What are some of the basic features of Excavates? Discuss the difference among major classes of organisms found in this. For the toolbar press ALT +F10 (PC) or ALT + FN + F10 (Mac) Solution Excavates are a diverse group of unicellular Protists with Flagella.These protists are so named because many have a deep, or excavated, oral groove. Unlike other protists, excavates have atypical, greatly modified mitochondria. Many excavates are endosymbionts and live in anoxic (without oxygen) environment. These excavates do not carry out aerobic respiration; they obtain energy by the anaerobic pathway of glycolysis (presumably by fermentation). The representatives protest clades are dipplomonads and parabasalids with the key characters of two or more flagella; ventral oral (feeding) groove and Euglenoids and trypanosomes with the key characters of some with plastids; crystalline red in flagella Example: SEM of Trichomonas vaginalis, a parabasalid. Currently, excavates include dipomonads, parabasalids, euglenoids, and trypanosomes. The inclusion of these organisms inti single superfamily is somewhat controversial because their relationship to one another are uncertain. Additional studies will be needed to determine if the excavates as currently presented are monophyletic group. Diplomonads are small mostly parasitic flagellates Diplomonads are excavates that have one or two nuclei, no functional mitochondria, no Golgi complex, and up to eight flagella. Example: Giardia is a parasitic diplomonad. Interestingly, Giardia has two haploid nuclei, each of which contains a complete copy of giardia’s genome. Giardia lacks functional mitochondria, although it contains certain genes that code for proteins associated with mitochondria in other organism. Giardia also has reduced structures that somewhat resembles mitochoindria. Giardia intestinalis is a major cause of water-borne diarrhea through the world. Giardia is eliminated as a resistant cyst in the feces of many vertebrate animals. These cysts are common contaminant in untreated drinking water. Parabasilids are anaerobic endosymbionts that live in animals Parabasilids are anaerobic, flagellated excavates that often live in animals. Trichonymphs and trichomonads are examples of parabasilids. Trichonymphs, which have hundreds of flagella, live in the guts of termites and wood-eating cockroaches. The trichonymphs rely on endosymbiotic bacteria to digest cellulose in the wood. The insects, trichonymphs, and bacteria all obtain their nutrients from this source. This is excellent example of mutualism..

1. What are some of the basic features of Excavates? Discuss the difference among major classes
of organisms found in this. For the toolbar press ALT +F10 (PC) or ALT + FN + F10 (Mac)
Solution
Excavates are a diverse group of unicellular Protists with Flagella.These protists are so named
because many have a deep, or excavated, oral groove. Unlike other protists, excavates have
atypical, greatly modified mitochondria. Many excavates are endosymbionts and live in anoxic
(without oxygen) environment. These excavates do not carry out aerobic respiration; they obtain
energy by the anaerobic pathway of glycolysis (presumably by fermentation).
The representatives protest clades are dipplomonads and parabasalids with the key characters of
two or more flagella; ventral oral (feeding) groove and Euglenoids and trypanosomes with the
key characters of some with plastids; crystalline red in flagella
Example: SEM of Trichomonas vaginalis, a parabasalid.
Currently, excavates include dipomonads, parabasalids, euglenoids, and trypanosomes. The
inclusion of these organisms inti single superfamily is somewhat controversial because their
relationship to one another are uncertain. Additional studies will be needed to determine if the
excavates as currently presented are monophyletic group.
Diplomonads are small mostly parasitic flagellates
Diplomonads are excavates that have one or two nuclei, no functional mitochondria, no Golgi
complex, and up to eight flagella. Example: Giardia is a parasitic diplomonad. Interestingly,
Giardia has two haploid nuclei, each of which contains a complete copy of giardia’s genome.
Giardia lacks functional mitochondria, although it contains certain genes that code for proteins
associated with mitochondria in other organism. Giardia also has reduced structures that
somewhat resembles mitochoindria.
Giardia intestinalis is a major cause of water-borne diarrhea through the world. Giardia is
eliminated as a resistant cyst in the feces of many vertebrate animals. These cysts are common
contaminant in untreated drinking water.
Parabasilids are anaerobic endosymbionts that live in animals
Parabasilids are anaerobic, flagellated excavates that often live in animals. Trichonymphs and
trichomonads are examples of parabasilids. Trichonymphs, which have hundreds of flagella, live
in the guts of termites and wood-eating cockroaches. The trichonymphs rely on endosymbiotic
bacteria to digest cellulose in the wood. The insects, trichonymphs, and bacteria all obtain their
nutrients from this source. This is excellent example of mutualism.