B3: Infection And Response (triple)

Question 1

What are the 4 types of pathogens?

Answer 1

Bacteria
Viruses
Protists
Fungi

Question 2

Describe bacteria.

Answer 2

100th the size of body cells
Reproduce rapidly
Produce toxins which damage cells and tissue

Question 3

Describe viruses.

Answer 3

Not cells
100th the size of bacteria
Reproduce rapidly 
Replicate inside body cells then burst out
Damage cells

Question 4

Describe protists.

Answer 4

Single called eukaryotes
Some are parasites That live on or inside other organisms causing them damage
They are transferred to the organism by a vector which doesn’t get the disease

Question 5

Describe fungi.

Answer 5

Some are single celled
Others have bodies made up of hyphae
Hyphae grow and can penetrate human skin and plants, causing diseases
Hyphae produce spores which can spread to other organisms

Question 6

What are the 3 ways pathogens can spread?

Answer 6

Water
Air
Direct contact

Question 7

What is measles?

Answer 7

Viral disease 
Spread by droplets in a sneeze or cough 
Causes red skin rash and fever
Complications can cause pneumonia or encephalitis 
Most people are vaccinated

Question 8

What is HIV?

Answer 8

Virus
Spread by sexual contact or exchanging bodily fluids
No symptoms for several years
Flu like symptoms
Attacks immune cells
Your body can’t deal with other infections or cancer

Question 9

What is tobacco mosaic virus?

Answer 9

Effects plants
Creates mosaic pattern on leaves causing discolouration leading to less photosynthesis
Virus effects growth

Question 10

What is rose black spot?

Answer 10

Fungus
Causes purple or black spots on leaves of roses
Leaves turn yellow and drop off
Less photosynthesis preventing growth
Spreads through water or wind
Combatted by fungicides and stripping effected leaves

Question 11

What is malaria?

Answer 11

Causes by protist
Picked up by mosquitos that feed on infected animals
Causes repeating episodes of fever
Can be fatal
People can be protected by insecticides and mosquito nets

Question 12

What is salmonella?

Answer 12

Bacteria that causes food poisoning
Causes fever, stomach cramps, vomiting and diarrhoea
Caused by toxins the bacteria produces

Question 13

What is gonorrhoea?

Answer 13

Bacterial STD
Passed on by sexual contact
Causes pain whilst urinating and causes a thick yellow or green discharge
Was treated by penicillin but is now resistant
Can be treated by antibiotics or barrier methods

Question 14

What are the 4 ways in which diseases can be prevented?

Answer 14

Being hygienic
Destroying vectors
Isolating infected individuals
Vaccination

Question 15

What are the 3 ways your immune system attacks pathogens?

Answer 15

White blood cells consume them
White blood cells produce antibodies
White blood cells produce antitoxins

Question 16

What are antibodies produced by?

Answer 16

A type of white blood cell called B-lymphocytes.

Question 17

What are the 4 steps of producing monoclonal antibodies?

Answer 17

1. a mouse is injected with the antigen.
2. the lymphocyte that is producing the effective antibodies is removed from the mouse.
3. this B-lymphocyte is fused with a tumour cell to produce a hybridoma.
4. this divides quickly creating lots of hybridomas that can produce antibodies.

Question 18

What 3 physical defences do plants have?

Answer 18

waxy cuticle.
cells have cell walls made from cellulose.
plants have layers of dead cells around their stems.

Question 19

What 2 chemical defences do plants have?

Answer 19

can produce antibacterial chemicals.

can produce poisons to deter herbivors.

Question 20

What 3 mechanical defences do plants have?

Answer 20

thorns and hairs that stop animals from touching or eating plants.
some plants can droop or curl when something touches them knocking off insects.
some plants can mimic animal habits to deter animals.