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Questions and Answers
Which statements about dinoflagellates are true?
Which statements about dinoflagellates are true?
What is the primary characteristic of apicomplexans?
What is the primary characteristic of apicomplexans?
How do ciliates primarily reproduce?
How do ciliates primarily reproduce?
What distinguishes foraminifera (forams) from other protists?
What distinguishes foraminifera (forams) from other protists?
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Which feature is common among rhizarians?
Which feature is common among rhizarians?
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What are the skeletons of radiolarians primarily made from?
What are the skeletons of radiolarians primarily made from?
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What characteristic feature do all ciliates possess?
What characteristic feature do all ciliates possess?
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Which group includes both red algae and green algae?
Which group includes both red algae and green algae?
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What is the primary reason milk should undergo pasteurization?
What is the primary reason milk should undergo pasteurization?
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What is typically added to milk to accelerate curd formation during cheese production?
What is typically added to milk to accelerate curd formation during cheese production?
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Food intoxication is primarily caused by what type of substance?
Food intoxication is primarily caused by what type of substance?
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What does the virus-first hypothesis suggest about the origin of viruses?
What does the virus-first hypothesis suggest about the origin of viruses?
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Which of the following is NOT a major cause of food spoilage?
Which of the following is NOT a major cause of food spoilage?
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Which hypothesis suggests that viruses were once small cells parasitizing larger cells?
Which hypothesis suggests that viruses were once small cells parasitizing larger cells?
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Which category of foodborne illness involves live microbial cells targeting the intestine?
Which category of foodborne illness involves live microbial cells targeting the intestine?
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What is the primary structure of a virus that contains the genetic material?
What is the primary structure of a virus that contains the genetic material?
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What type of reactions can lead to food spoilage through enzymatic processes?
What type of reactions can lead to food spoilage through enzymatic processes?
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Which of the following is an example of bioterrorism?
Which of the following is an example of bioterrorism?
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What is the primary purpose of the primary stage in sewage treatment?
What is the primary purpose of the primary stage in sewage treatment?
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What distinguishes naked viruses from enveloped viruses?
What distinguishes naked viruses from enveloped viruses?
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Which of the following diseases is NOT linked to unsanitary sewage disposal?
Which of the following diseases is NOT linked to unsanitary sewage disposal?
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Which food spoilage factor can be categorized under physical causes?
Which food spoilage factor can be categorized under physical causes?
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What is the maximum diameter size of a typical megavirus?
What is the maximum diameter size of a typical megavirus?
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During the secondary stage of sewage treatment, what mainly occurs?
During the secondary stage of sewage treatment, what mainly occurs?
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What type of microscope is necessary to detect viruses due to their small size?
What type of microscope is necessary to detect viruses due to their small size?
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Which statement is true concerning the impacts of microbes on food?
Which statement is true concerning the impacts of microbes on food?
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What are the individual protein subunits that make up the viral capsid called?
What are the individual protein subunits that make up the viral capsid called?
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What occurs during the tertiary stage of sewage treatment?
What occurs during the tertiary stage of sewage treatment?
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Which hypothesis proposes that some viruses evolved from DNA or RNA escaping from larger organisms?
Which hypothesis proposes that some viruses evolved from DNA or RNA escaping from larger organisms?
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Which of the following is considered a beneficial effect of microbes in food?
Which of the following is considered a beneficial effect of microbes in food?
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What are bioremediators primarily used for in sewage treatment?
What are bioremediators primarily used for in sewage treatment?
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What is a neutral effect of microbes in food?
What is a neutral effect of microbes in food?
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What is the primary role of glomeromycetes in relation to plants?
What is the primary role of glomeromycetes in relation to plants?
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Which of the following accurately describes ascomycetes?
Which of the following accurately describes ascomycetes?
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What distinguishes basidiomycetes from other fungi?
What distinguishes basidiomycetes from other fungi?
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How do fungi contribute to the ecosystem?
How do fungi contribute to the ecosystem?
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What kind of relationships do fungi typically establish with other organisms?
What kind of relationships do fungi typically establish with other organisms?
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Which component of plant material is best decomposed by basidiomycetes?
Which component of plant material is best decomposed by basidiomycetes?
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How many species are estimated to belong to the Ascomycetes phylum?
How many species are estimated to belong to the Ascomycetes phylum?
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What is one of the main characteristics of the fruiting bodies formed by ascomycetes?
What is one of the main characteristics of the fruiting bodies formed by ascomycetes?
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What characteristic distinguishes coenocytic fungi from other fungi?
What characteristic distinguishes coenocytic fungi from other fungi?
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How do mycorrhizal fungi assist plants?
How do mycorrhizal fungi assist plants?
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What feature of fungal hyphae maximizes their feeding efficiency?
What feature of fungal hyphae maximizes their feeding efficiency?
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What type of mycorrhizal fungi forms sheaths of hyphae over the root surface?
What type of mycorrhizal fungi forms sheaths of hyphae over the root surface?
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Which reproductive method is not utilized by fungi?
Which reproductive method is not utilized by fungi?
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What initiates sexual reproduction in fungi?
What initiates sexual reproduction in fungi?
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What is a function of haustoria in certain fungi?
What is a function of haustoria in certain fungi?
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What describes the main structure formed by fungal hyphae?
What describes the main structure formed by fungal hyphae?
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Study Notes
Protists - Overview
- Eukaryotic organisms
- Possess a nucleus and a nuclear envelope
- Contain membrane-enclosed organelles
- Highly diverse, mostly unicellular, some multicellular
Protist Nutrition
- Some are photoautotrophs (contain chloroplasts)
- Others are chemoheterotrophs (absorb or ingest organic molecules)
- Mixotrophs combine photosynthesis and heterotrophic nutrition
Endosymbiosis
- Symbiotic relationship where one organism lives within another
- Scientists believe protists and other eukaryotes evolved from a host cell engulfing a bacterium
- Many protists exist by living within other organisms, a form of parasitism
Symbiotic Relationships with Protists
- Many protists are aquatic, found wherever water exists
- Some are mutualistic (e.g., in coral reefs)
- Some organisms depend on protists for food
- Photosynthetic protists are producers, organisms use light to convert CO2 to organic compounds
- Other organisms depend on them for food by eating either them directly or something that consumed them
- Some protists act as parasites (e.g., in intestines, in malaria)
Supergroups of Protists
- Excavata (diplomonads, parabasalids, euglenozoans)
- SAR (stramenopiles, alveolates, rhizarians)
- Archaeplastida (red algae, green algae)
- Unikonta (amoebozoans, opisthokonts)
Excavata
- Possess an "excavated" feeding groove
- Modified mitochondria (mitosomes) for anaerobic respiration
- Unique flagella for mobility and predation
- Includes diplomonads, parabasalids, and euglenozoans
Diplomonads
- Reduced mitochondria (mitosomes)
- Lack electron transport chains
- Obtain energy from anaerobic pathways
- Two equal nuclei and multiple flagella for rapid movement
- Mostly parasitic, one example is Giardia intestinalis causing intestinal infections in mammals.
Parabasalids
- Reduced mitochondria (hydrogenosomes)
- Generate anaerobic energy and release hydrogen gas
- Mostly parasitic, example is Trichomonas vaginalis (STD)
Euglenozoans
- Diverse forms (predatory heterotrophs, photosynthetic autotrophs, mixotrophs, parasites)
- Rod-shaped structure in flagella
- Often carried by disease vectors like the tsetse fly (Trypanosoma) causing sleeping sickness
SAR
- Stramenopiles, Alveolates, Rhizarians
- Diverse group with DNA similarities
- Stramenopiles (diatoms, golden algae, brown algae) often photosynthetic with hair-like projections on flagella
Diatoms
- Unicellular, photosynthetic algae
- Glass-like walls of silicon dioxide
- Photosynthetic activity affects CO2 levels
- Important as a food source for other organisms
Golden Algae
- Mostly unicellular
- Yellow-brown carotenoid pigments
- Biflagellated cells
Brown Algae
- Mostly multicellular, marine
- Brown or olive colors due to carotenoids
- Many "seaweeds" are brown algae and reproduce through "alternation of generations"
Alveolates
- Membrane-enclosed sacs ("alveoli") beneath plasma membrane
- Dinoflagellates, Apicomplexans, Ciliates
Dinoflagellates
- Two flagella in grooves
- Some are photosynthetic, others are heterotrophic or mixotrophic
- Some produce toxins that can cause harmful algal blooms
- Some are responsible for red tides
Apicomplexans
- Mostly parasitic
- Sporozoites (infectious cells)
- Asexual and sexual stages often require two or more host species
- Example: Plasmodium (malaria)
Rhizarians
- Amoebas that move and feed with pseudopodia
- Includes radiolarians and forams
Archaeplastida
- Red algae and green algae
- Red algae are often multicellular and use phycoerythrin, this pigment masks the chlorophyll and results in a red/pink color.
- Green algae, like land plants, are important photosynthesizers
Unikonta
- Closely related to fungi and animals
- Includes amoebozoans and opisthokonts\
- Amoebozoans (amoebas) use lobe-shaped pseudopodia
- Some amoebozoans are slime molds that have either plasmodial or cellular forms; this is their method of feeding and reproduction
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Description
This quiz explores the diverse world of protists, focusing on their classification, nutritional modes, and symbiotic relationships. Understand the distinctions between photoautotrophs, chemoheterotrophs, and mixotrophs, as well as the concept of endosymbiosis. Test your knowledge on the ecological roles that protists play in aquatic environments.
