Parasites: PROTOZOA and FLAGELLATES

Question 1

Cyst

Answer 1

protective membrane, protective stage, dormant

Question 2

Trophozoite

Answer 2

motile, active, feeding, reproductive stage

Question 3

Entamoeba coli (cyst stage)

Answer 3

non-pathogenic parasites;
multiple nuclei develop as the cyst matures;
sometimes chromatoid bodies are visible (aggregations of ribosomes that form masses)

Question 4

Entamoeba coli (trophozoite stage)

Answer 4

one nucleus with a large karyosome (a dense bundle of chromatin);
digested RBCs within the body

Question 5

Entamoeba histolytica (cyst stage)

Answer 5

pathogenic parasite: leads to dysentery and liver abscesses;
key features: multiple nuclei (usually four);
large chromatoid body (cigar-shaped)

Question 6

Entamoeba histolytica (trophozoite stage)

Answer 6

cytoplasm may have granulated look due to digested RBCs/yeast;
karyosome is central inside one nucleus;
can be malformed (not exactly circular)

Question 7

Giardia lamblia (cyst stage)

Answer 7

oval shape;
nuclei (2-4) on one side of parasite
axostyle: cutting the body in half

Question 8

Giardia lamblia (trophozoite)

Answer 8

2 nuclei w/ central karyosome;
ventral disk: used for attachment to intestinal lining;
split body;
have flagella