3. Infection and Response

Question 1

What is a pathogen?

Answer 1

A microorganism that can cause disease.

Question 2

Pathogens are microorganisms that can cause disease. Are these diseases classed as communicable or non-communicable diseases?

Answer 2

Communicable diseases.

Question 3

Can pathogens can infect both animals and plants?

Answer 3

Yes.

Question 4

Give three ways we can reduce the spread of infectious disease.

Answer 4

1. Improved hygiene, such as washing hands and cleaning surfaces.
2. Killing the vectors that carry pathogens.
3. Vaccination.

Question 5

Are viruses living organisms?

Answer 5

No

Question 6

Are viruses made of cells?

Answer 6

No

Question 7

How can measles be spread between people?

Answer 7

Via droplets in air when an infected person coughs or sneezes.

Question 8

What are the symptoms of measles?

Answer 8

1. Red skin rash.
2. Fever (feeling hot and cold).

Question 9

Which two ways can HIV be spread between people?

Answer 9

1. Sexual contact
2. Exchange of bodily fluids

Question 10

What is the treatment for HIV/AIDS?

Answer 10

Antiretroviral drugs

Question 11

What type of organism does Tobacco Mosaic Virus (TMV) infect?

Answer 11

Plants

Question 12

What is the main symptom of Tobacco Mosaic Virus (TMV)?

Answer 12

Patches of the leaves get discoloured

Question 13

Tobacco Mosaic Virus (TMV) reduces the amount of photosynthesis that a plant can do. What are the consequences of this?

Answer 13

1. The plant won’t be able to produce as many sugars.
2. The plant won’t be able to grow as well.

Question 14

Are bacteria unicellular (made of a single cell) or multicellular (made of many cells)?

Answer 14

Unicellular

Question 15

Gonorrhoea is an STD transmitted by sexual contact (such as unprotected sex). What are the symptoms of gonorrhoea?

Answer 15

1. Pain when urinating.
2. Yellow/green discharge from the vagina or penis.

Question 16

What is the treatment for gonorrhoea?

Answer 16

Antibiotics such as penicillin

Question 17

Are fungi unicellular, multicellular, or can they be either?

Answer 17

Can be either

Question 18

How does skin help to defend against disease?

Answer 18

1. It covers the body, physically preventing pathogens from entering.
2. It secretes oils and antimicrobial substances that kill pathogens.

Question 19

The nose has hairs inside it that act as a physical barrier to pathogens. What are the hairs in the nose coated with to catch pathogens?

Answer 19

Mucus.

Question 20

The cells that line the trachea, bronchi and bronchioles have tiny hair-like projections that waft the mucus and pathogens away from the lungs.
What are these structures called?

Answer 20

Cilia.

Question 21

What substance does the stomach produce to kill pathogens?

Answer 21

Hydrochloric acid

Question 22

What is the role of the immune system?

Answer 22

To locate and destroy pathogens that enter the body.

Question 23

What are the functions of white blood cells?

Answer 23

1. Phagocytosis
2. Produce antitoxins
3. Produce antibodies

Question 24

What do antitoxins do?

Answer 24

Bind and neutralise the toxins produced by bacteria

Question 25

What does a vaccine contain?

Answer 25

Small quantities of dead, weakened, or inactive forms of a pathogen

Question 26

How do vaccines work?

Answer 26

They expose us to the antigens of a pathogen so that we can develop immunity to it.

Question 27

What are the potential drawbacks of vaccines?

Answer 27

1. They can cause mild symptoms such as fever or a sore arm 2. They don't always give full immunity to the disease 3. They can (in rare cases) cause severe reactions such as seizures.

Question 28

Do painkillers help to cure the underlying disease?

Answer 28

No

Question 29

Which type(s) of organisms can antibiotics kill?

Answer 29

Bacteria.

Question 30

What could help reduce the spread of antibiotic resistance?

Answer 30

1. Patients taking antibiotics for the full prescribed course. 2. Doctors only prescribing antibiotics for serious bacterial infections.

Question 31

How do antibiotics help to cure bacterial infections?

Answer 31

They directly kill bacteria cells.

Question 32

What does the term 'efficacy' mean?

Answer 32

How well a drug produces the desired effect.

Question 33

What does the term 'toxicity' mean?

Answer 33

How harmful a drug is e.g. how many side effects

Question 34

What does the term 'dosage' mean?

Answer 34

How much of the drug is required to give the desired effect.

Question 35

Why is it important that new medicinal drugs undergo testing before they are used?

Answer 35

1. To make sure they are an effective treatment. 2. To determine the optimum dose 3. To make sure they are safe to use.

Question 36

In a double blind trial, who knows who is given the trial drug, and who is given the placebo?

Answer 36

Only the researcher

Question 37

What is a placebo?

Answer 37

A substance or treatment that contains no active drug.