Fighting Disease

Question 1

What are the two main types of pathogen?

Answer 1

Bacteria

Virus

Question 2

What are bacteria?
How big are they?
What do they do inside your body?

Answer 2

Very small living cells
1/100th of the size of a normal body cell
Reproduce rapidly

Question 3

How do bacteria make you feel ill?

Answer 3

Damage your cells
Produce toxins (poisons)

Question 4

Viruses are not …

How small are they in comparison to bacteria?

Answer 4

cells

1/100th of the size or a bacterium

Question 5

How do viruses replicate themselves?
What then happens to the cell?
What makes you feel ill?

Answer 5

They invade your cells and using the cells machinery, produce many copies of themselves.
It bursts releasing all the viruses
The cell bursting

Question 6

What three things stop microorganisms getting into your body?

Answer 6

Skin
Hairs
Mucus in the respiratory tract

Question 7

How does the body stop microorganisms getting into the blood through cuts?

Answer 7

Platelets (fragments of cells) help blood to clot quickly to seal wounds.

Question 8

With low numbers of platelets the blood will clot more …

Answer 8

slowly

Question 9

What happens when a microbe gets inside the body?

What is the most important part of this and where does it go inside the body?

Answer 9

The immune system kicks in
The white blood cells
Everywhere, patrolling for microbes

Question 10

What are the three methods WBCells use to fight microbes? (names, no description)

Answer 10

Consuming them
Producing antibodies
Producing antitoxins

Question 11

How do WBCells “consume” microbes to kill them?

2 stages

Answer 11

They engulf the microbe and then digest it

Question 12

How do WBCells kill microbes by producing antibodies?

1. What does every invading microbe have?
2. So what happens when these are detected?
3. What is the key property do these things produced have?
4. What then happens to fight off the microbes?

Answer 12

1. They have antigens, unique molecules on their surface
2. A foreign antigen is detected so the White Blood Cell starts to produce proteins called antibodies that lock onto the cell and kill it.
3. They are specific to that type of antigen so won’t lock onto any others
4. The antibodies are produced rapidly and carried around the body to kill similar bacteria or viruses.

Question 13

What will happen if the person is infected by the same pathogen again?

Answer 13

The WBCells will rapidly produce the antibodies to kill it, the person is naturally immune to that pathogen and won’t get ill.

Question 14

How do WBCells kill microbes with antitoxins?

Answer 14

They produce them and they counter the toxins produced by the invading bacteria.

Question 15

What does a vaccination do?

Answer 15

Protect from future infactions

Question 16

When you’re infected by a new ….. it can take your ….. …. cells a few …. to learn how to deal with it. By this time you can be ….. ……

Answer 16

microbe, white blood cells, days, very ill.

Question 17

What is injected in a vaccination?

What causes your body to produce antibodies to attack them?

Answer 17

Small amounts of dead or inactive microorganisms.

They still have antigens on their surface

Question 18

What does the MMR vaccine contain?

Answer 18

Weakened versions of the viruses that cause measles, mumps and rubella.

Question 19

What does the vaccination cause the next time the body is infected with the same type of microorganism?

Answer 19

White blood cells will RAPIDLY mass-reproduce antibodies to kill of the pathogen

Question 20

What is the problem with some vaccines?

Answer 20

They wear off over time so booster injections are required to boost levels of antibodies.

Question 21

What are the two pros for vaccinations?

1. Pro, two statistics
2. Another pro

Answer 21

They have helped control lots of infectious diseases that were once common in the UK such as tetanus. No smallpox anymore and 99% reduction in polio.
Epidemics can be prevented if a large % of the population is vaccinated, because there are fewer to catch it and spread it.

Question 22

What are the two cons for vaccinations?

Answer 22

They don’t always work - sometimes they don’t give immunity

You can have a bad reaction to a vaccine, swelling or a fever, but bad reactions are rare

Question 23

What do painkillers and lots of drugs do and not do?

Answer 23

Relieve the symptoms and pain, they don’t tackle the CAUSE of the disease.

Question 24

What do antibiotics do?

What is important with these?

Answer 24

They kill or prevent the growth of the bacteria causing the problem without killing body cells
Being treated with the right one as they kill different types of bacteria

Question 25

What do antibiotics not do?

Answer 25

kill viruses

Question 26

Why is it hard to kill viruses?

Answer 26

Because it's hard to find drugs that destroy the virus but not the cell when the viruses are are reproducing inside the cells.

Question 27

What causes bacteria to become resistant to antibiotics? (simple) This means when you're treated for an infection the ..... bacteria will survive.

Answer 27

They can mutate and sometimes these cause them to become resistant to the antibiotic. resistant

Question 28

What happens to resistant bacteria when they survive antibiotics?

Answer 28

They survive and reproduce so the population of resistant bacteria will increase. This is natural selection.

Question 29

What is the problem with a resistant strain of bacteria? | For example....

Answer 29

They can cause a serious infection that can't be treated with antibiotics MRSA which causes serious wound infections is resistant to methicillin

Question 30

How should we slow down the rate of the development of resistant strains of bacteria?

Answer 30

Doctors should avoid over-prescribing antibiotics so they are not given for sore throats etc, only for serious illnesses.

Question 31

How can you test the actions of antibiotics on antibodies?

Answer 31

By growing cultures of microorganisms and then testing their effectiveness

Question 32

What are microorganisms grown in for testing?

Answer 32

A culture medium... usually agar jelly containing carbs, minerals, proteins and vitamins needed to grow.

Question 33

How is a Petri dish set up? What happens after this to put the microorganism on the dish? They then....

Answer 33

Hot agar jelly is poured into the shallow dish, to set. Inoculating loops are used to transfer the microorganisms to the culture medium. ...multiply.

Question 34

What happens to test the antibiotics on an agar jelly dish? Antibiotic resistant bacteria will.... Non-resistant strains will...

Answer 34

Paper disks are soaked in the antibiotic and are placed on the jelly after the microorganisms. .. continue to grow around the disk .... die.

Question 35

Why is equipment sterilized? | Why is it sterilized in the antibiotic test?

Answer 35

To prevent contamination | Unwanted microorganisms could grow in the culture and affect the results

Question 36

How are inoculating loops sterilised? | How are microorganisms prevented from getting into the Petri dish?

Answer 36

They are passed through a flame. | It has an airtight lid which is taped on.

Question 37

Why are the dishes kept at 25 degrees in school labs? | Why are industrial conditions hotter?

Answer 37

Because harmful pathogens are unlikely to grow at this temp | They incubate the bacteria to make them grow faster

Question 38

What did he think doctors were doing? What did Semmelveis do?

Answer 38

Spreading diseases on their unwashed hands. Told them to wash their hands in antiseptic solution cutting the death rate by 10% down to 2% dying.

Question 39

What did Semmelveis's antiseptic solution do? | But what wasn't discovered and what did this mean?

Answer 39

Killed the bacteria on doctors' hands Bacteria hadn't been discovered so he couldn't prove why it worked so when he left the death rates went back up as they stopped

Question 40

What has helped spread MRSA?

Answer 40

Lack of basic hygiene in hospitals

Question 41

How have we coped with bacterial infections in recent decades? But what do bacteria do?

Answer 41

By using antibiotics so the death rate has fallen dramatically Evolve antibiotic resistance e.g MRSA

Question 42

What two things has the over prescription of antibiotics done?

Answer 42

Increased likelihood of people being infected by resistant bacteria Evolved more resistant bacteria called superbugs that are becoming more common

Question 43

What are the 3 dangerous things about bacteria?

Answer 43

They can mutate and produce resistant strains A new strain could be antibiotic resistant so current treatments will now not cure an infection A new strain may be one we haven't previously encountered and so no one would be immune so it could spread rapidly and could cause an epidemic

Question 44

What are the 3 dangerous things about viruses?

Answer 44

They mutate often making it hard to make effective vaccines because changes in their DNA can change their antigens They can evolve quickly to become deadly and infectious like flu viruses Precautions can be taken to stop diseases spreading but many people travel by plane and vaccines and antiviral drugs can be produced but this takes time. A flu pandemic could kill billions all over the world