Question 1

Which of the following protist groups contain species that form symbiotic associations with unicellular algae?

Accepted Answer

A)  Dinoflagellates 
B)  Actinopods 
C)  Forams 
D)  Diatoms 
E)  Euglenoids 
A)  Dinoflagellates 
B)  Actinopods 
C)  Forams 
D)  Diatoms 
E)  Euglenoids C

Question 2

The phylogeny of protists was traditionally based on nutrition. Which of the following features is NOT used in more recent work to group protists?

Accepted Answer

A)  Morphology 
B)  Biochemistry 
C)  Molecular features 
D)  Gene sequence 
E)  Protein structure 
A)  Morphology 
B)  Biochemistry 
C)  Molecular features 
D)  Gene sequence 
E)  Protein structure E

Question 3

In which of the following groups of protists do typical species have a sexual life cycle that includes motile gametes?

Accepted Answer

A)  Ciliates 
B)  Diatoms 
C)  Red algae 
D)  Water moulds 
E)  Green algae 
A)  Ciliates 
B)  Diatoms 
C)  Red algae 
D)  Water moulds 
E)  Green algae B

Question 4

The malarial parasite

Accepted Answer

A)  contains a plastid 
B)  lacks a plastid. 
C)  retains a vestigial plastid. 
D)  has a double-membrane plastid. 
E)  has a non-photosynthetic plastid. 
A)  contains a plastid 
B)  lacks a plastid. 
C)  retains a vestigial plastid. 
D)  has a double-membrane plastid. 
E)  has a non-photosynthetic plastid.

Question 5

A medical laboratory isolates an intestinal parasite responsible for a local epidemic of severe dysentery. The organism is unicellular with a pair of nuclei and multiple flagella. You would expect that this organism would also have

Accepted Answer

A)  a ventral sucker to allow attachment to the wall of the host's digestive system. 
B)  a conical arrangement of microtubules and secretory structures to enable forced penetration of the cells lining the host's intestine. 
C)  mitochondria with specialised biochemical pathways for respiration in the anaerobic conditions within the digestive system of the host. 
D)  an axostyle of microtubules running along the membrane. 
E)  All of the answers are correct. 
A)  a ventral sucker to allow attachment to the wall of the host's digestive system. 
B)  a conical arrangement of microtubules and secretory structures to enable forced penetration of the cells lining the host's intestine. 
C)  mitochondria with specialised biochemical pathways for respiration in the anaerobic conditions within the digestive system of the host. 
D)  an axostyle of microtubules running along the membrane. 
E)  All of the answers are correct.

Question 6

All Euglenoids

Accepted Answer

A)  have chloroplasts similar to green algae. 
B)  are fresh-water organisms. 
C)  are occasionally heterotrophic. 
D)  swim using a single long flagellum. 
E)  are parasitic. 
A)  have chloroplasts similar to green algae. 
B)  are fresh-water organisms. 
C)  are occasionally heterotrophic. 
D)  swim using a single long flagellum. 
E)  are parasitic.

Question 7

You have been asked to identify an organism that is a unicellular, free-living heterotroph. It has a single flagellum and is surrounded by a basket-shaped structure composed of silica strips. You would conclude that the organism is a

Accepted Answer

A)  choanoflagellate. 
B)  diatom. 
C)  dinoflagellate. 
D)  euglenoid. 
E)  apicomplexa. 
A)  choanoflagellate. 
B)  diatom. 
C)  dinoflagellate. 
D)  euglenoid. 
E)  apicomplexa.

Question 8

Radiolarians are single-celled radially symmetrical protists with elaborate skeletons commonly composed of

Accepted Answer

A)  cellulose. 
B)  silica. 
C)  calcium carbonate. 
D)  chitin. 
E)  interlocking proteinaceous strips. 
A)  cellulose. 
B)  silica. 
C)  calcium carbonate. 
D)  chitin. 
E)  interlocking proteinaceous strips.

Question 9

A molecular biologist is studying the physical structure of DNA from various eukarya when, much to her surprise, she notices the DNA from one organism is not packaged in nucleosomes. What type of organism could this be?

Accepted Answer

A)  Diatom 
B)  Phaeophyte 
C)  Oomycete 
D)  Dinoflagellate 
E)  Cilliate 
A)  Diatom 
B)  Phaeophyte 
C)  Oomycete 
D)  Dinoflagellate 
E)  Cilliate

Question 10

Two scientists working in the field discover a small slug-like creature which is approximately 1mm long. The two scientists disagree on the origins of the organism: one believes it to be a true mollusc, the other suspects it could be a pseudoplasmodium. How could it be most simply determined what the true nature of the organism is?

Accepted Answer

A)  Place the 'slug' in an environment favourable to cellular slime moulds with sufficient food sources and observe if the slug differentiates into a fruiting body. 
B)  Perform DNA analysis and look for molecular markers specific to molluscs. 
C)  Dissect the slug under microscopy and analyse the internal anatomy of the organism. 
D)  Place the 'slug' in an environment favourable to cellular slime moulds with sufficient food sources and observe if the slug differentiates into a mass of individual amoeba. 
E)  Using a classical Linnaean system, use physiological and morphological features to key out the organism to genus and species. 
A)  Place the 'slug' in an environment favourable to cellular slime moulds with sufficient food sources and observe if the slug differentiates into a fruiting body. 
B)  Perform DNA analysis and look for molecular markers specific to molluscs. 
C)  Dissect the slug under microscopy and analyse the internal anatomy of the organism. 
D)  Place the 'slug' in an environment favourable to cellular slime moulds with sufficient food sources and observe if the slug differentiates into a mass of individual amoeba. 
E)  Using a classical Linnaean system, use physiological and morphological features to key out the organism to genus and species.

Question 11

The photosynthetic eukaryotes

Accepted Answer

A)  form a monophyletic group because it appears likely that a single endosymbiotic event produced the many different-coloured chloroplasts observed in protists and plants. 
B)  contain chloroplasts that have evolved from the cyanelles of Glaucophytes. 
C)  share an acquired organelle rather than a common ancestor. 
D)  have diverged into three distinct lineages: the 'green lineage' (green algae and plants), the 'brown lineage' (brown algae, diatoms and other chromists), and the 'red lineage' (red algae and dinoflagellates). 
E)  All the answers are correct. 
A)  form a monophyletic group because it appears likely that a single endosymbiotic event produced the many different-coloured chloroplasts observed in protists and plants. 
B)  contain chloroplasts that have evolved from the cyanelles of Glaucophytes. 
C)  share an acquired organelle rather than a common ancestor. 
D)  have diverged into three distinct lineages: the 'green lineage' (green algae and plants), the 'brown lineage' (brown algae, diatoms and other chromists), and the 'red lineage' (red algae and dinoflagellates). 
E)  All the answers are correct.

Question 12

A biologist discovers an aquatic organism that is unicellular with well-developed organelles, including two kinds of nuclei. The organism is an active predator that engulfs smaller unicellular organisms. The biologist also observes that occasionally individuals are found in pairs that remain connected for several hours. Based on this information, the biologist concludes that the organism is a

Accepted Answer

A)  euglenoid. 
B)  ciliate. 
C)  kinetoplast. 
D)  heterokont. 
E)  dinoflagellate. 
A)  euglenoid. 
B)  ciliate. 
C)  kinetoplast. 
D)  heterokont. 
E)  dinoflagellate.

Question 13

Heliozoans are radially symmetrical unicells with intricate siliceous skeletons, found mainly in freshwater plankton. They feed by engulfing food particles that become trapped on the surface of numerous thin ray-like extensions of the cytoplasm that radiate from the surface. Each cytoplasmic extension is made rigid by a central rod of microtubules. Based on this description, Heliozoans would be classified as

Accepted Answer

A)  forams. 
B)  actinopods. 
C)  rhizopods. 
D)  chrysophytes. 
E)  diatoms. 
A)  forams. 
B)  actinopods. 
C)  rhizopods. 
D)  chrysophytes. 
E)  diatoms.

Question 14

Sponges have collar cells called choanocytes that consist of a central flagellum surrounded by a microvilli collar. What organism does this bear a striking resemblance too?

Accepted Answer

A)  Phytophthora 
B)  Slime mould 
C)  Choanoflagellate 
D)  Cercozoa 
E)  Euglenoid 
A)  Phytophthora 
B)  Slime mould 
C)  Choanoflagellate 
D)  Cercozoa 
E)  Euglenoid

Question 15

Parabasalids are a small group of protists involved in parasitic or commensal relationships with animals. Parabasalids are unusual in that

Accepted Answer

A)  they lack mitochondria. 
B)  they have plasmids contain cytochromea. 
C)  their mitochondria lack DNA and carry out anaerobic respiration. 
D)  they have a single mitochondrion, containing a large rod-shaped mass of DNA, at the base of the flagella. 
E)  their mitochondria are surrounded by three membranes, suggesting that the ancestors of Parabasalids gained their mitochondria by secondary endosymbiosis. 
A)  they lack mitochondria. 
B)  they have plasmids contain cytochromea. 
C)  their mitochondria lack DNA and carry out anaerobic respiration. 
D)  they have a single mitochondrion, containing a large rod-shaped mass of DNA, at the base of the flagella. 
E)  their mitochondria are surrounded by three membranes, suggesting that the ancestors of Parabasalids gained their mitochondria by secondary endosymbiosis.

Question 16

Typical heterokont protists have plastids that were almost certainly acquired through secondary endosymbioses. In addition to this,

Accepted Answer

A)  heterokonts can be both photosynthetic, in the presence of light, and heterotrophic, in the dark. 
B)  heterokonts have two different kinds of nuclei, the micronucleus, involved in sexual reproduction and the macronucleus, which controls the everyday functions of the cell. 
C)  heterokont plastids contain a nucleomorph, a remnant of the nucleus of the secondary endosymbiont. 
D)  most heterokonts have lost their plastid and reverted to heterotrophy. 
E)  heterokonts have two flagella, an anteriorly directed, hairy or tinsel flagellum and a posteriorly directed, whiplash or smooth flagellum. 
A)  heterokonts can be both photosynthetic, in the presence of light, and heterotrophic, in the dark. 
B)  heterokonts have two different kinds of nuclei, the micronucleus, involved in sexual reproduction and the macronucleus, which controls the everyday functions of the cell. 
C)  heterokont plastids contain a nucleomorph, a remnant of the nucleus of the secondary endosymbiont. 
D)  most heterokonts have lost their plastid and reverted to heterotrophy. 
E)  heterokonts have two flagella, an anteriorly directed, hairy or tinsel flagellum and a posteriorly directed, whiplash or smooth flagellum.

Question 17

Cryptomonads differ from other photosynthetic protists in that they

Accepted Answer

A)  acquired their chloroplasts by primary endosymbiosis. 
B)  store the products of photosynthesis outside the chloroplast. 
C)  have a second, much-reduced nucleus associated with the chloroplast. 
D)  have reticulopodia linking individual cells in an amoeboid plasmodium. 
E)  contain plastids with cytochrome a and c 
A)  acquired their chloroplasts by primary endosymbiosis. 
B)  store the products of photosynthesis outside the chloroplast. 
C)  have a second, much-reduced nucleus associated with the chloroplast. 
D)  have reticulopodia linking individual cells in an amoeboid plasmodium. 
E)  contain plastids with cytochrome a and c

Question 18

Haptophytes

Accepted Answer

A)  are extremely abundant in inland waters, frequently forming massive blooms. 
B)  contain a haptonema, s thread-like extension between the flagella, which is used to capture prey. 
C)  are close relatives of the chrysophytes as they also have heterokont flagellation. 
D)  contain spectacular, star-shaped silica skeletons. 
E)  use starch as a storage molecule. 
A)  are extremely abundant in inland waters, frequently forming massive blooms. 
B)  contain a haptonema, s thread-like extension between the flagella, which is used to capture prey. 
C)  are close relatives of the chrysophytes as they also have heterokont flagellation. 
D)  contain spectacular, star-shaped silica skeletons. 
E)  use starch as a storage molecule.

Question 19

Chlorophytes and phaeophytes share all of the following characteristics EXCEPT

Accepted Answer

A)  the presence of chlorophyll a. 
B)  the absence of a vascular system. 
C)  a wide range of commercial uses. 
D)  motile gametes with one smooth and one hairy flagellum. 
E)  mainly marine and multicellular. 
A)  the presence of chlorophyll a. 
B)  the absence of a vascular system. 
C)  a wide range of commercial uses. 
D)  motile gametes with one smooth and one hairy flagellum. 
E)  mainly marine and multicellular.

Question 20

Which of the following describes the skeleton of a dinoflagellate?

Accepted Answer

A)  An elaborate array of trumpet-shaped calcium carbonate plates, forming a sphere. 
B)  A multichambered shell made of organic material hardened with calcium carbonate. The spirally arranged chambers have many tiny pores. 
C)  Spherical, with a distinctive equatorial constriction. The surface is covered by a complex pattern of projecting ridges, reinforced by internal plates of cellulose. 
D)  Long slender radial projections with scales of silica. 
E)  A pair of glass-like valves that fit together like the two halves of a Petri dish. The surface is highly ornamented with pores and spines. 
A)  An elaborate array of trumpet-shaped calcium carbonate plates, forming a sphere. 
B)  A multichambered shell made of organic material hardened with calcium carbonate. The spirally arranged chambers have many tiny pores. 
C)  Spherical, with a distinctive equatorial constriction. The surface is covered by a complex pattern of projecting ridges, reinforced by internal plates of cellulose. 
D)  Long slender radial projections with scales of silica. 
E)  A pair of glass-like valves that fit together like the two halves of a Petri dish. The surface is highly ornamented with pores and spines.

Exam 36: The Protists

Which of the following protist groups contain species that form symbiotic associations with unicellular algae?

The phylogeny of protists was traditionally based on nutrition. Which of the following features is NOT used in more recent work to group protists?

In which of the following groups of protists do typical species have a sexual life cycle that includes motile gametes?

The malarial parasite

A medical laboratory isolates an intestinal parasite responsible for a local epidemic of severe dysentery. The organism is unicellular with a pair of nuclei and multiple flagella. You would expect that this organism would also have

All Euglenoids

You have been asked to identify an organism that is a unicellular, free-living heterotroph. It has a single flagellum and is surrounded by a basket-shaped structure composed of silica strips. You would conclude that the organism is a

Radiolarians are single-celled radially symmetrical protists with elaborate skeletons commonly composed of

A molecular biologist is studying the physical structure of DNA from various eukarya when, much to her surprise, she notices the DNA from one organism is not packaged in nucleosomes. What type of organism could this be?

The photosynthetic eukaryotes

Sponges have collar cells called choanocytes that consist of a central flagellum surrounded by a microvilli collar. What organism does this bear a striking resemblance too?

Parabasalids are a small group of protists involved in parasitic or commensal relationships with animals. Parabasalids are unusual in that

Typical heterokont protists have plastids that were almost certainly acquired through secondary endosymbioses. In addition to this,

Cryptomonads differ from other photosynthetic protists in that they

Haptophytes

Chlorophytes and phaeophytes share all of the following characteristics EXCEPT

Which of the following describes the skeleton of a dinoflagellate?

Nature of Molecules

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