Exam 28: Protists

Biologists suspect that endosymbiosis gave rise to mitochondria before plastids partly because

A snail-like,coiled,porous test (shell)of calcium carbonate is characteristic of which group?

You are given the task of designing an aquatic protist that is a primary producer.It cannot swim on its own,yet must stay in well-lit surface waters.It must be resistant to physical damage from wave action.It should be most similar to a(n)

Which of the following is characteristic of ciliates?

Which of the following is correctly described as a primary producer?

Including the membrane of the surrounding vesicle,how many phospholipid (NOT lipopolysaccharide)bilayers should be found around each cyanelle,and which one of these bilayers should have photosystems embedded in it?

A P.bursaria cell that has lost its zoochlorellae is said to be aposymbiotic.It might be able to replenish its contingent of zoochlorellae by ingesting them without subsequently digesting them.Which of the following situations would be most favourable to the reestablishment of resident zoochlorellae,assuming compatible Chlorella are present in P.bursaria's habitat?

Which process in Paramecium results in genetic recombination but no increase in population size?

Green algae differ from land plants in that many green algae

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

The primary treatment for giardiasis (infection with Giardia),as well as for trichomoniasis (infection with Trichomonas vaginalis)and for 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 the parasites' flagella,as the drug's name might imply? 1)It would also harm the flagellated lining of the human intestine. 2)Entamoeba possesses pseudopods,not flagella,yet it is killed by Flagyl. 3)Prokaryotic flagella and eukaryotic flagella are radically different from each other and unlikely to be harmed by the same chemical. 4)Not all anaerobic gut bacteria possess flagella,yet it kills these bacteria.

A crucial photosynthetic gene of the cyanobacterium that gave rise to the cyanelle is called psaE.This gene is present in the nuclear genome of the cercozoan,but is not in the genome of the cyanelle.This is evidence of

In alternation of generation in brown algae,which pair is incorrectly matched?

Given that Flagyl produces only minor side effects (if any)in humans,and given the set of parasites that it kills,Flagyl's mode of action probably involves

Given the putative ancestry of Giardia's mitosome,what should we predict is true of the mitosome?

The following questions refer to the description below. You are given four test tubes,each containing an unknown protist,and your task is to read the following description and match these four protists to the correct test tube. When light,especially red and blue light,is 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 tubes 1,3,and 4 reveals the presence of permanent,membrane-bounded sacs just under the plasma membrane.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 the presence of one large nucleus and one small nucleus in each organism. -Test tube 3 contains ________.

Plastids that are surrounded by more than two membranes are evidence of

During passage through the large intestine,a trophozoite will often secrete a case around itself,forming a cyst.Cysts contain four haploid nuclei.When cysts "hatch" within a new host,two trophozoites are released.Thus,which of the following must happen within the cyst,prior to hatching? 1)meiosis 2)nuclear division 3)S phase 4)binary fission

Use the following information to answer the questions below. Paulinella chromatophora is one of the few cercozoans that is autotrophic,carrying out aerobic photosynthesis with its two elongated "cyanelles." The cyanelles are contained within vesicles of the host cell,and each is derived from a cyanobacterium,though not the same type of cyanobacterium that gave rise to the chloroplasts of algae and plants. -The closest living relative of P.chromatophora is the heterotroph,P.ovalis.What type of evidence permits biologists to make this claim about relatedness?

The next few questions refer to the following description. Healthy individuals of Paramecium bursaria contain photosynthetic algal endosymbionts of the genus Chlorella.When within their hosts,the algae are referred to as zoochlorellae.In aquaria with light coming from only one side,P.bursaria gathers at the well-lit side,whereas other species of Paramecium gather at the opposite side.The zoochlorellae provide their hosts with glucose and oxygen,and P.bursaria provides its zoochlorellae with protection and motility.P.bursaria can lose its zoochlorellae in two ways: (1)if kept in darkness,the algae will die; and (2)if prey items (mostly bacteria)are absent from its habitat,P.bursaria will digest its zoochlorellae. -Which term accurately describes the behaviour of Paramecium species that lack zoochlorellae in an aquarium with light coming from one side only?