Chapter 28 Quiz; Protists

Which organisms are capable of producing a "red tide"? - Dinoflagellates - None of the listed responses is correct. - Euglenids - Sporozoans - Chrysophytes (diatoms)

Dinoflagellates

Which example below is a characteristic shared by diplomonads and parabasalids? - Both lack plastids. - Both have two nuclei. - Both have a single flagellum. - Both lack mitochondria. - Both are adapted to aerobic environments.

Both lack plastids.

Which of the following is not a protist genera that parasitizes humans? - Chlamydomonas - All of the listed genera consist of human parasites. - Entamoeba - Trichomonas - Plasmodium

Chlamydomonas

Which of these groups includes photosynthetic unicellular organisms with flagella and contractile vacuoles? - Euglenids - Apicomplexans - Ciliates - Dinoflagellates - Diatoms

Euglenids

Which of the following is one of the main weaknesses of the proposed classification scheme in which all eukaryotes are divided into four supergroups? - It shows all four supergroups diverging simultaneously from a common ancestor. - It postulates that photosynthetic protists arose by way of endosymbiosis. - It does not explain the extra membranes found in some plastids. - It does not take into account the importance of endosymbiosis. - It does not account for "amitochondriate" protists.

It shows all four supergroups diverging simultaneously from a common ancestor.

Which of the following is the best description of protists' contribution to photosynthesis? - About 30% of the world's photosynthesis is performed by protists. - The net effect of protists is to impede photosynthesis by parasitizing plants. - Only terrestrial protists substantially contribute to photosynthesis. - Protists carry out the majority of the world's photosynthesis. - Protists play an important role only through symbioses with photosynthetic organisms.

About 30% of the world's photosynthesis is performed by protists.

Which of the following is not a group included in the protists? - All of the listed groups are protists. - Forams - Diatoms - Brown algae - Ciliates

All of the listed groups are protists.

Which of the following is not a structure used for locomotion in protists? - All of the listed structures are used for locomotion in protists. - Undulating membrane - Pseudopodia - Flagella - Cilia

All of the listed structures are used for locomotion in protists.

What do a carnivorous dinoflagellate, a parasitic apicomplexan, and a ciliate have in common?

All three have sacs known as alveoli just beneath their plasma membranes.

Which of these groups includes parasitic unicellular organisms with a complex of organelles specialized for penetrating host cells and tissues? - Apicomplexans - Ciliates - Euglenoids - Dinoflagellates - Diatoms

Apicomplexans

Which protist group is thought to be most closely related to animals? - Choanoflagellates - Alveolates - Stramenopiles - Euglenozoans - Diplomonads

Choanoflagellates

Which of these groups is characterized by cells that have more than one nucleus? - Ciliates - Apicomplexans - Euglenids - Dinoflagellates - Diatoms

Ciliates

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? - Diatoms - Apicomplexans - Ciliates - Euglenids - Dinoflagellates

Diatoms

Which of these groups includes species that produce a substance that is toxic to humans? - Dinoflagellates - Apicomplexans - Ciliates - Euglenids - Diatoms

Dinoflagellates

Protists are best described as which of the following? - Eukaryotes that are not plants, animals, or fungi - Single-celled organisms that are not bacteria - The domain containing the greatest range of unicellular structures and metabolisms - Simple eukaryotes lacking a well-developed cytoskeleton - The most diverse group of prokaryotic organisms

Eukaryotes that are not plants, animals, or fungi

Parasites of the genus Trypanosoma evade immune responses through what defense? - Frequently changing their surface proteins - Causing little damage to the host - Infecting cells of the immune system - Forming dormant endospores - Remaining on the outside of the host

Frequently changing their surface proteins

Why have protists been "mixed in" with plants, animals, and fungi under the hypothesis that groups eukaryotes into five supergroups?

Many protists are more closely related to plants, animals, or fungi than they are to each other and recent evidence makes it clear that the former kingdom Protista was paraphyletic.

Which protists were once categorized as fungi due to their multinucleate filaments that resemble hyphae? - Oomycetes - Parabasalids - Golden algae - Stramenopiles - Dinoflagellates

Oomycetes

__________ is a protist that causes late blight of potatoes and was responsible for the Irish potato famine of the 19th century.

Phytophthora infestans

Which of the following does not take place during the process of conjugation? - Reproduction - Exchange of genetic material - Cell fusion - Mitosis - Meiosis

Reproduction

Which of the following is not a cellular organelle possessed by a protist? - Sporozoite - Mitochondria - Plastid - Hydrogenosome - Mitosome

Sporozoite

What is one way in which a cellular slime mold differs from a plasmodial slime mold?

What is one way in which a cellular slime mold differs from a plasmodial slime mold?

The holdfast of brown algae functions in __________.

anchoring the algae

Green algae are divided into two main groups, the charophytes and the __________.

chlorophytes

The term mixotroph indicates that a protist __________.

combines photosynthesis and heterotrophic nutrition

Molecular data suggest that plastids originated as __________ engulfed by a heterotrophic eukaryote.

cyanobacteria

Although controversial, chromalveolates are proposed as a clade whose common ancestor __________.

engulfed a photosynthetic red alga in a secondary endosymbiosis event

Organisms are classified as Excavata based on __________.

morphological studies of the cytoskeleton

The term algae refers to __________.

several diverse groups of photosynthetic protists

Apicomplexans are currently assigned to the chromalveolates because __________.

the apicoplast, a modified plastid, appears to be of red algal origin