protists: the unicellular eukaryotes Flashcards
most organisms are grouped together because they are similar or closely related to each other. how does the grouping of protists by taxonomists differ from this?
protists can be divided into distinct groups (red, green, and brown algae) but some taxonomists place them in the plant kingdom, others in protist, and other consider red/green algae as plants but brown algae as protists
what is the function of a pseudopod?
“false feet”- a temporary cytoplasmic extension that amoebas use for feeding and movement
what are the similarities between cilia and flagella?
are hairlike projections that function in locomotion
some are freeliving and some are parasites
cilia length
short
flagella length
long
cilia function
in cell movement and particle manipulation when coordinated with other cilia
flagella function
extending from the cell membrane and propelling the cell with a whiplike motion
where is a well known cilia found?
in the genus Paramecium - paramecia
what protects the flagella?
hard protective covering
how long is the cilia?
100 or more μm
do cilia or flagella live in mutualistic relationships?
flagella
does cilia or flagella cover the cell?
cilia
what are plasmodial and cellular slime moulds? are they related?
fungus-like protists
no strong evidence that they are related
plasmodial slime moulds
what do they appear to the unaided eye as?
tiny sluglike organisms that creep over damp, decaying plant material in forests and fields (called a plasmodium)
plasmodial slime moulds
do they have nuclei?
yes- many
plasmodial slime moulds
how do they feed?
by engulfing small particles of food into its cytoplasm
plasmodial slime moulds
how is some of the cytoplasm concentrated?
to form a skeleton-like structure through which the liquid cytoplasm forms
cellular slime moulds
how do they exist?
as individual amoebid cells with one nucleus
cellular slime moulds
how do they feed?
by ingesting tiny bacteria or yeast cells
cellular slime moulds
what happens when food is scarce?
releases chemicals that causes them to gather, forming a psuedoplasmodial
give two examples of protists that are parasites and the problems they cause their host
Entamoeba hystolitica- feeds on lining of small intestine in humans; causes amoebic dysentery (severe diarrhea)
Balantidium coli- lives in large intestine; causes diarrhea
what is amoebic dysentery?
Entamoeba hystolitica feeds on the lining of the small intestine in humans and causes amoebic dysentery
how can Entamoeba hystolitica spread?
by drinking contaminated water or eating contaminated produce
