Question 1

The data graphed in Figure 29.3 could be an artifact if latrunculin A kills this species of diatoms (i.e.,that may be why the cells are not moving).Which of the following would be the best evidence that latrunculin A is not killing the cells?

Accepted Answer

A) When the toxin was washed off the culture,the cells began to move again. 
B) There were still a small percentage of motile cells in the culture treated with the toxin. 
C) Most of the cells in the control were moving,indicating that they were alive. 
D) When the toxin was applied to another species of diatom,25% of them continued to move.

Question 2

By examining the phylogenetic tree diagrammed above,what conclusion can you draw about the species G.microti?

Accepted Answer

A) It evolved before G.intestinalis. 
B) It is more closely related to G.muris than to G.intestinalis. 
C) It should not be labeled a species distinct from G.intestinalis. 
D) It is part of a monophyletic group that also includes G.intestinalis. 
E) None of the above can be concluded from the data provided.

Question 3

How are algal blooms (red tides)typically harmful to humans?

Accepted Answer

A) The blooms destroy shellfish and other food sources for humans. 
B) Shellfish eat the harmful algae,and humans eat the contaminated shellfish. 
C) Humans can become poisoned when swimming in contaminated water. 
D) All of the above answers apply.

Question 4

The manufacture of which of the following products involves using materials that once belonged to a protist?

Accepted Answer

A) cosmetics 
B) filters 
C) chalk 
D) marble 
E) all of the above

Question 5

Which of the following movements are matched correctly with the appendage that facilitates that movement in protists?

Accepted Answer

A) cell crawling;flagella 
B) swimming;pseudopodia 
C) cell crawling;cilia 
D) swimming;flagella

Question 6

Alternation of generations occurs in protists.Which of the following represents the correct sequence of events for this mode of reproduction?

Accepted Answer

A) gametophyte → gamete → fusion → sporophyte → spore → gametophyte 
B) sporophyte → spore fusion → gametophyte → gamete → sporophyte 
C) gametophyte → fusion → sporophyte → spore → gamete → gametophyte 
D) gamete → fusion → gametophyte → spore → sporophyte → gamete

Question 7

Which of the following protists causes the human disease malaria?

Accepted Answer

A) Giardia 
B) Plasmodium 
C) Trichomonas 
D) Leishmania

Question 8

Phytoplankton is comprised of photosynthetic protists and bacteria.For the most part,humans do not consume phytoplankton.Why,then,are they important to humans?

Accepted Answer

A) They are food for many marine organisms that humans eat. 
B) They release a lot of carbon dioxide into the atmosphere. 
C) They cause serious illness in humans. 
D) They are not important to humans.

Question 9

A particular species of protist has obtained a chloroplast via secondary endosymbiosis.How can you tell?

Accepted Answer

A) The chloroplasts have both nuclear and cyanobacterial genes. 
B) The chloroplasts are exceptionally small. 
C) The chloroplasts have three or four membranes. 
D) The chloroplasts have only a single pigment.

Question 10

Which of the following best describes what scientists (the Bell research group)concluded about the effect of atmospheric CO₂ increases on phytoplankton's primary productivity?

Accepted Answer

A) After 1000 generations,phytoplankton showed a consistent significant increase in primary productivity. 
B) After 1000 generations,phytoplankton showed a consistent significant decrease in primary productivity. 
C) After 1000 generations,phytoplankton showed a moderate increase in primary productivity. 
D) After 1000 generations,phytoplankton will not show an increase in primary productivity.

Question 11

What is meant by the term "high-selected" lines in the phytoplankton experiment?

Accepted Answer

A) lines of phyloplankton that had strong environmental selection pressures 
B) lines of phytoplankton that were grown in high CO₂ conditions,compared to other phytoplankton lines 
C) lines of phytoplankton that were allowed to grow at a faster rate than other lines of phytoplankton 
D) All of the above. 
E) Both A and B.

Question 12

Figure 29.1 Use the following information to answer the corresponding question(s).
Giardia intestinalis can cause disease in several different mammalian species, including humans. Giardia organisms (G. intestinalis)that infect humans are similar morphologically to those that infect other mammals; thus, they have been considered a single species, though other species in the Giardia genus infect other organisms. However, G. intestinalis has been divided into different subgroups based on their host and a few other characteristics.
In 1999, a DNA sequence comparison study tested the hypothesis that these subgroups actually constitute different species. The following phylogenetic tree was constructed from the sequence comparison of rRNA from several subgroups of G. intestinalis and a few other morphologically distinct species of Giardia. The researchers concluded that the subgroups of Giardia are sufficiently different from one another genetically that they could be considered different species. (T. Monis et al. 1999. Molecular systematics of the parasitic protozoan Giardia intestinalis. Mol. Biol. Evol. 16[9]:1135-44.)
 
-According to the phylogenetic tree in the figure above,Giardia intestinalis constitutes a ________ group.

Accepted Answer

A) paraphyletic 
B) monophyletic 
C) polyphyletic

Question 13

Imagine there are 25 different species of protists living in a tide pool.Some of these species reproduce both sexually and asexually,and some of them can reproduce only asexually.The pool gradually becomes infested with disease-causing viruses and bacteria.Which species are more likely to thrive in the changing environment?

Accepted Answer

A) the sexually reproducing species 
B) the asexually reproducing species

Question 14

Which of the following statements best describes the term synapomorphy?

Accepted Answer

A) A trait that is shared by more than one monophyletic group. 
B) A trait common in a single monophyletic group,but not generally found outside of that group. 
C) The state of having several traits in common with different monophyletic groups. 
D) A trait that evolved in several different monophyletic groups simultaneously.

Question 15

What is the major distinguishing feature of Amoebozoa?

Accepted Answer

A) Cells have chloroplasts with a double membrane. 
B) Cells lack cell walls and so,when portions of the cell extend for movement,large lobes are formed. 
C)  Cells lack cell walls and so,when portions of the cell extend for movement,they are slender in shape. 
D) Cells have pronounced "feeding grooves" for digesting prey or organic debris.

Question 16

You isolate a previously undescribed protist species from the soil outside your residence.Which of the following technique(s)would provide useful data for describing,classifying,and naming this new species?

Accepted Answer

A) PCR 
B) light microscopy 
C) gene sequence comparison 
D) electron microscopy 
E) all of the above

Exam 29: Protists

The data graphed in Figure 29.3 could be an artifact if latrunculin A kills this species of diatoms (i.e.,that may be why the cells are not moving) .Which of the following would be the best evidence that latrunculin A is not killing the cells?