Exam 28: Protists

Diplomonads,such as Giardia,contain two haploid nuclei per trophozoite.Thus,during the G₁ phase of the cell cycle,there should be a total of how many unreplicated chromosomes per trophozoite,and during the G₂ phase,how many replicated chromosomes per trophozoite?

A large seaweed that floats freely on the surface of deep bodies of water would be expected to lack which of the following?

Biologists have long been aware that the defunct kingdom Protista is polyphyletic.Which of these statements is most consistent with this conclusion?

If we were to apply the most recent technique used to fight potato late blight to the fight against the malarial infection of humans,then we would

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 -Judging from the table and given that water's density and,consequently,its buoyancy decrease at warmer temperatures,in which environment should diatoms (and other suspended particles)sink most slowly?

Which process could have allowed the nucleomorphs of chlorarachniophytes to be reduced,without the net loss of any genetic information?

The mitosome of Giardia has no DNA within it.If it did contain DNA,then what predictions should we be able to make about its DNA? 1)It is linear. 2)It is circular. 3)It has many introns. 4)It has few introns. 5)It is not associated with histone proteins. 6)It is complexed with histone proteins.

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.P.ovalis uses threadlike pseudopods to capture its prey,which it digests internally.Which of the following,if observed,would be the best reason for relabelling P.chromatophora as a mixotroph?

According to the endosymbiotic theory of the origin of eukaryotic cells,how did mitochondria originate?

P.chromatophora secretes around itself a test,or case,of plates made of silica.Which of the following is another rhizarian that would be in competition with P.chromatophora for the silica needed to make these plates,assuming limited quantities of silica in the environment?

Why do photosynthetic protists play a critical role in aquatic ecosystems?

All protists are

Apicomplexans

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

A gelatinous seaweed that grows in shallow,cold water and undergoes heteromorphic alternation of generations is most probably what type of alga?

Reinforced,threadlike pseudopods that can perform phagocytosis are generally characteristic of which group?

The genome of modern chloroplasts is roughly 50% the size of the genome of the cyanobacterium from which it is thought to have been derived.In comparison,the genome of P.chromatophora's cyanelle is only slightly reduced relative to the size of the genome of the cyanobacterium from which it is thought to have been derived.What is a valid conclusion that can be drawn from this comparison?

Which two genera have members that can evade the human immune system by frequently changing their surface proteins? 1)Plasmodium 2)Trichomonas 3)Paramecium 4)Trypanosoma 5)Entamoeba

You are given the task of designing an aerobic,mixotrophic protist that can perform photosynthesis in fairly deep water (for example,250 m deep),and can also crawl about and engulf small particles.With which two of the following structures would you provide your protist? 1)hydrogenosome 2)apicoplast 3)pseudopods 4)chloroplast from red alga 5)chloroplast from green alga

The chloroplasts of all of the following are thought to be derived from ancestral red algae,except those of