Survey of Eukaryotes 2

2 types of protozoa cell shapes

ciliates and amoeba

Protozoa cell shape: amoeba

constantly change shape

Protozoa size range

3-300 micrometers

Number of known protozoa species

around 65,000

Protozoa nutrition

feed on organic material such as algae and bacteria

Protozoa feeding structures

oral groove in some species; pseudopodia for phagocytosis in amoebas

Protozoa alternative feeding

absorb nutrients directly through the cell membrane

Primary limiting factor for protozoa survival

moisture availability

Structures for protozoan motility

flagella, cilia, and pseudopodia

Trophozoite lifecycle stage

active living and feeding stage; requires food and moisture 

Cyst lifecycle stage

resistant, dormant stage that helps survive unfavorable conditions and aids in disease transmission

Protozoa reproduction

can reproduce both asexually and sexually

Protozoa taxonomy criteria

method of motility, mode of reproduction, and stages in lifecycle 

Four groups of protozoa

mastigophora, sarcodina, ciliophora, apicomplexa

Protozoa taxonomy: mastigophora

move using flagella or flagella + pseudopodia

single nucleus

form cysts

Protozoa taxonomy: Sarcondina

only asexual reproduction

Protozoa taxonomy: Ciliophora

motility via cilia

mainly not pathogenic, harmlessP

Protozoa taxonomy: Apicomplexa

motility is absent except in male gametes

all are parasitic