pathogens

Pathogens are microorganisms that can cause diseases.

Question 2

What are the types of pathogens?

Answer 2

• Bacteria
• Viruses
• Fungi
• Protists

These microorganisms are responsible for various diseases.

Question 3

How do bacteria reproduce and affect the body?

Answer 3

They reproduce inside the body and produce toxins that make us feel ill.

Question 4

How do viruses reproduce and affect cells?

Answer 4

They reproduce inside cells causing damage to the cell and making us feel ill.

Question 5

Name two viral diseases in animals.

Answer 5

• Measles
• HIV

Tobacco mosaic virus is an example of a viral disease in plants.

Question 6

Name two bacterial diseases.

Answer 6

• Salmonella
• Gonorrhoea

Question 7

What is rose black spot?

Answer 7

A fungal disease affecting plants.

Question 8

What causes malaria?

Answer 8

A protist that is spread by mosquitos.

Question 9

What are the non-specific defences of the human body?

Answer 9

• Skin
• Nose
• Stomach acid
• Cilia and mucus

Question 10

How does the immune system defend against pathogens?

Answer 10

Using white blood cells.

Question 11

What are the three ways white blood cells defend against pathogens?

Answer 11

• Phagocytosis
• Antitoxin production
• Antibody production

Question 12

What do vaccines contain?

Answer 12

Dead or weakened pathogens.

Question 13

How do vaccines prevent illness?

Answer 13

By causing a more rapid immune response to pathogens.

Question 14

How can the transmission of pathogens be reduced?

Answer 14

By immunising a large proportion of the population.

Question 15

What do painkillers do?

Answer 15

Treat the symptoms of illness but do not kill pathogens.

Question 16

What do antibiotics do?

Answer 16

Kill bacteria.

Question 17

Do antibiotics kill viruses?

Answer 17

No, because the virus is inside the cell.

Question 18

From what sources are new drugs extracted?

Answer 18

Plants and microorganisms.

Question 19

What is the heart drug ‘Digitalis’ derived from?

Answer 19

Foxgloves.

Question 20

What is the painkiller ‘Aspirin’ derived from?

Answer 20

The willow tree.

Question 21

Where does penicillin come from?

Answer 21

Penicillium mould.

Question 22

What must new medical drugs undergo before use?

Answer 22

Testing in trials to check safety, effectiveness, and dosage.

Question 23

What is preclinical testing?

Answer 23

Testing done in the lab using cells, tissues, and animals.

Question 24

How are clinical trials conducted?

Answer 24

First on healthy volunteers and then on patients.

Question 25

What methods are used to reduce bias in clinical trials?

Answer 25

* Placebos * Double blind trials

Question 26

What are monoclonal antibodies?

Answer 26

Produced from a single cell clone.

Question 27

What do monoclonal antibodies specifically bind to?

Answer 27

One shape of antigen.

Question 28

How are monoclonal antibodies made?

Answer 28

Using mouse lymphocytes and tumour cells to create hybridoma cells.

Question 29

What are hybridoma cells used for?

Answer 29

To produce the same antibody that can be collected and purified.

Question 30

List some uses of monoclonal antibodies.

Answer 30

* Pregnancy tests * Locating specific cells or tissues * Cancer treatments

Question 31

What are some plant defences?

Answer 31

* Thick cell walls * Waxy cuticle on leaves * Antibacterial chemicals * Poisons to deter herbivores * Leaves which droop * Mimicry * Thorns and hairs

Question 32

How can plant diseases be detected?

Answer 32

* Stunted growth * Spots or discolouration * Decay * Growth or malformed stems * Presence of pests

Question 33

What can a lack of nitrate ions lead to in plants?

Answer 33

Stunted growth.

Question 34

What does a lack of magnesium ions cause in plants?

Answer 34

A lack of chlorophyll.

Question 35

What are physical plant defence responses?

Answer 35

* Cellulose cell walls * Tough waxy cuticle * Layers of dead cells (bark)

Question 36

What are chemical plant defence responses?

Answer 36

* Antibacterial chemicals * Poisons

Question 37

What are examples of mechanical adaptations in plants?

Answer 37

* Thorns and hairs * Leaves which droop or curl * Mimicry