Protozoa Flashcards
what are the main characteristics of protozoa?
complex life cycles, mostly unicellular with rare colonies and have locomotive structures
what is an oral groove?
a ciliated channel in which food is directed into the mouth
what is the main form of reproduction in protozoa?
mostly asexual
what are the stages of the life cycle of a protozoa?
begin as trophozoite, become a cyst and reproduce
what are the features of the trophozoite stage?
a motile feeding stage at which they are able to actively feed
what are the features of a cyst stage?
a dormant resistant stage in which the protozoa is able to survive in harsh conditions outside of a host
what is excystation?
when the protozoa is removed from the cyst stage
what are examples of some parasites that are motive via flagella?
giardia, trichomonas, tripanosoma and leishmania
what are the two types of amoeboid protozoa?
entamoeba histolytica and radiolarians
what are entamoeba histolytic?
protozoa that cause dysentery, abdominal pain and fever
what are radiolarians?
protozoa with a silica based skeleton and found in the sea as part of zooplankton
what are the features of amoeboid protozoa?
use pseudopods, can come in shells
what are pseudopods?
a temporary cell extension used for movement and gathering food
how do pseudopods work?
the cell membrane pushes in one direction and the cytoplasm flows into the buldge, which drags the rest of the cell behind it
what are the different types of pseudopods
lobular, blunt, branched, filamentous (long and pointed)
what allows the cytoplasm to move into the bulge formed by the cell membrane when forming a pseudopod?
the ectoplasm, which is the outer layer of the cell membrane
what kind of protozoa have cilia?
trophozoites
what are the features of ciliated protozoa?
majority of nonpathogens and have 2 nuclei
why do ciliated protozoa have 2 nuclei?
one for everyday function and one for reproduction
in what ways do ciliated protozoa reproduce?
vis binary fission or conjugation
what are apicomplexa?
parasitic protozoa
how do apicomplexa move?
by gliding or flexion
what is different about the life cycle of a apicomplexa?
they have many hosts and rarely produce cysts
what enables an apicomplexa to transfer to a new host?
they produce sporozoites
what is an example of an apicomplexa?
toxoplasma gondii
in which type of protozoa does conjugation occur?
in ciliated protozoa such as paramecium
what is conjugation? why is it needed?
this is the mixing of genetic material of two protists yet no increase in the amount of protozoa, needed to gain new genetic material to better adapt to environment
what is the process of conjugation?
come into contact via oral surface, micronuclei divide to produce 4 haploid micronuclei of which 3 degenerate and 1 divides into female and male micronuclei. the male nuclei are then exchanged between conjugants