Unicellular Protists

Question 1

Giardia

Answer 1

• pathogen
• intestinal parasite that persists in water as dormant cysts
• they have modified mitochondria
• they have flagella
• rivers, streams, lakes
• symptoms: diarrhea, abdominal pain
• generally not fatal
• sometimes known as traveler’s diarrhea
• this is why you need to use water filters, iodine treatment, or boil water to make sure it is safe for drinking
• Excavata group

Question 2

Trypanosoma

Answer 2

• sleeping sickness
• has normal mitochondria, but only has one
• has flagella
• causes disease called African sleeping sickness
• vascular and lymphatic infection that may be followed by coma and death
• it is a blood pathogen vectored by tsetse flies in tropical Africa
• spread from human to human via this fly
• Excavata group

Question 3

Dinoflagellates

Answer 3

• not pathogen
• Chromalveolata group
• have cellulose plates outside the cellulose membrane
• twin flagella
• aquatic; fresh water, salt water
• photoautotrophs, heterotrophs, mixotrophs
• blooms can cause red tides
• some are bioluminescent

Question 4

Plasmodium

Answer 4

-causes malaria
-vectored by mosquitoes
-complex life cycle: sexual and asexual stages that require two hosts for completion= human and mosquitio
-causes red blood cells to burst every few days and releases wastes
-causes fever and chills
-vaccines hard to develop because of this complex lifestyle
-

Question 5

Diatoms

Answer 5

• cell wall made of silica
• makes them taste gross to other organisms
• aquatic: fresh water, marine
• major components of plankton in lakes and oceans
• play an important role in earth’s carbon cycle because they are so abundant
• can pull in carbon from the atomosphere
• fossil diatoms make up diatomaceous earth