Question 1

Which statement best describes why protists are considered a paraphyletic group?

Accepted Answer

They do not include all descendants of a single common ancestor.

Question 2

Which of the following is a primary ecological role of phytoplankton protists?

Accepted Answer

Primary production at the base of aquatic food webs.

Question 3

A scientist observes a protist with a ventral feeding groove and modified mitochondria called mitosomes. Which group does this organism most likely belong to?

Accepted Answer

Excavata

Question 4

Which feature distinguishes Rhizaria from other protist groups?

Accepted Answer

Long, slender pseudopodia used for movement and feeding.

Question 5

Which protist group is characterized by the presence of alveoli under the plasma membrane?

Accepted Answer

Alveolata

Question 6

Brown algae are classified as multicellular protists. Which pigment is primarily responsible for their photosynthetic activity?

Accepted Answer

Fucoxanthin

Question 7

Which of the following best explains why diatomaceous earth is used in products like pesticides and absorbents?

Accepted Answer

It is made of silica shells that provide abrasive and absorbent properties.

Question 8

A protist is observed to have two flagella and is photosynthetic. To which group does it most likely belong?

Accepted Answer

Excavata (Euglenids)

Question 9

Which of the following protists is responsible for the destruction of potato crops due to its filamentous, fungus-like nature?

Accepted Answer

Oomycetes (Phytophthora infestans)

Question 10

A patient is diagnosed with a parasitic infection in the small intestine caused by Giardia. Which cellular feature is most likely observed in this organism?

Accepted Answer

Lost or modified mitochondria

Question 11

Which of the following statements about protist flagella is correct?

Accepted Answer

Some protists have one or no flagella, while others have two.

Question 12

Which process do amoebozoans use to obtain food?

Accepted Answer

Engulfing prey by phagocytosis

Question 13

Which protist group includes organisms with shells made of CaCO$_3$ and reticulopodia?

Accepted Answer

Rhizaria (Foraminifera)

Question 14

Which of the following is a correct application of molecular phylogenies in protist classification?

Accepted Answer

Using DNA sequences to construct phylogenetic trees and clarify evolutionary relationships.

Question 15

Which protist group is most likely to include photosynthetic organisms with flagella covered in hair-like projections?

Accepted Answer

Stramenopiles

Question 16

Which of the following is a real-world consequence of protist activity in ecosystems?

Accepted Answer

Protists can increase ecosystem productivity and affect human health.

Question 17

Which protist group is most likely to be studied using light microscopy due to their small size and diverse cell structures?

Accepted Answer

Protists

Question 18

Which of the following is a product derived from brown algae and used as a thickener in foods like ice cream and pudding?

Accepted Answer

Alginate

Question 19

A protist is observed to have a shell made of silica and is used in the production of absorbents and pesticides. Which organism is this most likely to be?

Accepted Answer

Diatom

Question 20

Which of the following best describes the evolutionary significance of protists?

Accepted Answer

They are the earliest eukaryotes and have a major impact on ecosystem productivity.

Protists: Diversity, Classification, and Biological Importance

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