Parasites Flashcards
1
Q
What is a parasite?
A
Organisms that live in or on a host and obtain nutrition/ nourishment at the expense of the host, so they do harm
Tapeworm, ticks, leeches, fleas, headlice
2
Q
Endo and ectoparasites
A
Endoparasites lives inside a host organism and ecto live on host
- Ectoparasites live on the outside of a host organism
3
Q
Comparisons with mammal nutrition
A
- SAME = Obtains food and nutrients from other organisms (heterotrophic)
- DIFFERENT = parasites have no digestive system and requires food digested by host but mammals digest food themselves
4
Q
Tapeworm location
A
- Small intestine wall
- Lacks a digestive system
- Small intestine has products of digestion that can diffuse across
5
Q
How is tapeworm (Taenia solium) transmitted?
A
- Eggs/ embryos passed out in faeces
- Infective stage in pig (secondary host) in larvae form
- Humans eat raw and infected pork
6
Q
Features of tapeworm (gut parasites)
A
- Suckers and hooks = attach scolex to the gut wall
- Embedded deeply into wall so cannot be removed by passage of gut contents
- Large SA:V
- Thin and flattened segments proglottids
- Short diffusion pathway of digested products in gut
- Hermaphrodite (male + female reproductive organs)
- Produces large no of eggs
7
Q
Why do tapeworms not need mouth or digestive system?
A
- Digested products/ nutrients of host absorbed through the body surface which has a large SA:V so no mouth
- Food is pre-digested by the host so no need to digest own food
8
Q
Respiration
A
- Relies on anaerobic respiration for metabolism
- Oxygen levels in intestine too low for aerobic respiration
- Low metabolic rate and does not require aerobic respiration
9
Q
Tapeworm body wall
A
- Thick cuticle to protect from effects of acid and enzymes
- Lime cell secrete alkaline solution to neutralise acid
- Mucus from gland cells to protect worm from digestive enzymes
- Microtriches (microvilli) increase SA for absorption of digested food
