Quiz 2 revision

Question 1

Describe the diagnosis and control/ prevention of Amoebiasis

Answer 1

Stools are collected as samples for faecal microscopy which can include wet mount & staining, antigen test, serology

Looking for cysts in the faeces

Prevention would be to be use good hygiene and avoid handling food if infected

Question 2

Describe the pathogenesis of Amoebiasis

Answer 2

Mature cysts are ingested

There is Excystation into trophozoites

This will then multiply and form cysts and go straight through the intestinal tract and enable the faeces to infect another source

Question 3

Describe the pathogenesis

Answer 3

There can be other animals that become infected after ingesting faeces that is also infected

Question 4

Describe the diagnosis and control/prevention of Toxoplasmosis

Answer 4

Serology, although tissue cysts may be observed in stained biopsy specimens

PCR can also be used to detect T. gondii DNA in amniotic fluid

Question 5

Describe the pathogenesis

Toxoplasmosis

Answer 5

In a human host, the parasite from tissue cysts, most common in muscle, myocardium, brain and eyes, and these cysts may remain throughout the life of the host

(The trophozoites are released when the cysts rupture and they will develop in the cells)

Unsporulated oocysts are shed in an faeces

Oocysts take 1-5 days to sporulate in the environment and become infective. Intermediate hosts in nature become infected after ingesting soil, water or plant material contaminated with oocyst

The oocysts transform into tachyzoites after ingestion. They localise in muscle tissue

Other animals can then be infected after ingesting infected tissues containing cysts

Question 6

Describe the lifecycle and pathogenesis of Giardia

Answer 6

There is contamination of water or food with infective cysts. Then ingested into GIT

Once in the Gastrointestinal Tract the Cyst will then form into a trophozoites and then that’s what will replicate via binary fission

They will then form cysts that will infect the faeces

Question 7

What is the fungi body structure?

Answer 7

• Most common body structures are multicellular filaments and single cells

The cell walls are composed of Chitin, a polysaccharide)

In multicellular fungi, the hyphae form an interwoven mass called mycelium that infiltrates the fungi’s food source

Some fungi have fruiting bodies

Question 8

Describe the Chytrid families

Answer 8

• They are decomposers and parasites
• They can be both single celled and multicellular
• They are grouped together as their spores are flagellated

Question 9

Describe the zygomyctes

Answer 9

• Responsible for causing food to rot
• Can act as decomposers or parasite or as commensal symbionts
• During reproduction they reproduce a sturdy structure
  called zygospoangia

These are resistant to freezing and drying and are metabolically inactive

Question 10

Describe glomeromycetes

Answer 10

• they supply minerals and other nutrients to the plant forming mutualistic partnership

Question 11

Describe Ascomycetes

Answer 11

• Have a common feature which is to produce spores in a saclike sci
• They can be unicellular yeast, but many are elaborate cup and fungi and morels
• They can have repro cycles with both asexual and sexual components

Question 12

Describe Basidiomycetes

Answer 12

• Importnat decomposers of wood and other plant material

- Have a long lived heterokayrotic state in which each cell has two nuclei

Question 13

What is the importance of fungal growth in antimicrobial products?

Answer 13

Fungi secrete Penicillin which is an antibiotic

Question 14

What is the definition of parasitism?

Answer 14

An organism that lives on or in a host organism and get its food from or at the expense of its host

Question 15

Describe the general features and classification of Protozoa

Answer 15

Most are motile which is achieved by cilia, flagella and pseudopodia

Many have a. feeding/ reproducing form = trophozoite

Some form cysts = a hardy resting form with a capsule that can survive adverse conditions

• EXCAVATA
• RHIZARIA
• AMOEBOZOA
• ALVEOLATA

Question 16

What are the general features and classifications of Helminths?

Answer 16

They are multicellular invertebrates with elongated flats or round bodies

Some are motile and they have oragan system. The external surface is covered by a cuticle

They have hooks, suckers, teeth and plates

Question 17

What are the classifications of Helminths?

Answer 17

2 Classification

• Platyhelminthes: Flatworms
  These include tapeworms and flukes
• Nemahelminths: Roundworms

Question 18

How do you diagnose, control and prevent helminth diseases?

Answer 18

can be diagnosed by analysing stool samples for larvae and prevented by proper use of hygiene

Question 19

Describe the asexual and sexual reproduction of fungi

Answer 19

Mycelium produces spore-produces structures, usually hyphae, and they release spores which then germinate and then form mycelium

Sexual reproduction

Question 20

Describe the asexual and sexual reproduction of fungi

Answer 20

Mycelium produces spore-produces structures, usually hyphae, and they release spores which then germinate and then form mycelium

Sexual reproduction

Two mycelium fuse their cytoplasm and enter the heterokaryotic stage where the is a fusion of nuclei

A zygotę forms and then undergoes meiosis, releases spores and undergoes germination to form mycelium.

Provides variation

Question 21

Lifecycle and pathogenesis of Ascaris

Answer 21

Humans eats embryonate eggs and the hatched larvae enter circulation and migrate to lungs

Larvae are coughed up and swallowed and maturation proceeds in the small intestine

Question 22

Lifecycle and pathogenesis of Taenia

Answer 22

Humans are infected by eating cysticerci in poorly cooked tissues. Cysts except, develop to worm and attach with hooks and suckers to Sil wall. Worms produce proglottid segments

Mature proglottids contains eggs which are shed in human faeces