Disease

Question 1

What is a pathogen?

Answer 1

Microorganism that can cause disease

Question 2

Name 4 groups of pathogen that can cause disease?

Answer 2

• bacteria
• fungi
• protoctista
• viruses

Question 3

What is bacteria?

Answer 3

Pathogen that produces toxins damaging body cells

Question 4

What is a virus?

Answer 4

Pathogen using host cells too replicate before bursting and destroying them

Question 5

What is a protoctist?

Answer 5

Pathogen that takes over cells and breaks them open

Question 6

What is a fungi?

Answer 6

Pathogen that digests living cells and destroys them

Question 7

What is direct transmission?

Answer 7

Pathogen transmission directly from one organism to the other

Question 8

What are methods of direct transmission in animals?

Answer 8

Direct contact = skin-to skin contact e.g kissing or sexual intercourse

Airborne droplets = coughing or sneezing tiny droplets of mucus or saliva onto someone

Question 9

What is indirect transmission?

Answer 9

Pathogen is passed from one organism to another using an intermediate (e.g. water or another organism)

Question 10

What are some methods of indirect transmission in animals?

Answer 10

Food and water = ingestion of contaminated food or water

Vectors = transmit pathogens from one host to another (e.g. mosquitoes)

Contaminated objects = pathogens from infected individuals can live on objects

Question 11

What factors increase risk of communicable diseases in animals?

Answer 11

Living conditions = overcrowded areas increase risk of direct transmission

Climate = e.g warmer temps allow mosquitoes to breed and transmit malaria

Social factors = e.g lack of health education and healthcare systems increase risk

Question 12

What type of disease is tuberculosis and how is it transmitted?

Answer 12

Bacteria

airborne droplets and contaminated food and drink

Question 13

Describe tuberculosis?

Answer 13

Damages the lungs and suppresses immune system

affects humans cows and pigs

Question 14

What type of disease is bacterial meningitis and how is it transmitted?

Answer 14

Bacterium

through airborne droplets

Question 15

Describe bacterial meningitis?

Answer 15

Damages membranes of the brain and can cause blood poisoning

affects young children and teenagers

Question 16

What type of disease is HIV/AIDS and how is it transmitted?

Answer 16

Virus

exchange of bodily fluids

Question 17

Describe HIV/AIDS?

Answer 17

Gradually destroys the immune system

humans and non-human primates

Question 18

What type of disease is influenza and how is it transmitted?

Answer 18

Virus

Airborne droplets and contaminated objects

Question 19

Describe influenza?

Answer 19

Kills ciliated epithelial cells in the gas exchange system

kills mammals including humans and birds

Question 20

What type of disease is athletes foot and how is it transmitted?

Answer 20

Fungus

contaminated objects

Question 21

Describe athletes foot?

Answer 21

Causes cracking and scaling of skin between the toes

affects humans

Question 22

What type of disease is ringworm and how is it transmitted?

Answer 22

Fungus

direct contact

Question 23

Describe ringworm?

Answer 23

Causes a circular red rash

affects mammals including cattle, dogs and humans

Question 24

What type of disease is malaria and how is it transmitted?

Answer 24

Protoctist

mosquito vector

Question 25

Describe malaria?

Answer 25

Damages the RBC's liver, and brain affects humans mammals and birds

Question 26

How does direct transmission occur in plants?

Answer 26

Direct contact of a healthy plant with any part of an infected plant

Question 27

What are some examples of indirect transmission in plants?

Answer 27

Wind =spores are carried by wind to uninfected plants Water = spores travel on surface of water to reach uninfected plants Animals = insects and birds can carry pathogens or spores from one plant to another Humans = pathogens and spores can be transmitted by handling plants clothing farming tools and practices

Question 28

What factors increase risk of communicable diseases in plants?

Answer 28

Crop variety = some crops more susceptible to disease than others Overcrowding = increases likelihood of direct contact Mineral nutrition = poor nutrition reduces plant resistance Climate change = increased rainfall and wind increase disease spread

Question 29

What is ring rot?

Answer 29

Bacterium

Question 30

Describe ring rot?

Answer 30

Damages leaves tubers and fruits affects potatoes tomatoes and aubergines

Question 31

What is tobacco mosaic virus?

Answer 31

Virus

Question 32

Describe tobacco mosaic virus?

Answer 32

Damages leaves flowers and fruits many species e.g tomatoes tobacco and pepper

Question 33

What is black sigatoka?

Answer 33

Fungus

Question 34

Describe black sigatoka?

Answer 34

Attacks and destroys leaves turning them black affects banana plants

Question 35

What is potato/tomato blight?

Answer 35

Protoctist

Question 36

Describe potato/tomato blight?

Answer 36

Destroys leaves tubers and fruits affects potatoes and tomatoes

Question 37

What are some examples of plant physical defences?

Answer 37

Waxy cuticles = covers leaves and stems providing physical barrier against pathogens Cell walls = surrounds plant cells forming physical barrier against pathogens Callose production = produce polysaccharide called callose that's deposited between cell wall and cell-surface membrane when under attack from pathogen

Question 38

What are some examples of plant chemical defences?

Answer 38

Insect repellents = reduce insect number feeding on plants to prevent pathogen transmission Insecticides = kill insects preventing pathogen transmission Antibacterial substances = Chemicals e.g antibiotics produced to kill bacteria or inhibit growth Toxins = chemicals that break down into cyanide (toxic) when under attack