Topic 3 - Infection + Response (1)

Question 1

What are pathogens?

Answer 1

Microorganisms that enter the body and cause disease

Question 2

What is the namr for the microorganisms that enter the body and cause disease?

Answer 2

Pathogens

Question 3

What type of disease do pathogens cause?

Answer 3

communicable (infectious) diseases - diseases that can easily spread

Question 4

True or False: Both plants and animals can be infected by pathogens

Answer 4

True

Question 5

BACTERIA:
What are bacteria?
How big are they?
How do they make you feel ill?

Answer 5

• Bacterial are very small living cells which reproduce rapidly inside your body
• about 1/100th the size of your body cells
• make you feel ill by producting toxins (poisons) that dammage your cells and tissues

Question 6

VIRUSES:
What are viruses?
How big are they?

Answer 6

• viruses are not cells
• they’re tiny! About 1/100th the size of a bacterium

Question 7

VIRUSES:
How do they replicate themselves?
How do they make you feel ill?

Answer 7

• Like bacteria, they can reproduce rapidly inside your body
• They live inside your cells and replicate themselves using the cells’ machinery to produce many copies of themselves
• The cells will usually then burst, releasing all the new viruses
• This cell damage is what makes you feel ill

Question 8

PROTISTS:
What are prostists?

Answer 8

Protists are single-celled eukaryotes
- there are lots of different types of protists, but they are all eukaryotes (most of them are singe celled)

Question 9

PROTISTS:
What do some prostists take the form of?
How can these infect organisms?

Answer 9

• Some protists are parasites
• Parasites live on or inside other organsims and can cause them damage
• They are often transferred to the organism by a vector, which doesn’t get the disease itself
• e.g. an insect that carries the protist

Question 10

FUNGI:
In what 2 ways can fungi be structured?
How can fungi cause diseases in plants and animals?
How do these diseases spread

Answer 10

• Some fungi are songle-celled, others have a body which is made up od hyphae (thread-like structures)
• the hyphae can grow and penetrate human skin and the surface of plants, causing diseases
• the hyphae can produce spores, whch can be spread to other plants and animals

Question 11

What are the 3 main ways that pathogens can be spread?

Answer 11

• Water
• Air
• Direct Contact

Question 12

How are pathogens spread in water?
Give an example of a disease spread in water?

Answer 12

• some pathogens are picked up by drinking or bathing in dirty water
• cholera is a bacterial infection that’s spread by drinking water contaminated with the diarrhoea of other sufferers

Question 13

What type of disease is cholera?
How is it spread?

Answer 13

• Cholera is a bacterial infection
• It is spread in water by drinking water contaminated with the diarrhoea of other sufferers

Question 14

How are pathogens spread in air?
Give an example of a disease spread in air?

Answer 14

• Pathogens can be carried in the air and then breathed in
• Some airborne pathogens are carried in the air in droplets produced when yu cough or sneeze (the influenza virus that causes flu is spread in this way)

Question 15

How are pathogens spread by direct contact?
Give an example of a disease spread by direct contact?

Answer 15

• Some pathogens can be picked up by touching contaminated surfaces, including the skin
• Athlete’s foot is a fungus that makes the skin itch and flake of - most commonly spread bu touching the same things as an infected person (shower floors and towels)

Question 16

What type of disease is Athlete’s foot?
How is it spread?

Answer 16

• Athletes foot is a fungus which makes the skin itch and flake off
• It’s spreas by direct contact, usually by touching the same things as an infected person (shower floors or towels)

Question 17

Name a disease spread in air?

Answer 17

Influenza virus (that causes flu)

Question 18

Name a disease spread by direct contact?

Answer 18

Athlete’s foot

Question 19

Name a disease spread in water?

Answer 19

Cholera

Question 20

Name 3 viral diseases?

Answer 20

• Measles
• HIV
• Tobacco mosaic virus (TMV)

Question 21

MEASLES:
What type of disease is it?
How is it spread?
What are the common symptoms?
What are the severe symptoms?
How is it treated?

Answer 21

• measles is a viral disease
• spread by droplets of an infected person’s sneeze or cough (air)
• people with measles develop a RED SKIN RASH and they’ll show signs of FEVER (high temperature)
• it can be serious of fatal in therw are complications: can sometimes lead to pneumonia (a lung infection) or inflammation of the brain (encephalitis)
• most people are vaccinated against measles when they’re young

Question 22

HIV:
What type of disease is it?
How is it spread?
What are the initial symptoms?
What are the long term symptoms?
How can the disease be controlled?

Answer 22

• HIV is a viral disease
• it is spread by sexual contact or exchanging bodily fluids such as blood (this can happen when people share needles when taking drugs)
• HIV initially causes flu-like sysmtoms for a few weeks, ususally, the person will then not experience any symptoms for several years
• The virus will attack the immune cells until the body’s immune system is badly damaged and can’t cope with other infections or cancers - at this stage the virus is called late stage HIV infection or AIDS
• HIV can be controlled at the early stages with antiretroviral drugs which stop the virus replication in the body

Question 23

TMV:
What does it stand for?
What type of disease is it?
What does the disease affect?
What are the symptoms?
How fo the symptoms impact the organism?

Answer 23

• tobacco mosaic virus
• it is a viral disease that affects many species of plants like tomatoes
• it causes a mosaic pattern on the leaves of plants - parts of the leaves become discoloured
• the discolouration means that the plant cannot carry out photosynthesis as well, so the virus affects growth (as the plant can’t produce glucose)

Question 24

Name a fungal disease?

Answer 24

Rose black spot

Question 25

ROSE BLACK SPOT? What type of disease is it? What organisms does it affect? What are the symptoms and how do the impact the organism? How does the disease spread and how can the spread be prevented?

Answer 25

- it is a fungus that affects rose plants - it causes purple or black spots to develop on the leaves which then turn yellow and drop off - less photosynthesis can happen so the plant does not grow as well (due to less glucose) - it spreade through the environment by water or wind - gardeners can treat the disease using fungicides and by stripping the plant of its affected leaves (these leaves then need to be destroyed so they can't spread to other rose plants)

Question 26

Name a protist disease?

Answer 26

Malaria

Question 27

MALARIA? What type of disease is it? How does the disease spread? What are the symptoms? How can people protect themselves from malaria?

Answer 27

- Malaria is a protist disease - part of the malarial protist's life cycle takes place inside a mosquito - mosquitoes are vectors, they pick up the malarial protist when they feed on an infected animal - every time the mosquito feeds on another animal, it infects it by inserting the protist into the animal's blood vessels - malaria causes repeated episodes of fever and can be fatal - the spead of malaria can be reduced by stopping the mosquitoes from breeding - people can also be protected from mosquitoes using insectisides and mosquito nets

Question 28

Name 2 bacterial diseases?

Answer 28

- salmonella - gonorrhoea

Question 29

SALMONELLA: What type of disease is it? What are the common symptoms? What causes the symptoms? How does it spread? How is the disease controlled?

Answer 29

- salmonella is a bacterial disease that causes food poisoning - symptoms include fever, stomach cramps, vomiting and diarrhoea - these symptoms are caused by toxins that the bacteria produce - you can get salmonella food poisoning by eating food that has beeen contaminated with Salmonella bacteria, e.g. eating chicken that caught the disease whilst it was alive, or eating food that has been contaminated by being prepared in unhygienic conditions - In the UK, most poultry (e.g. chickens and turkeys) is given a vaccination against salmonella - this controls the spread of the disease

Question 30

GONORRHOEA: What 2 types of disease is it? How is it spread? What are the common symptoms? How is it treated? How can the spread be prevented?

Answer 30

- it is a sexually transmitted disease caused by bacteria - STDs are passed on by sexual contact, e.g. having unprotected sex - symptoms include infected people experiencing pain when they urinate or thick yellow or green discharge from the vagina or penis - it was originally treated using penicillin, but this has become trickier as strains of bacteria have become resistant to it - to prevent the spread, people can be treated with antibiotics and should use barrier methods of contraception e.g. condoms

Question 31

PREVENTING DISEASE: What are the 4 main ways to reduce and prevent the spread of disease?

Answer 31

- being hygienic - destroying vectors - isolating infected induviduals - vaccination

Question 32

PREVENTING DISEASE: How can being hygienic reduce or prevent the spread of disease? Give examples of ways of being hygienic

Answer 32

Using simple hygiene measures can prevent the spread of disease. For example, doing things like washing your hands thoroughly before preparing food or after you've sneezed can stop you infecting another person

Question 33

PREVENTING DISEASE: How can destroying vectors reduce or prevent the spread of disease? How can you destroy vectors?

Answer 33

By getting rid of the organisms that spread disease, you can prevent the disease from being passed on. Vectors that are insects can be killed using insecticides or by destroying their habitat so they can no longer breed

Question 34

PREVENTING DISEASE: How can isolating infected induviduals reduce or prevent the spread of disease?

Answer 34

If you isolate someone who has a communicable disease, it prevents them passing it on to anyont else

Question 35

PREVENTING DISEASE: How can vaccination reduce or prevent the spread of disease?

Answer 35

Vaccinating people and animals against communicable diseases means that they are less likely to develop the infection and pass it on to someone else.

Question 36

FIGHTING DISEASE: What parts of the body stop pathogens from getting into the body?

Answer 36

- skin - nose - breathing pipework - stomach

Question 37

PREVENTING DISEASE: How does the skin form part of the body's defence system?

Answer 37

- the skin acts as a barrier to pathogens - it also secretes antimicrobial substances which kill pathogens

Question 38

PREVENTING DISEASE: What features of you nose form part of the body's defence system?

Answer 38

hair and mucus in your nose trap particles that could contain pathogens

Question 39

PREVENTING DISEASE: How does you breathing pipework form part of the body's defence system?

Answer 39

- the trachea and bronchi secrete mucus to trap pathogens - they are also lined with cilia - hair like structures whcih waft the mucus up to the back of the throat where it can be swallowed

Question 40

PREVENTING DISEASE: How does the stomach form part of the body's defence system

Answer 40

the stomach produces hydrochloric acid which kills pathogens that make it far from the mouth

Question 41

FIGHTING DISEASE: What is the most important part of the immune system?

Answer 41

white blood cells

Question 42

FIGHTING DISEASE: What are the three ways white blood cells fight pathogens?

Answer 42

1) Consuming them (phagocytosis 2) Producing antibodies 3) Producing antitoxins

Question 43

FIGHTING DISEASE: How do white blood cells fight pathogens by consuming them?

Answer 43

they engulf foreign cells and digest them, this is called phagocytosis

Question 44

FIGHTING DISEASE: What are white blood cells that produce antibodies also know as?

Answer 44

B-lymphocytes

Question 45

FIGHTING DISEASE: Explain how white blood cells fight pathogens by producing antibodies?

Answer 45

- every invading pathogen has unique molecules (called antigens) on its surface - when some types of white blood cells come across a foreign antigen they start to produce proteins called antigbodies to lock onto the invading cells so they can be found and destroyes by other white blood cells. The antibodies produces are specific to that type of antigen - they won't ock onto any others - antibodies are then produced rapidly and carried around the body to find similar bacteria or viruses - if the person is infected by the same pathogen again the white blood cells will rapidly produce antibodies to kill it - the person is naturally immune to that pathogen and won't get ill

Question 46

FIGHTING DISEASE: How do white blood cells fight pathogens by producing antitoxins?

Answer 46

antitoxins counteract toxins produced by invading bacteria