Infection and response

Question 1

Define non-communicable and communicable disease.

Answer 1

Non-communicable: It’s not caused by pathogens and it’s not passed on from person to person

Communicable: It’s caused by pathogens and spread from person to person.

Question 2

Define pathogens

Answer 2

Pathogens are microorganisms that enter the body and causes illness and diseases.

Question 3

What is bacteria and how does it make you feel ill?

Answer 3

They are really small cells which reproduce rapidly in our bodies and makes us feel ill by producing toxins that damages the cells and tissues.

Question 4

What is a virus and how does it make us feel ill?

Answer 4

Viruses are not cells but are also really tiny and can reproduce.
* They are able to live inside the cells and replicate themselves.
* Due to that the cell bursts and releases new viruses into our body and damages the cells, making us feel ill.

Question 5

What is protist and how does it make us feel ill?
What is a vector?

Answer 5

They are eukaryotes and single celled.
* Some protists are parasites that live on or inside other organisms and damages them.
* These are often transferred to other organsims by a vector.

Vector is an organism that doesn’t cause the disease itself but spreads the infection.

Question 6

What is fungi and how does it make us feel ill?

Answer 6

• Some are single-celled
• Other are made up of hyphae (thread like structure)
• The hyphae can grow and penetrate human skin and the surface of plants which causes diseases
• They can also produce spores that are able to spread to other plants and animals.

Question 7

In what ways can pathogens spread?

Answer 7

• Water: drinking or bathing in dirty water, causing cholera
• Air: pathogens are carried in the air and breathed in causes disease as the airborne pathogens are carried in the air as droplets.
• DIrect contact: touching contaminated surfaces including skin.

Question 8

1) What type of pathogen disease is measles?
2) How is it spread?
3) Name 2 symptoms.
4) How is it treated?

Answer 8

1) Viral disease
2) Inhaling droplets from an infected person’s sneezes and coughs.
3) Symptoms:
* fever
* red skin rash

4) Vaccinations at young age

Question 9

What is measles a risk factor of?

Answer 9

• Death, due to complications
• Pneumonia
• Brain infection

Question 10

1) What type of pathogen disease is rose black spot?
2) How is it spread and what affect does it have on the plant?
3) Name 2 symptoms.
4) How is it treated?

Answer 10

1) Fungal disease
2) It’s spread through the environment through water and wind. This disease leads to less photosynthesis, meaning the plants can’t grow properly or healthily.
3) Symptoms:
* purple or black spots on leaves
* leaves turn yellow and drop off

4) Treated by using fungicides and stripping the affected leaves from the plants

Question 11

1) What type of pathogen disease is HIV?
2) How is it spread and what does it do to the body?
3) Name 2 symptoms.
4) How is it treated?

Answer 11

1) Viral disease
2) Spread by sexual contact, exchange of bodily fluids or sharing needles.
This disease attacks the immune system.
3) Symptoms:
* a flue like illness for few weeks

4) it’s controlled by antiretrovial drugs which stops the virus from replicating in the body.

anti-ret-rovial

Question 12

What is it called if the immune system is badly damaged by HIV that it can’t cope with any other infections?

Answer 12

Late stage HIV infection / AIDS

Question 13

1) What type of pathogen disease is malaria?
2) How is it spread
3) Name a symptom.
4) How can the spread of malaria be stopped?
5) How can humans be protected from it?

Answer 13

1) Protist disease
2) Spread by being bitten by an infected mosquito as it’s a vector.
3) Symptoms:
* repeating episodes of fever , can be fatal

4) It can be reduced by preventing the mosquitos (vectors) from breeding.
5) Humans are protected by insecticides and mosquito nets.

Question 14

1) What type of pathogen disease is salmonella?
2) How is it spread?
3) Name 2 symptoms.
4) How is it prevented?

Answer 14

1) Bacterial disease, causing food poisoning
2) Consuming food that’s contaminated by salmonella, mainly from poultry which may have got the disease while it was alive or it was prepared in unhygienic conditions.
3) Symptoms:
* fever
* abdominal cramps
* vomiting
* diarrhoea

4) It’s prevented by giving poultry vaccionations against Salmonella

Question 15

1) What type of pathogen disease is tobacco mosaic virus (TMV)?
2) How is it spread and how does it affect the growth of the plants?
3) Name 2 symptoms.
4) How is it controlled?

Answer 15

1) Viral disease affect different types of plants like tomatoes
2) It’s spread when infected leaves are rubbing against healthy plants, contaminated tools or the workers hands (which can be infected by cigarettes).
The discolouration of the leaves doesn’t allow photosynthesis to be carried out properly which affect the rate of growth.
3) Symptoms:
* mosaic pattern on the leaves
* part of the leaves become discoloured

4) The workers should wash their hands after touching contaminated plants
Wash the tools
Dig up and destroy infected plants

Question 16

1) What type of pathogen disease is gonorrhoea?
2) How is it spread?
3) Name 2 symptoms.
4) How is it treated?
5) Why is penicillin not used to treat this anymore?

Answer 16

1) Bacterial disease
2) It’s spread by sexual contact; unprotected sex
3) Symptoms:
* Pain while they urinate
* a thick yellow or green discharge from the vagina or penis

4) Can be treated with anitobiotics and using contraception.
5) The strains of this bacteria have become resistent to this, which is why it’s trickier to treat it with this.

Question 17

What are the 4 fours of preventing the communicable diseases?

Answer 17

• Being hygienic
• Destroying the vectors by damaging their habitat or using insecticides
• Isolating infected individuals
• Vaccination

Question 18

Define painkiller

Answer 18

A drug (aspirin) that relieves the pain and reduces symptoms but doesn’t kill the pathogens.

Question 19

Name the four primary defence system of the body that prevents pathogens entering our bodies.

Answer 19

• Skin - it’s a complete barrier against pathogens that produces antimicrobial substances to kill pathogens.
• Nasal hair - keeps dust and larger microorganisms out, and produces mucus which helps to trap pathogens.
• Trachea and bronchi - they produce mucus to catch pathogens and are lined with cilia (hair). The cilia passes the mucus to the back of the throat so it can be swallowed.
• Hydrochloric acid - produced by the stomach to kill any pathogens that have entered the body.

Question 20

What are two types of white blood cells?

Answer 20

Lymphocyte
Phagocyte

Question 21

How does phagocytosis defend the body against pathogens?

Answer 21

1) The phagocytes identify the pathogens and attaches itself to it.
2) The cytoplasm surrounds and engulfs the pathogen
3) The pathogen is killed and digested
4) Indigestible residue is removed.

Question 22

How does antibody production helps to defend against pathogens?

Answer 22

1) Pathogens contain antigens on their surface
2) The lymphocytes detect the antigens and produce the antibodies in response (which are specific to that type of antigens and won’t lock onto any other one).
3) The antibodies lock onto the antigens, causing the pathogens to be destroyed.
4) If you come in contact with the same pathogens, your body’s memory cells can produce a quicker response by producing the antibodies quick.

Question 23

How does the antitoxin production helps to defend against pathogens?

Answer 23

1) Bacteria can produce harmful toxins in the body
2) Lymphocytes release antitoxins which are specific to the toxins.
3) The antitoxins lock onto the toxins and neutralise them.

Question 24

What does a vaccine contain?

Answer 24

Small amounts of dead or inactive pathogens injected in the body; not harmful.

Question 25

Explain how a vaccination makes a person immune from a disease.

Answer 25

Vaccines contain dead forms of pathogens and after injecting them, they stimulate the white blood cells to produce antibodies. The antibodies destroy the pathogens and protects us from them.

Question 26

Why are vaccines important?

Answer 26

They prevent the chances of getting the disease later in life and reduces the chances of spreading it from generation to generation.

Question 27

What are the advantages and disadvantages of vaccines?

Answer 27

Advantages:
* They have helped lots of communicable diseases that were once common - smallpox no longer occurs and polio has fallen by 99%
* Big outbreak of disease called epidemics can be prevented if large percentage of population is vaccinated, meaning even the people who aren’t vaccinated are unlikely to get the disease as there are less people who can pass on the disease.

Disadvantages:
* They don’t always work and sometimes don’t even give you immunity
* You may have a bad reaction to a vaccine such as swelling or fever; but this is rare.

Question 28

Define immunity

Answer 28

It’s the protection from pathogens and it prevents you from getting the disease.

Question 29

What are the 3 things doctor’s consider before prescribing drugs to patients?
Why are they important?

Answer 29

• Efficacy - means how well the drug works.
  Doctors need to know how well it works to cure a disease to improve the symptoms.
• Toxicity - means how harmful the drug is.
  Some drugs are toxic and have side effect which may be harmful for some people.
• Dosage - means how much of the drug should be given.
  If too much is given, it can be toxic and negatively impact patients health.

Question 30

What are the 5 stages of drug development?

Answer 30

1) Drugs are tested using computer models and human cells in the lab.
Many substances fail as they damage the cells.

2) Animal testing - to monitor any side effects

3) Drugs are tested on healthy volunteers to find out if they’re safe at low dose, and what side effects it may have, if any.

4) Drugs are tested on people with illness to ensure they are safe and they work.

5) After all successful stages, drug companies receive approval to mass produce the drug.

Question 31

What is a placebo?

Answer 31

A drug that does not contain the real drug.

Used in human trials.

Question 32

What are antibiotics?

Answer 32

Penicillin - they kill / prevent the growth of bacteria without killing the body cells.
It’s important that right antibiotic is taken as different types treat different types of bacteria.

Question 33

Why can’t antibiotics kill viruses?

Answer 33

They don’t work against viruses as they reproduce using the body cells, making it difficult for antibiotics to just kill the virus without killing body cells.

Question 34

How does bacteria become resistant to antibiotics?
Explain what happens if you get an infection.
What do the resistant strains of the bacteria do to your body?

Answer 34

Bacteria can mutate which makes it resistant to an antibiotic.

When you get an infection, some bacteria might be resistant to antibiotics and only the non-resistant strains of bacteria gets treated and killed.
The resistant strains of bacteria survive and reproduce, making the population increase.

Question 35

What is aspirin used to do?
Where was the chemical found?

Answer 35

Aspirin is used as painkiller and to lower fever.
It’s developed from a chemical in willow.

Question 36

What is digitalis used for?
Where was the chemical found?

Answer 36

It’s used to treat heart conditions.
It’s developed from a chemical found in foxgloves.

Question 37

How was penicillin discovered?

Answer 37

Fleming was clearing out some petri dish containing bacteria, and he noticed one of them had mould on the dish with area around it being free of bacteria.
The mould produced a substance that killed bacteria; the mould was penicillin.