Exam 28: Protists

Which of the following statements concerning protists is true?

The cysts of Giardia are most analogous to the

Previously understood similarities that seemed to connect slime molds and fungi are now considered to be ________.

You are given an unknown organism to identify.It is unicellular and heterotrophic.It is motile,using many short extensions of the cytoplasm,each featuring the 9 + 2 filament pattern.It has well-developed organelles and three nuclei,one large and two small.This organism is most likely to be a member of which group?

You are designing an artificial drug-delivery "cell" that can penetrate animal cells.Which of these protist structures should provide the most likely avenue for research along these lines?

What must occur for asexual reproduction to be successful in P.chromatophora? 1)mitosis 2)S phase 3)meiosis 4)equal distribution of cyanelles during cytokinesis

In life cycles with an alternation of generations,multicellular haploid forms alternate with

Which of the following are actual mutualistic partnerships that involve a protist and a host organism?

Ciliates do not

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 4 contains ________.

An individual mixotroph loses its plastids,yet continues to survive.Which of the following most likely accounts for its continued survival?

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?

The best evidence for not classifying the slime moulds as fungi comes from slime moulds'

Which of the following represents the true significance of the finding that the cyanelles of P.chromatophora stem from a different type of cyanobacterium than gave rise to chloroplasts?

If true,which of the following is the best evidence that the cyanelles are providing nutrition (in other words,calories)to the surrounding cercozoan?

Use the following information to answer the questions below. Giardia lamblia is an intestinal parasite of humans and other mammals that causes intestinal ailments in most people who ingest the 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.Infection usually occurs by drinking untreated water that contains cysts. -Giardia's mitosome can be said to be "doubly degenerate," because it is a degenerate form of a ________,an organelle that is itself a degenerate form of a(n)________.

Similar to most amoebozoans,the forams and the radiolarians also have pseudopods,as do some of the white blood cells of animals (monocytes).If one were to erect a taxon that included all organisms that have cells with pseudopods,what would be true of such a taxon?

Use the following information to answer the questions below. Giardia lamblia is an intestinal parasite of humans and other mammals that causes intestinal ailments in most people who ingest the 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.Infection usually occurs by drinking untreated water that contains cysts. -The trophozoites of Giardia were first observed in 1681 in the diarrhea stools of the first known person to view protists with a microscope,a person named

The next few questions refer to the following description and table. Diatoms are encased in Petri-platelike cases (valves)made of translucent hydrated silica whose thickness can be varied.The material used to store excess calories can also be varied.At certain times,diatoms store excess calories in the form of the liquid polysaccharide,laminarin,and at other times as oil.The following are data concerning the density (specific gravity)of various components of diatoms,and of their environment. Specific Gravities of Materials Relevant to Diatoms -Water's density and,consequently,its buoyancy decrease at warmer temperatures.Based on this consideration and using data from the table,at which time of year should one expect diatoms to be storing excess calories mostly as oil?

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 most accurately describes the nutritional mode of healthy P.bursaria?