Topic 3 - Infection and Response

Question 1

Why are bacteria cells so effective?

Answer 1

They can reproduce rapidly within the body

Question 2

How do bacteria damage you?

Answer 2

They make you feel ill by producing toxins that damage cells and tissues

Question 3

How do virus’ work?

Answer 3

They live inside cells and replicate themselves using cell’s machinery to make copies

Question 4

What happens when the cell is full of virus’?

Answer 4

It bursts and releases them into the body

Question 5

What makes you feel ill when you have a virus?

Answer 5

Cell damage

Question 6

What are protists and what do they do?

Answer 6

They are single celled eukaryotes and they live on or inside organisms, they cause those organisms damage

Question 7

How can diseases be transferred?

Answer 7

1. Vectors
2. Physical contact
3. Bodily fluids

Question 8

How do fungi work and cause disease?

Answer 8

They have hyphae (thread like structures) that can penetrate skin and the surface of plants, some have spores which then spread to others organisms

Question 9

Measles

Answer 9

Spread: Droplets
Type of disease: Virus
Symptoms: Red skin rash, fever
Treatment: Vaccination

Question 10

HIV

Answer 10

Spread: Sexual contact or bodily fluids
Type of disease: Virus
Symptoms: Flu-like symptoms
Treatment: Antiretroviral drugs

Question 11

Tobacco Mosaic Virus

Answer 11

Spread: Physical contact
Type of disease: Virus
Symptoms: Leaves become discoloured
Treatment: N/A

Question 12

Malaria

Answer 12

Spread: Vector
Type of disease: Protist
Symptoms: Repeating episodes of fever
Treatment: Insecticides and mosquito nets

Question 13

Salmonella

Answer 13

Spread: Ingesting infected food
Type of disease: Bacteria
Symptoms: Fever, stomach cramps, vomiting, diarrhoea
Treatment: Vaccinating food and proper preparation

Question 14

Gonnorehea

Answer 14

Spread: STD
Type of disease: Bacteria
Symptoms: Pain when urinating and thick yellow or green discharge
Treatment: Antibiotic (penicillin)

Question 15

How can you prevent the spread of disease?

Answer 15

1. Being hygienic
2. Destroying vectors
3. Isolating infected individuals
4. Vaccinations

Question 16

List some aspects of your body’s defence system

Answer 16

1. Skin acts as a barrier
2. Hairs and mucus trap particles containing pathogens
3. Trachea and bronchi secrete mucus to trap pathogens, cilia then wafts mucus to throat to be swallowed
4. The stomach has HCl acid to kill pathogens

Question 17

What is phagocytosis?

Answer 17

The process of white blood cells engulfing pathogens

Question 18

What do antibodies do?

Answer 18

Antibodies are produced by white blood cells to lock onto antigens so that other white blood cells can find them and destroy them, they are specific to one type of antigen and won’t lock onto others

Question 19

What do antitoxins do?

Answer 19

Counteract toxins produced by invading bacteria

Question 20

How do vaccinations work?

Answer 20

They allow the body to start producing antibodies before you get infected with the antigen so they can be prepared and kill them immediately

Question 21

What are the advantages of vaccinations?

Answer 21

1. Help control communicable diseases

2. Large outbreaks of disease don’t affect anything so long as majority of the population is vaccinated

Question 22

What are the disadvantages of vaccinations?

Answer 22

1. They don’t always work

2. You can have a bad reaction

Question 23

Why is it hard to develop drugs to kill virusses?

Answer 23

They reproduce inside your cells so you cannot necessarily target the virus without hitting the cell as well

Question 24

What is the problem with antibiotics?

Answer 24

If they are used too much a strain of bacteria can become resistant to it and they no longer work

Question 25

Why do many drugs come from plant?

Answer 25

They have developed their own defence systems which we can then use and replicate

Question 26

What other sources can produce drugs?

Answer 26

Microorganisms .e.g. penicillin was grown from mould

Question 27

What are the three stages in drug testing?

Answer 27

1. Preclinical testing done on cells or tissues in labs - they test for affect on systems
2. Preclinical testing done on live animals - these test for efficacy, toxicity and dosage
3. Clinical trial done on humans - tested on healthy volunteers, usually in a double blind trial, to find the correct dosage (higher efficacy, lowest toxicity)

Question 28

Why do results from trials go through peer reviews?

Answer 28

This prevents forgery

Question 29

What type of white blood cell produce antibodies?

Answer 29

B-lymphocytes

Question 30

What is a hybridoma?

Answer 30

A B-lymphocyte cell fused with a tumour cell

Question 31

Why are hybridomas helpful?

Answer 31

B-lymphocytes don’t grow easily so you can fuse them with a rapidly dividing tumour cell to form a hybridoma; this hybridoma can then divide quickly to produce more and then the antibodies can be collected and purified

Question 32

Give one use for monoclonal antibodies

Answer 32

Pregnancy tests - if you wee on the stick and you are pregnant then the hormone binds to the antibodies on the blue beads, these are carried up the stick to the bit you see where they stick to the antibody making it show up blue, if you are not pregnant they don’t bond and keep on moving up

Question 33

How can monoclonal antibodies be used to treat cancer?

Answer 33

You can attach an anti-cancer drug to a monoclonal antibody which will then be injected into a patient using a drip, the antibody targets the cancer cells and attaches to the tumour marker on it, then the anti-cancer drug can kill the cancer cells without affecting the normal cells around it

Question 34

What is a problem with monoclonal antibodies?

Answer 34

They can cause some serious side effects and make patients feel very sick