Question 1

Which of the following statements best describes the process of secondary endosymbiosis in protist evolution?

Accepted Answer

A eukaryotic cell engulfs another eukaryotic cell that has already undergone primary endosymbiosis, resulting in organelles with more than two membranes.

Question 2

Which of the following protist groups is classified under the SAR supergroup and is responsible for causing malaria in humans?

Accepted Answer

Apicomplexans

Question 3

A scientist observes a unicellular organism with two nuclei and multiple flagella, living in an anaerobic environment. To which group does this organism most likely belong?

Accepted Answer

Diplomonads (Excavata)

Question 4

Which of the following best explains why brown algae are considered to have evolved through secondary endosymbiosis?

Accepted Answer

Their chloroplasts are surrounded by more than two membranes, indicating engulfment of a red alga by a heterotrophic eukaryote.

Question 5

Which of the following is NOT a characteristic shared by all protists?

Accepted Answer

They are all multicellular organisms.

Question 6

A patient is diagnosed with amoebic dysentery after drinking contaminated water. Which protist group is responsible for this disease?

Accepted Answer

Entamoeba (Amoebozoans, Unikonta)

Question 7

Which of the following correctly matches a protist group with its primary mode of nutrition?

Accepted Answer

Diatoms – photosynthetic autotrophs

Question 8

During the life cycle of Plasmodium (the malaria parasite), which stage is haploid?

Accepted Answer

Merozoite

Question 9

Which of the following statements about the cellular slime mold life cycle is correct?

Accepted Answer

Individual haploid amoebae aggregate to form a multicellular slug when food is scarce.

Question 10

Which of the following is the closest living relative of land plants?

Accepted Answer

Charophytes (a group of green algae)

Question 11

A marine biologist discovers a protist with a glass-like silica shell and chloroplasts. To which group does this organism most likely belong?

Accepted Answer

Diatoms (Stramenopiles, SAR)

Question 12

Which of the following supergroups contains both animals and fungi, as well as several protist groups?

Accepted Answer

Unikonta

Question 13

Which of the following best describes the difference between plasmodial and cellular slime molds?

Accepted Answer

Plasmodial slime molds form a large, multinucleate, diploid mass, while cellular slime molds exist as individual haploid cells that aggregate when food is scarce.

Question 14

Which of the following protist groups is characterized by the presence of a kinetoplast, a unique structure containing extranuclear DNA?

Accepted Answer

Kinetoplastids (Euglenozoans, Excavata)

Question 15

Which of the following is a key feature that distinguishes Euglenids from other protists?

Accepted Answer

They possess a unique crystalline rod inside their flagella.

Question 16

A harmful algal bloom in the ocean is observed to produce toxins that accumulate in shellfish, causing illness in humans. Which protist group is most likely responsible?

Accepted Answer

Dinoflagellates (Alveolates, SAR)

Question 17

Which of the following equations best represents the process of photosynthesis as carried out by green algae?

Accepted Answer

$$6\ \mathrm{CO}_2 + 6\ \mathrm{H}_2\mathrm{O} \rightarrow \mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6 + 6\ \mathrm{O}_2$$

Question 18

Which of the following protist groups is most likely to be found forming symbiotic relationships with corals, providing them with photosynthetic products?

Accepted Answer

Dinoflagellates (Alveolates, SAR)

Question 19

Which of the following best describes the diversity of protists?

Accepted Answer

Protists include unicellular, colonial, and multicellular organisms with a wide range of nutritional strategies and life cycles.

Question 20

Which of the following is a defining characteristic of the Archaeplastida supergroup?

Accepted Answer

They include red algae, green algae, and land plants, all of which have chloroplasts derived from primary endosymbiosis.

Protists: Diversity, Classification, and Evolutionary Relationships

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