Asexual reproduction by multiple fission, found in some protozoa
What do protozoans eat?
Little tiny algae and bacteria particles
How do protozoans move?
Cilia, flagella and pseudopods
How is protozoan conjugation different from bacterial conjugation?
Conjugation in bacteria is less complex because the DNA is only transferred to the one other cell. In protists its more complex because the DNA from both cells are being put together to form a whole new cell.
What is a protozoan cyst and why are they important to parasitic protozoans?
Its a defense mechanism that help them survive harsh conditions. Being a cyst enables parasitic species to survive outside the host and to transfer to another host.
What are three pathogenic flagellates and the diseases they cause?
Trichomonas vaginalis: Trichinosis, Giardia lamlea: Giardia and Dientamoeba fragilis
What is a Hemoflagellate? What diseases do they cause?
a blood parasite. Causes African sleeping sickness
What disease does Giardia cause? How is it transmitted?
Giardiasis is found in the intestines and is ingested through contaminated water
What is the common characteristic of Apicomplexans?
obligate intercellular parasite
What diseases are caused by Plasmodium (What are the intermediate and definitive hosts)?
Malaria; intermediate host is humans, definitive host is the anopheles mosquito
What diseases are caused by Toxoplasma (What are the intermediate and definitive hosts)?
Toxoplasma; definitive host is felines with all other hosts defined as intermediate
What diseases are caused by Crytosporidium (What are the intermediate and definitive hosts)?
Cryptosporidosis; definitive host is humans, intermediate host is cows, rodents, dogs, cats
What is an intermediate host?
an organism that supports the immature or nonreproductive forms of a parasite
What is a definitive host?
an organizm that supports the adult or sexually reproductive form of a parasite.
In what two phyla are most parasitic helminths?
Flatworms (platyhelminthes) and roundworms (nematoda)
What are the characteristics of parasitic helminths that differ from free living varieties?
May lack digestive system, reduced nervous system, reduced or lacking mode of locomotion, complex reproductive/life cycles
What type of tissue does a blood fluke infect?
What kind of worm is made of a scolex and proglottids? How does it obtain nutrients?
Tapeworms (cestodes) Absorbs fluids through cuticle (skin)
Describe the life cycle of the beef tapeworm.
ingested by cattle, larvae hatch and burrow into muscle and encyst. Meat with cysts is eated, infection occurs. Spread by infected fecal matter
How do nematodes (roundworms) differ from platyhelminths (flatworms) (digestive and reproductive systems)?
Roundworms have digestive systems, flatworms absorb fluids through the skin.
Life cycle of Enterobius (pinworm)
spends whole cycle in humans, adults in large intestine, females migrate to anus to deposit eggs at night, eggs are digested by host or another human through contaminated articles like clothing.
Life cycle of Ascaris
Found in humans, pigs and horses. Feeds on semi digested food. Eggs excreted by host and may survive in soil for long periods until ingested again. Eggs hatch in small intestines, mature in lungs and migrate to instestines.
Life cycle of Necator (hookworm)
Small intestines in humans, eggs excreted in feces, larvae hatch in soil and feed on bacteria. Larvae enter host through skin of feet then enter lymph and blood vessels and are carried to lungs. Coughed up and swallowed returningn to small intestines
Life cycle of Trichinella
Encysted in undercooked meat. Larvae mature into adults in small intestine then sexually reproduce, eggs develop in female and live larvae are released. They enter lymph and blood vessels and migrate throughout body and encyst in muscle and remain until ingested by a new host.