What are three ways protazoans are classified?
- - Class
- - On the basis of their method of locomotion, with some using flagella, and others using the classical pseudopodial movement.
- - by their mode of reproduction
Structure of protazoans?
- Size varies.
- They contain membrane-bound nuclei and cytoplasm.
- The cytoplasm is divided into:
- Inner form – endoplasm
- Outer form – ectoplasm
What is true about most infectious protazoans?
- Are facultative anaerobes
- Are heterotrophs
- Have a highly developed reproductive system
- Some form cysts as a way of protecting themselves.
- The cysts can also be a mechanism of transmission from host to host.
What are helminths and what are the two types?
Worms, parasitic and free living
What is true of parasitic helminths specifically?
- They are bilaterally symmetrical and of various lengths.
- The body is covered by a tough cellular cuticle.
- Some have suckers, hooks, or plates which are used for attachment.
- 3 types: Nematodes, cestodes, trematodes
What is true of all helminths?
- Differentiated organs
- Primitive nervous systems
- Primitive excretory systems
- Highly developed reproductive systems
- They do not have a circulatory system.
Characteristcs of intestinal nematodes
- Fusiform body shape
- Tough outer cuticle
- Male and female forms
- Thousands of offspring are produced
- Eggs must incubate outside the host to become infective
- There is a larval form.
What are some different types of intestinal nematodes?
Pinworms (Enterobius vermicularis)- Whipworms (Trichuris trichiura)- Large roundworms (Ascaris lumbricoides and Strongyloides stercoralis)
What are cestodes?
- Have a flat, ribbon-shaped body
- The head contains suckers and frequently has hooks for attachment.
- They generate proglottids
- reproductive segments with male and female gonads.
- Have no digestive tract
- nutrients are absorbed across their cuticle.
- Some use one host and others two for their life cycle.
- The largest of the intestinal parasites
- Lack a vascular and respiratory system
- Lack a gut or body cavity
- Nutrients are absorbed across the cuticle.
- The adult body has three sections:
- Head,the scolex which may have a rostellum
- Regenerative neck
- Segmented body
What are two forms of fungal states?
- - Molds (multicellular)
- - Yeasts (Unicellular)
What are saphrobes?
Heterotrophs that decompose dead organic matter
What is budding?
A little bud starts growing off of parent cell, at first, bud is a lot smaller than parent cell, then it gets bigger and bigger and eventually breaks off but will probably still be smaller than the parent cell and might even still be connected by a canal. Eventually it will become as big as the parent cell. The simplest form of growth that can occur with fungi. Small buds in their beginning stages are called blastoconidia and this budding usually occurs in yeasts
Asexual reproductive elements of fungi. Involves mitotic division and budding
- What fungi use for sexual reproduction.
- Three types: ascospores, zygospores basidiospores.
- In sexual reproduction, haploid nuclei of the donor and recipient cells fuse to form a diploid nucleus, which may then divide by meiosis.
- It is during this fusion that genetic recombination occurs in fungi.
Dimorphic fungi have both mold and yeast life-cycle stages
Individual fungal filaments, tube-like extensions of the cytoplasm that may have thick parallel cell walls. Occurs in molds
Hyphae in which walls separate adjacent cells (septums)
What kind of metabolism do fungi utilize and are they aerobic or anaerobic?
Fungi utilize heterotrphic metabolism, requiring carbon for growth and obtaining nutrients from decaying organic matter. There is considerable metabolic diversity in these organisms. Most fungi are obligately aerobic, and although there are some facultative anaerobic forms, there are no obligately anaerobic fungi.