Deck 26: Protists

Question 1

Which of the following is not true of the protists?

A) they are unicellular, colonial, coenocytic, or simple multicellular organisms
B) their cilia and flagella have a 9 + 2 arrangement of microtubules
C) they are prokaryotic, as bacteria and archaea are
D) some are free-living, and some are endosymbionts
E) most are aquatic and live in the ocean or in freshwater ponds

Answer 1

Protists are a group of eukaryotic organisms that primarily live in aquatic habitats. They have many body forms as well as many types of reproduction and nutrition.
(a) They are unicellular, colonial, coenocytic, or simple multicellular organisms. This answer correctly describes protists, so it is incorrect.
(b) Their cilia and flagella have a 9+2 arrangement of microtubules. This answer correctly describes protists, so it is incorrect.
(c) They are prokaryotic, as bacteria and archaea are. This does NOT correctly describe protists, so this is the correct answer. Protists are eukaryotic organisms.
(d) Some are free-living, and some are endosymbionts. This answer correctly describes protists, so it is incorrect.
(e) Most are aquatic and live in the ocean or freshwater ponds.
So the correct answer choice is (c).

Question 2

Molecular evidence supports the view that all plastids evolved from an ancient

A) cyanobacterium
B) archaean
C) diplomonad
D) apicomplexan
E) unikont

Answer 2

Plastids are an organelle found in plant cells. They are used for photosynthesis. They are thought to have come from ancient cyanobacteria that underwent endosymbiosis.
(a) Cyanobacterium. This is the correct answer as plastids are believed to have come from the endosymbiosis of cyanobacteria.
(b) Archaean. This is incorrect as plastids are believed to have come from the endosymbiosis of cyanobacteria.
(c) Diplomonad. This is incorrect as plastids are believed to have come from the endosymbiosis of cyanobacteria.
(d) Apicomplexan. This is incorrect as plastids are believed to have come from the endosymbiosis of cyanobacteria.
(e) Unikont. This is incorrect as plastids are believed to have come from the endosymbiosis of cyanobacteria.
So the correct answer is (a).

Question 3

Forams

A) are endosymbionts that live in many marine invertebrates
B) were responsible for the Irish potato famine in the 19th century
C) secrete many-chambered tests with pores through which cytoplasmic extensions project
D) have numerous axopods that may aid in trapping and holding prey
E) have numerous cilia to direct food into the oral groove

Answer 3

Foram is the shortened version of foraminiferans which are marine rhizarians. These specific rhizarians produce intricate "tests" (a.k.a. hard outer shells) that secrete a chalky, outer shell that has holes in it through which cytoplasm projections extend out into the water.
(a) Are endosymbionts that live in many marine invertebrates. This is incorrect because forams are marine, but they live in the environment, not in a host species.
(b) Were responsible for the Irish potato famine in the 19 th century. This is incorrect as the potato famine was due to potato blight which is a fungus.
(c) Secrete many-chambered tests with pores through which cytoplasmic extensions project. This is the correct answer as it correctly describes forams.
(d) Have numerous axopods that may aid in trapping and holding prey. This is incorrect because it describes actinopods.
(e) Have numerous cilia to direct food into the oral groove. This is incorrect because it describes ciliates.
So the correct answer choice is (c).

Question 4

Paramecium and other ciliates oft en display a sexual phenomenon called

A) oogamy
B) conjugation
C) serial endosymbiosis
D) red tide
E) alternation of generations

Question 5

Parasitic alveolates that form spores at some stage in their life belong to which group?

A) actinopods
B) ciliates
C) coccolithophorids
D) apicomplexans
E) dinoflagellates

Question 6

Malaria

A) is transmitted by the bite of a female tsetse fly
B) is caused by a parasitic flagellate, Giardia intestinalis
C) is a serious form of amoebic dysentery caused by Entamoeba histolytica
D) is caused by an apicomplexan that spends part of its life cycle in the Anopheles mosquito and part in humans
E) is transmitted when people drink water tainted by a red tide

Question 7

Photosynthetic protists with shells composed of two halves that fit together like a petri dish are

A) golden algae
B) diatoms
C) euglenoids
D) brown algae
E) forams

Question 8

The pigments, energy reserve products, and cell walls found in land plants are also characteristic of

A) green algae
B) brown algae
C) golden algae
D) diatoms
E) euglenoids and diatoms

Question 9

Kelps are _____ with multicellular bodies differentiated into blades, stipes, holdfasts, and gas-filled floats.

A) golden algae
B) diatoms
C) euglenoids
D) brown algae
E) red algae

Question 10

Cellular slime molds

A) include Physarum and Phytophthora
B) are more closely related to bacteria than are any other protists
C) are responsible for late blight of potatoes, which led to starvation in Ireland in the 1840s
D) have double-gene fusion
E) form a slug when cells aggregate in response to cyclic AMP

Question 11

Water molds reproduce asexually by forming _____ and sexually by forming _____.

A) oospores; holdfasts
B) zoospores; zooxanthellae
C) zoospores; oospores
D) holdfasts; oospores
E) oospores; zoospores

Question 12

visualize Draw simple sketches of a Euglena and a Paramecium. Choose the appropriate structures for each organism from the following list and label them in your drawings: flagellum, cilia, chloroplast, mitochondrion, nucleus, macronucleus, micronucleus, contractile vacuole, pellicle, food vacuole.

Question 13

EVOLUTION LINK. Why are the protists considered paraphyletic? Use Figure to help explain your answer.
FIGURE Evolutionary relationships among eukaryotes

Question 14

ANALYZING DATA. In the darkfield LM of unicellular choanoflagellates (at right), actin has been stained red, tubulin green, and DNA blue. Identify the cell parts that contain each of these chemical materials.

Question 15

science, technology, and society Use examples associated with the malaria parasite, Plasmodium , to illustrate why an understanding of evolution is indispensable to modern medical research. ( Hint: Be sure to include serial endosymbiosis and drug resistance in your answer.)