Mycology, Virology, Parasitology (W4)

Question 1

Define Mycoses

Answer 1

disease caused by fungi

Question 2

What are the control methods for fungi (how to kill them)

Answer 2

• 60 deg for 5-30 mins
• bleach
• phenolic compounds

Question 3

What are the 4 classifications of fungi

Answer 3

1. Moulds
2. True Yeast
3. Yeast-like fungi
4. Dimorphic fungi

Question 4

define dimorphic fungi

Answer 4

it can be yeast or mycelial depending on environment

Question 5

What are the 2 morphological types of hyphae and what defines them

Answer 5

septate - little walls along branches
non-septate - no walls

Question 6

what are 5 harmful effects of fungi

Answer 6

• food spoilage
• unwanted growth
• animal and plant disease
• mycotoxin production
• lab contamination

Question 7

what are 6 benefits of fungi

Answer 7

• food preparation
• antibiotic production
• enzyme production
• acid production
• decomposition
• pesticides degradation

Question 8

what are the growth requirements of fungi

Answer 8

• temp between 25 and 30 degs
• acidic pH (4-6)
• Moist
• aerobic

Question 9

what are the 5 types of asexual spores for fungal reproduction
(SCCAB)

Answer 9

• Sporangiospores
• Chlamydospores
• Conidiospores
• Arthrospores
• Blastospores

Question 10

what are the 4 stages of fungal sexual spore formation

Answer 10

1. cells of + and - thallus fuse
2. nuclei fuse
3. meiosis of nucleus (back to 2 nuclei)
4. Haploid nucleus partitioned into + and - thallus

Question 11

what are the 4 classifications based on fungal sexual reproduction

Answer 11

• Zygomycota
• Basidiomycota
• Ascomycota
• Deuteromycota (no sexual stage)

Question 12

what are the 4 types of pathogenic fungi

Answer 12

1. Moulds (opportunistic)
2. Dermatophytes
3. Yeast-like fungi
4. Dimorphic fungi

Question 13

What are the 2 types of superficial fungal infections

Answer 13

Candida (mucosa)
Cutaneous (skin)

Question 14

what causes dermatophycoses

Answer 14

dermatophytes (on skin, hair, nails only)
(tinea)

Question 15

what fungal pathogen causes systemic mycoses and what are 4 types

Answer 15

Dimorphic fungal pathogens
- Histoplasmosis
- Blastomycosis
- Coccidioidomycosis
- paracoccidioidomycosis

Question 16

What are mycotoxins, can they ever be useful

Answer 16

toxins produced by fungi, yes some of them

Question 17

how many bacteriophages per ml of seawater are there

Answer 17

10 - 50 million

Question 18

what is the size of a virus

Answer 18

10 - 300/400 um

Question 19

what are the Baltimore scheme classifications of viruses and what is it based off

Answer 19

• based off nucleic acid

Class 1 - Double stranded DNA
Class 2 - Single stranded DNA

Class 3 - double stranded segmented RNA
Class 4 - single stranded RNA negative sense
Class 5 - single stranded RNA positive sense

Class 6 - Single stranded RNA positive sense with double stranded DNA intermediate before replication

Class 7 - double stranded DNA, part single stranded DNA with single stranded RNA intermediate

Question 20

what are the 3 morphological types of viruses

Answer 20

1. Helical
2. Icosahedral
3. Complex/undefined

Question 21

what are cytopathic effects and what are they caused by

Answer 21

structural changes of a host cell caused by viral infection

Question 22

what are the 6 stages of viral replication

Answer 22

1. Attachment
2. Penetration
3. replication of viral genome
4. production of late viral proteins
5. assembly of progeny virions
6. release of virions from cell

Question 23

what 2 ways can viruses cause disease

Answer 23

1. replicate in host cell, leading to direct damage
2. host cells kill virus infected cells

Question 24

what are the types (classifications) of viral infection

Answer 24

• mild
• latent (in body without producing more viruses)
• severe
• oncogenic (develop cancer)
• Teratogenic (affects fetus)

Question 25

what is the transmission mode unique to viruses

Answer 25

Arthropod-borne (transmitted by arthropods (insects))

Question 26

what are the two types of helminths (worms)

Answer 26

Nematodes (round)
platyhelminths (flat)

Question 27

how big is the liver fluke, where does it live and what does it feed on

Answer 27

its is 25mm long and lives in the bile duct and feeds on the liver

Question 28

what causes Fascioliasis and what is this

Answer 28

liver flukes, it is an infectious disease that causes fever, tiredness, loss of appetite and pain around liver

Question 29

what is the common name for a Cestodia

Answer 29

tapeworm

Question 30

what are the symptoms of tape worm

Answer 30

• abdominal pain
• anemia
• nervous disorders
• gut irritation

Question 31

what can happen if reverse peristalsis occurs when you have a tapeworm

Answer 31

mature worms lay eggs in the stomach, can invade nervous tissue - this is fatal

Question 32

what are cysticerci

Answer 32

Tape worm larvae

Question 33

how are nematodes diagnosed

Answer 33

eggs in faeces

Question 34

what type of infection is malaria and how is it transmitted

Answer 34

protozoan infection, transmitted by mosquito vector

Question 35

state the pathway starting from an insect bite causing malaria, ending at RBC lysis

Answer 35

insect bites human - sporozoite enters and moves to liver - reproduces over several days - release metrozoites into blood - infect red blood cells - cause RBCs to burst and release more metrozoites

Question 36

why are nematode infections so common

Answer 36

transmission is fecal oral by water

Question 37

what are the symptoms of malaria

Answer 37

• fever
• chills
• nausea
• headache

Question 38

what are 3 common types of nematodes

Answer 38

• Ascaris Lumbricoides
• Trichuris Trichiura
• enterobius vermicularis