Exam 25: The Origin and Diversification of Eukaryotes

Which two genera have members that can evade the human immune system by frequently changing their cellular membrane surface proteins? 1)Plasmodium 2)Trichomonas 3)Paramecium 4)Trypanosoma

A biologist discovers an alga that is marine,multicellular,and can absorb both green and blue light.This alga probably belongs to which group?

You are given four test tubes,each containing an unknown protist.Your task is to read the following description and match these four protists to the correct test tube. When red and blue light are shone on the tubes,oxygen bubbles accumulate on the inside of test tubes 1 and 2.Chemical analysis of test tube 1 indicates the presence of a chemical that is toxic to fish and humans.Chemical analysis of test tube 2 indicates the presence of substantial amounts of silica.Microscopic analysis of organisms in test tube 3 reveals the presence of an apicoplast in each.Microscopic analysis of the contents in test tube 4 reveals thousands of cilia on the surface of the organism.Please use the following information to answer the questions below. -Test tube 2 contains

The evolution of complex multicellularity in eukaryotes

Which of the following statements about dinoflagellates is correct?

Green algae differ from land plants in that some green algae

Given its mode of reproduction and internal structures,which of the following should be expected to occur in Giardia at some stage of its life cycle? 1)separation (segregation)of daughter chromosomes 2)crossing over 3)meiosis

Protists are I.complex at the cellular level,even though they're simple compared with other eukaryotes. II.typically water-living. III.mostly unicellular. IV.exclusively heterotrophic.

The primary treatment for giardiasis (infection with Giardia),trichomoniasis (infection with Trichomonas vaginalis),and amoebic dysentery (infection with Entamoeba histolytica)is a drug marketed as Flagyl (generic name is metronidazole).The drug also kills anaerobic gut bacteria.Consequently,which of these are cues that Flagyl's mode of action has nothing to do with attacking or disabling flagella,as the drug's name might imply? 1)Flagyl would also harm the flagellated lining of the human intestine. 2)Entamoeba possesses pseudopods,not flagella,yet it is killed by Flagyl. 3)Not all anaerobic gut bacteria possess flagella,yet flagyl kills these bacteria.

Which of the following pairs of protists and their characteristics are mismatched?

You discover a new species of aerobic,mixotrophic protist that can perform photosynthesis in water up to 250 m deep.It can also crawl about and engulf small particles.Which two characteristics does your protist have to have in order to successfully complete these tasks? 1)hydrogenosome 2)apicoplast 3)pseudopods 4)chloroplast from red alga 5)chloroplast from green alga

The last common ancestor of fungi and animals was most likely a

All protists are

Why is the filamentous morphology of the slime molds considered a case of convergent evolution with fungi?

Theoretically,P.bursaria can obtain zoochlorella either vertically (via the asexual reproduction of its mother cell)or horizontally (by ingesting free-living Chlorella from its habitat).Consider a P.bursaria cell containing zoochlorellae but whose habitat lacks free-living Chlorella.If this cell subsequently undergoes many generations of asexual reproduction,if all of its daughter cells contain roughly the same number of zoochlorellae as it had originally contained,and if the zoochlorellae are all haploid and identical in appearance,then what is true?

What does scientific evidence indicate to be the correct sequence of these events,from earliest to most recent,in the evolution of life on Earth? 1)origin of mitochondria 2)origin of multicellular eukaryotes 3)origin of chloroplasts 4)origin of cyanobacteria 5)origin of fungal-plant symbioses

The motility that permits P.bursaria to move toward a light source is provided by

Which of the following statements concerning protists is correct?

Which pair of alternatives is highlighted by the life cycle of the cellular slime molds,such as Dictyostelium?

Please use the following information to answer the questions below. Giardia intestinalis is an intestinal parasite of humans and other mammals that causes intestinal ailments in most people.It can infect people when they drink water contaminated with feces containing Giardia cysts.Upon ingestion,each cyst releases two motile cells,called trophozoites.These attach to the small intestine's lining via a ventral adhesive disk.The trophozoites anaerobically metabolize glucose from the host's intestinal contents to produce ATP.Reproduction is completely asexual,occurring by longitudinal binary fission of trophozoites,with each daughter cell receiving two haploid nuclei (n = 5).A trophozoite will often encyst as it passes into the large intestine by secreting around itself a case that is resistant to cold,heat,and dehydration. -Giardia's mitosome can be said to be "doubly degenerate," because it is a degenerate form of ________,an organelle that is itself a degenerate form of ________.