28.6 Protists play key roles in ecological communities Flashcards
42) The best evidence for not classifying the slime molds as fungi comes from slime moldsʹ
A) DNA sequences.
B) nutritional modes.
C) choice of habitats.
D) physical appearance.
E) reproductive methods.
A) DNA sequences.
43) Which pair of alternatives is highlighted by the life cycle of the cellular slime molds, such as
Dictyostelium?
A) prokaryotic or eukaryotic
B) plant or animal
C) unicellular or multicellular
D) diploid or haploid
E) autotroph or heterotroph
C) unicellular or multicellular
44) Which of the following correctly pairs a protist with one of its characteristics?
A) diplomonads : micronuclei involved in conjugation
B) ciliates : pseudopods
C) apicomplexans : parasitic
D) gymnamoebas : calcium carbonate test
E) foraminiferans : abundant in soils
C) apicomplexans : parasitic
45) Which of the following statements concerning protists is false?
A) All protists are eukaryotic organisms; many are unicellular or colonial.
B) The primary organism that transmits malaria to humans by its bite is the tsetse fly.
C) All apicomplexans are parasitic.
D) Cellular slime molds have an amoeboid stage that may be followed by a stage during which spores are produced.
E) Euglenozoans that are mixotrophic contain chloroplasts.
B) The primary organism that transmits malaria to humans by its bite is the tsetse fly.
46) Which of the following is correctly described as a primary producer?
A) oomycete
B) kinetoplastid
C) apicomplexan
D) diatom
E) radiolarian
D) diatom
47) A certain unicellular eukaryote has a siliceous (glasslike) shell and autotrophic nutrition. To
which group does it belong?
A) dinoflagellates
B) diatoms
C) brown algae
D) radiolarians
E) oomycetes
B) diatoms
48) You are given the task of designing an aerobic, mixotrophic protist that can perform
photosynthesis in fairly deep water (e.g., 250 m deep), and can also crawl about and engulf
small particles. With which two of these structures would you provide your protist?
1. hydrogenosome
2. apicoplast
3. pseudopods
4. chloroplast from red alga
5. chloroplast from green alga
A) 1 and 2
B) 2 and 3
C) 2 and 4
D) 3 and 4
E) 4 and 5
D) 3 and 4
49) 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)
A) diatom.
B) dinoflagellate.
C) apicomplexan.
D) red alga.
E) radiolarian.
A) diatom.
50) Some protists, formerly united as the ʺamitochondriateʺ clade, have recently been shown to
be rather diverse. Some of them possess neither mitochondria nor mitochondrial genes (and
have been classified as fungi). Others possess no mitochondria, but do have mitochondrial
genes in their nuclear genome. Still others have modified mitochondria (viz. mitosomes or
hydrogenosomes). Which statement(s) represent(s) consequences of these recent findings?
1. The amitochondriates do not comprise a true clade.
2. The ʺamitochondriate hypothesisʺ concerning the root of the eukaryotic tree has been
strengthened.
3. Just as there is a diversity of cyanobacterial descendants among eukaryotes, so too is
there a diversity of alpha-proteobacterial descendants among the eukaryotes.
4. If the amitochondriate organisms continued to be recognized as a taxon, this taxon
would be polyphyletic.
5. Horizontal gene transfer involving mitochondrial genes has occurred in some
amitochondriate organisms.
A) 1 only
B) 1 and 4
C) 2 and 3
D) 1, 3, and 5
E) all except 2
E) all except 2
51) Similar to most amoebozoans, the forams and the radiolarians also have pseudopods, as do
the white blood cells of animals. If one were to erect a taxon that included all organisms
that have cells with pseudpods, what would be true of such a taxon?
A) It would be polyphyletic.
B) It would be paraphyletic.
C) It would be monophyletic.
D) It would include all eukaryotes.
A) It would be polyphyletic.
52) You are designing an artificial drug-delivery ʺcellʺ that can penetrate animal cells. Which of
these protist structures should provide the most likely avenue for research along these
lines?
A) pseudopods
B) apical complex
C) excavated feeding grooves
D) nucleomorphs
E) mitosomes
B) apical complex
53) A gelatinous seaweed that grows in shallow, cold water and undergoes heteromorphic
alternation of generations is most probably what type of alga?
A) red
B) green
C) brown
D) yellow
C) brown
1) Plastids that are surrounded by more than two membranes are evidence of
A) evolution from mitochondria.
B) fusion of plastids.
C) origin of the plastids from archaea.
D) secondary endosymbiosis.
E) budding of the plastids from the nuclear envelope.
D) secondary endosymbiosis.
2) Biologists suspect that endosymbiosis gave rise to mitochondria before plastids partly
because
A) the products of photosynthesis could not be metabolized without mitochondrial enzymes.
B) all eukaryotes have mitochondria (or their remnants), whereas many eukaryotes do not have plastids.
C) mitochondrial DNA is less similar to prokaryotic DNA than is plastid DNA.
D) without mitochondrial CO2 production, photosynthesis could not occur.
E) mitochondrial proteins are synthesized on cytosolic ribosomes, whereas plastids utilize their own ribosomes.
B) all eukaryotes have mitochondria (or their remnants), whereas many eukaryotes do not have plastids.
3) Which group is incorrectly paired with its description?
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
C) red algae–acquired plastids by secondary endosymbiosis
