module 4 - 12.2 animal and plant diseases

Question 1

what is ring rot?

Answer 1

• bacterial disease of potatoes, tomatoes & aubergines
• caused by gram positive bacterium
• damages leaves, tubers and fruit
• once ring rot infects a field it cannot be used to grow potatoes again for 2+ years

Question 2

what is tobacco mosaic virus?

Answer 2

• virus that infects tobacco plants
• damages leaves, flowers & fruit, stunts growth yields - can lead to almost total crop loss
• no cure

Question 3

what is potato blight?

Answer 3

• caused by fungus-like protoctista
• hyphae penetrate host cells, destroying leaves, tubers and fruit
• no cure

Question 4

what is black sigatoka?

Answer 4

• banana disease caused by fungus
• attacks & destroys leaves
• hyphae penetrate & digest cells, turns leaves black
• no cure

Question 5

what are animal diseases?

Answer 5

• diseases that can affect animals
• have an effect on health and wellbing & natural economies

Question 6

what is toburculosis?

Answer 6

• communicable disease
• destroys lung tissue and suppresses immune system (body less able to fight other diseases)
• curable (anitbiotics)

Question 7

what is bacterial meningitis?

Answer 7

• bacterial infection
• meningitis of the brain (protective membranes on surface of the brain) which spreads to rest of the body
• blotchy red/purple rash
• curable (antibiotics)

Question 8

what is HIV/AIDS?

Answer 8

• AIDS caused by HIV - targets T helper cells in the immune system
• gradually destroys immune system so affected people are open to other infections
• can affect humans and non-humans
• passed through bodily fluids
• no vaccine, no cure

Question 9

what type of virus is HIV?

Answer 9

• retrovirus with RNA as its genetic material
• contains enzyme transcriptase - transcribes RNA to single strand of DNA to produce DNA in host cell

Question 10

what is influenza (flu)?

Answer 10

• viral infection of ciliated epithelial cells in gas exchange system
• kills them, leaving airways open to secondary infection
• can be fatal - no cure
• mutate rapidly

Question 11

what are the strains of influenza?

Answer 11

• 3 main strains (A, B, & C)
• A strain (most virulent) & are classified further by proteins on their surfaces

Question 12

what is malaria?

Answer 12

• caused by protoctista
• spread by bites of infected mosquitoes (vectors)
• complex lifestyle - 2 hosts (mosquitoes and people)
• female needs to take 2 blood meals for protein before she lays eggs

Question 13

what can malaria do in the body?

Answer 13

• invade red blood cells, liver, brain
• makes people more vulnerable to other infections

Question 14

what is ring worm?

Answer 14

• fungal disease affecting mammals
• different fungi affect different species
• causes grey-white crusty infectious, circular areas of skin (may be itchy)
• antifungal creams are an effective cure

Question 15

what is athlete’s foot?

Answer 15

• human fungal disease, form of human ring worm that grow and digests in warm, moist skin between toes
• causes cracking and scaling
• antifungal creams are an effective cure

Question 16

what are monoclonal antibodies?

Answer 16

antibodies made cells of the immune system that recognise one specific antigen

Question 17

how do you identify pathogens?

Answer 17

• traditionally pathogens were cultures in the lab and identified with microscope
• monoclonal antibodies can be used now to identify pathogens
• DNA sequencing technology means pathogens can be identifies precisely, down to a single mutation