27. Protists

Which of these groups includes unicellular organisms that, due to the structure of their cell walls, can withstand pressures equal to the pressure under each leg of a table supporting an elephant?

What role do diatoms play in the global carbon balance affecting global warming?

Which of the following groups of algae is/are most closely related to land plants?

On some areas of the seafloor, one could observe an "ooze" that is hundreds of meters thick. What creates this ooze?

Many species of red algae are adapted to deeper water due to the fact that __________.

The most important primary producers in marine ecosystems are .

Which group is incorrectly paired with its description?a. diatoms—important producers in aquatic communitiesb. red algae—eukaryotes that acquired plastids by secondary endosymbiosisc. apicomplexans—unicellular parasites with intricate life cyclesd. diplomonads—unicellular eukaryotes with modified mitochondria

What is the role of PEP carboxylase in C4 and CAM plants?a. It fixes CO2 into an organic acid.b. It produces ATP for the Calvin cycle.c. It replaces rubicso in the Calvin cycle.d. It releases CO2 from organic acids.

According to the phylogeny presented in this chapter, which protists are in the same eukaryotic supergroup as plants?a. green algaeb. dinoflagellatesc. red algaed. both A and C

How can dinoflagellates be harmful to humans?a. They are transmitted by mosquitoes and cause malaria.b. They produce toxins that can be absorbed by clams and other shellfish which, when eaten by people, can lead to paralytic shellfish poisoning.c. They cause amoebic dysentery which leads to severe diarrhea and dehydration.d. They are transmitted by tsetse flies and cause 'sleeping sickness.'

How can dinoflagellates be harmful to humans?a. They are transmitted by mosquitoes and cause malaria.b. They produce toxins that can be absorbed by clams and other shellfish which, when eaten by people, can lead to paralytic shellfish poisoning.c. They cause amoebic dysentery which leads to severe diarrhea and dehydration.d. They are transmitted by tsetse flies and cause 'sleeping sickness.'

Which of the following members of the SAR supergroup is incorrectly paired with its clade?a. stramenopiles—brown algaeb. alveolates—parasites such as Plasmodiumc. alveolates—dinoflagellatesd. Rhizaria—diatoms

Based on the phylogenetic tree in Figure 28.2, which of the following statements is correct?a. The most recent common ancestor of Excavata is older than that of SAR.b. The most recent common ancestor of SAR is older than that of Unikonta.c. The most basal (first to diverge) eukaryotic supergroup cannot be determined.d. Excavata is the most basal eukaryotic supergroup.

In step 3 of the citric acid cycle, the enzyme isocitrate dehydrogenase is regulated by NADH. Compare and contrast the regulation of this enzyme with the regulation of phosphofructokinase in glycolysis.

Apply what you know of the relationship between the light-capturing reactions and the Calvin cycle to calculate the number of photons used to produce a new G3P and regenerate RuBP. (Assume 1 ATP is produced for each pair of electrons used to form NADPH.)