Question 1

Diatoms are mostly asexual members of the phytoplankton. Diatoms lack any organelles that might have the 9 + 2 pattern. They obtain their nutrition from functional chloroplasts, and each diatom is encased within two porous, glasslike valves. Which question would be most important for one interested in the day-to-day survival of individual diatoms?

Accepted Answer

A)  How does carbon dioxide get into these protists with their glasslike valves? 
B)  How do diatoms get transported from one location on the water's surface layers to another location on the surface? 
C)  How do diatoms with their glasslike valves keep from sinking into poorly lit waters? 
D)  How do diatoms with their glasslike valves avoid being shattered by the action of waves? 
E)  How do diatom sperm cells locate diatom egg cells?

Question 2

Which of the following was derived from an ancestral cyanobacterium?

Accepted Answer

A)  chloroplast 
B)  mitochondrion 
C)  hydrogenosome 
D)  mitosome 
E)  Two of the responses above are correct.

Question 3

If true, which of the following would be most important in determining whether P. chromatophora's cyanelle is still an endosymbiont, or is an organelle, as the term cyanelle implies?

Accepted Answer

A)  If P. chromatophora is less fit without its cyanelle than with it. 
B)  If the cyanelle is less fit without the host cercozoan than with it. 
C)  If there is ongoing metabolic cooperation between the cyanelle and the host cercozoan. 
D)  If the magnesium-containing porphyrin ring in the cyanelle's chlorophyll molecules is built by the cyanelle, whereas the organic portion of the chlorophyll molecules is built by the host cercozoan. 
E)  If there has been movement of genes from the cyanelle genome to the nuclear genome, such that these genes are no longer present in the cyanelle genome.

Question 4

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

Accepted Answer

A)  radiolarians and forams 
B)  gymnamoebas 
C)  entamoebas 
D)  amoeboid stage of cellular slime molds 
E)  oomycetes

Question 5

Which of the following statements about dinoflagellates is true?

Accepted Answer

A)  They possess two flagella. 
B)  All known varieties are autotrophic. 
C)  Their walls are usually composed of silica plates. 
D)  Many types lack mitochondria. 
E)  Their dead cells accumulate on the seafloor, and are mined to serve as a filtering material.

Question 6

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

Accepted Answer

A)  Many species within this kingdom were once classified as monerans. 
B)  Animals, plants, and fungi arose from different protist ancestors. 
C)  The eukaryotic condition has evolved more than once among the protists. 
D)  Chloroplasts among various protists are similar to those found in prokaryotes. 
E)  Some protists, all animals, and all fungi share a protist common ancestor, but these protists, animals, and fungi are currently assigned to three different kingdoms.

Question 7

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

Accepted Answer

A)  prokaryotic or eukaryotic 
B)  unicellular or multicellular 
C)  diploid or haploid 
D)  autotroph or heterotroph

Question 8

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

Accepted Answer

A)  1 only 
B)  1 and 2 
C)  2 and 3 
D)  2 and 4 
E)  2, 3, and 4

Question 9

A biologist discovers an alga that is marine, multicellular, and lives at a depth reached only by blue light. This alga probably belongs to which group?

Accepted Answer

A)  red algae 
B)  brown algae 
C)  green algae 
D)  dinoflagellates 
E)  golden algae

Question 10

Which group is incorrectly paired with its description?

Accepted Answer

A)  rhizarians-morphologically diverse group defined by DNA similarities 
B)  diatoms-important producers in aquatic communities 
C)  red algae-acquired plastids by secondary endosymbiosis 
D)  apicomplexans-parasites with intricate life cycles 
E)  diplomonads-protists with modified mitochondria

Question 11

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

Accepted Answer

A)  1 only 
B)  3 only 
C)  1 and 2 
D)  1 and 3 
E)  2 and 3

Question 12

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

Accepted Answer

A)  apicomplexans-internal parasites 
B)  golden algae-planktonic producers 
C)  euglenozoans-unicellular flagellates 
D)  ciliates-red tide organisms 
E)  entamoebas-ingestive heterotrophs

Question 13

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

Accepted Answer

A)  oomycete 
B)  kinetoplastid 
C)  apicomplexan 
D)  diatom 
E)  radiolarian

Question 14

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

Accepted Answer

A)  red 
B)  green 
C)  brown 
D)  yellow

Question 15

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)

Accepted Answer

A)  diatom. 
B)  dinoflagellate. 
C)  apicomplexan. 
D)  red alga. 
E)  radiolarian.

Question 16

Why is the filamentous morphology of the water molds considered a case of convergent evolution?

Accepted Answer

A)  Water molds evolved from filamentous fungi. 
B)  Body shape reflects ancestor-descendant relationships among organisms. 
C)  In both cases, filamentous shape is an adaptation for the absorptive nutritional mode of a decomposer. 
D)  Filamentous body shape is evolutionarily ancestral for all eukaryotes. 
E)  Both the first and second responses above are correct.

Exam 28: Protists