Infection and response

Question 1

What are the different types of pathogens?

Answer 1

Bacteria, viruses, protists and fungi

Question 2

What are bacteria?

Answer 2

Very small cells, can reproduce rapidly in body and produce toxins that can damage cells

Question 3

What are viruses?

Answer 3

Not cells, reproduce rapidly, replicate themselves using cells information and burst cells making you feel ill.

Question 4

What are protists?

Answer 4

Single celled eukaryotes and are often parasites that live on or inside other organisns

Question 5

What are fungi?

Answer 5

Either single-celled, or have a body made up of hyphae which can grow, penetrate plants and produce spores

Question 6

How can pathogens spread?

Answer 6

Water, air or direct contact

Question 7

What are the symptoms of measles and how is it spread?

Answer 7

Red skin rash and droplet infection

Question 8

What are the symptoms of HIV and how is it spread?

Answer 8

Flu-like symptoms, then no symptoms for a few years and by sexual contact or exchange of bodily fluids

Question 9

How does HIV damage the body?

Answer 9

The virus attacks the body’s immune cells so it can’t defend itself from other infections

Question 10

What are the symptoms and affects of TMV?

Answer 10

Causes a mosaic pattern on the leaves so plants can’t carry out photosynthesis so it affects the plant’s growth

Question 11

What are the symptoms and affects of rose black spot?

Answer 11

Purple/black spots, leaves turn yellow then drop off and less photosynthesis so plant’s growth is stunted

Question 12

What are the causes and symptoms of malaria?

Answer 12

Infection from mosquito inserting protist into blood cells and causes repeating episodes of fever

Question 13

How do you get salmonella food poisoning and what does it cause?

Answer 13

Eating contaminated food and it causes fever, stomach cramps, vomiting and diarrhoea

Question 14

How is gonorrhoea spread and what are the symptoms?

Answer 14

Sexual contact and causing pain when urinating and a yellow or green discharge

Question 15

How can the spread of disease be prevented?

Answer 15

Being hygienic, destroying vectors, isolating infected individuals and vaccination

Question 16

What features does the human body have to prevent pathogens from entering?

Answer 16

Skin as a barrier with antimicrobial substances, hair with mucus in nose to trap particles, trachea with mucus as well, cilia in throat waft back up substances and hydrochloric acid in the stomach

Question 17

What is phagocytosis?

Answer 17

Where white blood cells engulf foreign cells and digest them

Question 18

How do white blood cells produce antibodies to stop pathogens?

Answer 18

The antibodies produced are specific to a type of antigen, once they lock onto the shape, antibodies are then produced rapidly to fight off the infection. If the pathogen comes back, then the body remembers

Question 19

How do antitoxins stop pathogens?

Answer 19

These counteract toxins produced by invading bacteria

Question 20

What is a vaccine?

Answer 20

Injecting someone with a small amount of dead or inactive bacteria so that your body can produce antibodies to attack them and remember this if the pathogen ever comes back

Question 21

What are the pros of vaccination?

Answer 21

They can control communicable problems and prevent epidemics

Question 22

What are the cons of vaccination?

Answer 22

They don’t always work and you can sometimes have a bad reaction to them

Question 23

How do painkillers work?

Answer 23

They relieve pain by reducing the symptoms, but not by taking care of the actual disease

Question 24

How do antibiotics work?

Answer 24

They kill or prevent the growth of the bacteria causing the problem, but do not destroy viruses

Question 25

How can bacteria become resistant to antibiotics?

Answer 25

They can mutate - some of the mutations may be resistant and when the bacteria is treated, only the non-resistant strains will be killed

Question 26

Where is aspirin from?

Answer 26

It was developed from a chemical found in the willow

Question 27

Where was penicillin from?

Answer 27

A type of mould

Question 28

What are the three main stages in drug testing?

Answer 28

Preclinical testing on human cells and tissues, preclinical testing on live animals and testing on human volunteers (healthy ones, then ones with the disease, then placebos)

Question 29

What are monoclonal antibodies?

Answer 29

Identical antibodies

Question 30

How are monoclonal antibodies produced?

Answer 30

By fusing a B-lymphocyte (type of white blood cell) to a tumour cell to create a hybridoma which can be cloned to get lots of identical cells which all produce the same type of antibodies

Question 31

How do pregnancy tests work if you’re pregnant?

Answer 31

The part of the stick you wee on has some antibodies to the pregnancy hormone with blue beads attached to them and the test strip has some of these as well. If you’re pregnant then the hormone binds to the antibodies on the blue beads, which then moves up the strip and the same thing happens on the strip so the strip turns blue

Question 32

How do pregnancy tests work if you’re not pregnant?

Answer 32

The urine stills moves up the stick, carrying the blue beads but there’s nothing to stick it onto the test strip so it doesn’t go blue

Question 33

How can monoclonal antibodies be used to treat cancer?

Answer 33

You can make monoclonal antibodies that bind to the tumour markers (antigens) then attach an anti-cancer drug to this so the drug kills the cancer cells but not the healthy ones

Question 34

What are the problems with monoclonal antibodies?

Answer 34

They have side effects such as fever, vomiting and low pressure which means that they are not as widely used as was originally thought

Question 35

What are the common signs of disease in plants?

Answer 35

Stunted growth, abnormal growths, spots on the leaves, malformed stems or leaves, patches of decay and discolouration

Question 36

What physical defenses do plants have?

Answer 36

Waxy cuticle as barrier, cell walls as physical barrier and layers of dead cells around stems as another barrier

Question 37

What chemical defences do plants have?

Answer 37

Some can produce antibacterial chemicals and others can produce poisons which can deter herbivores

Question 38

What mechanical defences do plants have?

Answer 38

Thorns/hairs, some droop or curl when touched and some mimic other organisms to trick organisms into not eating them