5.2 Pathogens and disease

Question 1

What are pathogens

Answer 1

microorgainsms that cause disease

Question 2

Give examples of pathogens

Answer 2

bacteria, viruses, protists, fungi

Question 3

What are communicable diseases caused by

Answer 3

directly by a pathogen or by a toxin made by a pathogen

Question 4

Examples of communicable diseases

Answer 4

cold, tonsillitis, tetanus, influenza, HIV/AIDS

Question 5

What are the differences between bacteria and viruses?

Answer 5

• Bacteria are single-celled organisms and smaller than animal and plant cells, digest food or medicines - insulin, treat sewage.
• Viruses are smaller than bacteria, regular shapes, cause disease in every type of living organism

Question 6

How do bacteria cause disease?

Answer 6

• Bacteria divide rapidly by splitting in two (binary fission)
• may produce toxins, making you feel ill,
• sometimes they directly damage cells

Question 7

How are pathogens spread by air and what can they cause

Answer 7

• carried and spread from one organism to another in the air
• When you are ill, you expel tiny droplets full of pathogens from breathing system when you cough, sneeze, talk
• others breathe in droplets along with pathogens, picking up infection

Question 8

How can direct contact cause pathogens to spread

Answer 8

• disease spread by direct contact of infected organism with healthy one
• in humans: Sexually transmitted infections, by direct contact of skin
• Pathogens (eg HIV/AIDS or hepatitis) enter through direct sexual contact, cuts, scratches and needle punctures
• animals act as vectors of both animal and plant diseases by carrying pathogen between infected and uninfected individuals

Question 9

How can water spread pathogens

Answer 9

• for plants: fungal spores carried in splashes of water
• for humans: eating raw, undercooked or contaminated food, drinking water containing sewage
• can spread diarrheal diseases, cholera, salmonella
• pathogen enters body through the digestive system

Question 10

what is a toxin

Answer 10

harmful chemcial produced by a microorganism

Question 11

What are the most common pathogens in plants?

Answer 11

Viruses and fungi

Question 12

What are the different uses of bacteria?

Answer 12

• used to make food such as yoghurt and cheese
• treat sewage
• make medicines
• important in the environment as decomposers
• good gut bacteria important for health and bacteria

Question 13

How do viruses spread disease?

Answer 13

• Viruses take over cells
• they live and reproduce inside cells, damaging and destroying them

Question 14

What are common disease symptoms and what are they caused by?

Answer 14

• high temperature, headaches, rashes
• they are caused by the way the body responds to cell damage and toxins produced by pathogens

Question 15

What are example of diseases caused by droplet infection?

Answer 15

flu, tuberculosis, cold

Question 16

Examples of sexually transmitted infections

Answer 16

syphilis, chlamydia

Question 17

Describe why viruses destroy cells

Answer 17

Viruses infect cells; they replicate inside and burst open the cells when they escape

Question 18

Why does a sore throat caused by bacteria lead to high body temp

Answer 18

Body is responding to cell damage and toxins produced by bacteria (body raises temp to slow down growth of bacteria)

Question 19

Why does you throat feel sore during a bacterial infection

Answer 19

Bacteria are damaging cells lining his throat / producing toxins that affect the cells