Protists Overview
48 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the primary role of most plant pathogens that are fungi?

  • Enhance crop growth rate
  • Produce beneficial nutrients for crops
  • Increase resistance to pests
  • Cause tissue decay and death of the host (correct)

    • What major health issues are associated with the fungus Claviceps purpurea?

  • Convulsions and hallucinations (correct)
  • Nausea and fatigue
  • Diarrhea and dehydration
  • Allergic reactions and respiratory issues

    • Fungi from which genus are known to produce aflatoxins?

  • Claviceps
  • Botrytis
  • Fusarium
  • Aspergillus (correct)

    • Which of the following diseases is NOT caused by fungi?

    <p>Tetanus</p> Signup and view all the answers

    What is one of the consequences of harvests being tainted by aflatoxins?

    <p>Massive recalls of contaminated produce</p> Signup and view all the answers

    Which of the following fungi is referred to as 'noble rot'?

    <p>Botrytis cinerea</p> Signup and view all the answers

    How do fungi directly affect animals, including humans?

    <p>By colonizing and destroying tissues</p> Signup and view all the answers

    What is the significance of lysergic acid in relation to ergot?

    <p>It serves as a precursor to the drug LSD</p> Signup and view all the answers

    What term has been historically used to describe eukaryotic organisms that do not fit into the kingdoms Animalia, Fungi, or Plantae?

    <p>Protista</p> Signup and view all the answers

    Which of the following best describes a characteristic common to most protists?

    <p>They mostly inhabit aquatic environments.</p> Signup and view all the answers

    How are some protists being classified in recent years based on molecular genetics?

    <p>They are reassigned to kingdoms like Animalia, Plantae, or Fungi.</p> Signup and view all the answers

    What type of relationships do many protists participate in with other organisms?

    <p>Symbiotic relationships, often species-specific.</p> Signup and view all the answers

    Which of the following statements about protist cells is true?

    <p>Most protists are unicellular, but some are multicellular.</p> Signup and view all the answers

    What role do some protists play in the ecosystem related to decaying matter?

    <p>They contribute to the decay of dead organisms or their wastes.</p> Signup and view all the answers

    What explains the vast potential for undescribed protist diversity?

    <p>Many have symbiotic relationships that are species-specific.</p> Signup and view all the answers

    In what environments do protists typically thrive?

    <p>Aquatic environments, including freshwater and marine.</p> Signup and view all the answers

    What mechanism allows Trypanosoma brucei to evade the human immune system?

    <p>It alters its surface glycoproteins regularly.</p> Signup and view all the answers

    What is a consequence of untreated African sleeping sickness?

    <p>Irreversible damage to the nervous system.</p> Signup and view all the answers

    Which of the following statements about the prevalence of African sleeping sickness is true?

    <p>It has been reported at some of the lowest numbers in 50 years since 2009.</p> Signup and view all the answers

    What is the primary vector responsible for transmitting Trypanosoma cruzi, the causative agent of Chagas disease?

    <p>Blood-sucking bugs</p> Signup and view all the answers

    What is a serious health consequence related to chronic Chagas disease?

    <p>Heart failure caused by abnormal heart rhythms</p> Signup and view all the answers

    What role do glycoproteins play in the immune evasion by Trypanosoma brucei?

    <p>They are recognized as foreign by the immune system.</p> Signup and view all the answers

    How many people were estimated to be infected with Chagas disease in 2008?

    <p>10 million</p> Signup and view all the answers

    What outcome can occur due to the long-term effects of T.cruzi infections?

    <p>Malnutrition due to digestive system damage</p> Signup and view all the answers

    What characteristic is shared by all organisms within a supergroup?

    <p>They evolved from a single common ancestor.</p> Signup and view all the answers

    Which of the following diseases is primarily caused by the Plasmodium species?

    <p>Malaria</p> Signup and view all the answers

    Which of the following statements about Plasmodium falciparum is true?

    <p>It can destroy over half of a human's circulating blood cells.</p> Signup and view all the answers

    What role do mosquitoes play in the life cycle of Plasmodium species?

    <p>They act as a vector for transmitting the parasite to vertebrates.</p> Signup and view all the answers

    How does the immune system respond during a malaria infection caused by P.falciparum?

    <p>It mounts a massive inflammatory response.</p> Signup and view all the answers

    What is a significant consequence of the waste products released by Plasmodium during its life cycle?

    <p>They can induce delirium-inducing fever episodes.</p> Signup and view all the answers

    In which regions of the world is P.falciparum particularly concerning?

    <p>Tropical regions where the mosquito vectors thrive.</p> Signup and view all the answers

    What is a crucial technique in controlling malaria transmission?

    <p>Killing or avoiding exposure to Anopheles mosquitoes.</p> Signup and view all the answers

    What disease is caused by the oomycete Plasmopara viticola?

    <p>Downy mildew</p> Signup and view all the answers

    What significant historical event was precipitated by the potato late blight caused by Phytophthora infestans?

    <p>The Irish potato famine</p> Signup and view all the answers

    Which of the following statements about zooxanthellae is true?

    <p>They are a type of photosynthetic protist.</p> Signup and view all the answers

    What percentage of crops can be wiped out by late blight without pesticide application?

    <p>70%</p> Signup and view all the answers

    Why do reef-building corals not reside in waters deeper than 20 meters?

    <p>Not enough light for photosynthesis occurs at those depths.</p> Signup and view all the answers

    What is the result of a Plasmopara viticola infection in grape plants?

    <p>Stunted growth and discolored leaves</p> Signup and view all the answers

    Which ecological role do protists fulfill in the oceans?

    <p>They play significant roles as decomposers and producers.</p> Signup and view all the answers

    What is the primary effect of coral bleaching on corals?

    <p>Loss of algal pigments</p> Signup and view all the answers

    What is the primary role of fungi in ecosystems?

    <p>Decomposing organic matter to return nutrients to the soil</p> Signup and view all the answers

    Which division of fungi is characterized by the ability to reproduce without a sexual cycle?

    <p>Deuteromycota</p> Signup and view all the answers

    How do fungal exoenzymes aid in nutrient absorption?

    <p>They convert polysaccharides into glucose molecules.</p> Signup and view all the answers

    What is a potential application of fungi in environmental science?

    <p>Breaking down heavy metals and hydrocarbons</p> Signup and view all the answers

    Which of the following fungal divisions includes sac fungi?

    <p>Ascomycota</p> Signup and view all the answers

    What impact do many fungi have on other species?

    <p>They can be parasites or pathogens.</p> Signup and view all the answers

    What is one important factor that contributed to the classification of fungi into different divisions?

    <p>Their methods of sexual reproduction</p> Signup and view all the answers

    Which fungi division is associated with conjugated fungi?

    <p>Zygomycota</p> Signup and view all the answers

    Study Notes

    Protists

    • Eukaryotic organisms that didn't fit into Animalia, Fungi, or Plantae kingdoms historically
    • Single-celled eukaryotes that live in a variety of aquatic and terrestrial environments
    • Some are microscopic, unicellular
    • Some are large, multicellular species, like kelps
    • Modern molecular genetics shows some protists are more closely related to animals, plants, or fungi than to other protists
    • Protist lineages have been reassigned to different kingdoms due to close relationships found through molecular genetics
    • Protists display a great diversity in morphology, physiology, and ecology
    • Over 100,000 described species; exact number of undescribed species unknown
    • Many exist in symbiotic relationships with other organisms
    • Few characteristics common to all protists
    • Mostly aquatic (freshwater, marine, damp soil, snow)
    • Some are parasites infecting animals or plants
    • Some feed on dead organisms or waste, contributing to decay
    • Cells among the most complex of all cells
    • Many microscopic and unicellular
    • Some multicellular, form colonies, or multinucleated single cells with diverse morphologies
    • Sizes range from less than a micrometer to 3 meters
    • Cell membranes or cell walls
    • Glassy silica shells, or covered in pellicles of interlocking protein strips for flexible armor
    • Most are motile (flagella, cilia, pseudopodia)
    • Can move toward light by coupling locomotion with light-sensing organs
    • Can be aerobic or anaerobic
    • Photosynthetic protists (photoautotrophs) have chloroplasts to obtain energy
    • Heterotrophs consume organic materials
    • Obtain energy through phagocytosis (engulfing food particles)

    Protist Reproduction

    • Mostly asexual reproduction (binary fission, multiple fission, budding)
    • Sexual reproduction involving meiosis and fertilization common in some
    • New variations of progeny may result, better suited to surviving in changed environments
    • Sexual reproduction is often associated with periods of nutrient depletion or environmental change
    • Cysts are resting, protective stages that allow for survival during challenging conditions

    Protist Diversity

    • Relationships are better understood with DNA sequencing
    • Morphological similarities may be analogous, not recent common ancestry
    • Classification scheme groups eukaryotes into six supergroups (Excavata, Chromalveolata, Rhizaria, Archaeplastida, Amoebozoa, and Opisthokonta)
    • Monophyletic nature is supported by evolutionary traits and genetic analysis

    Human Pathogens

    • Many protists are pathogenic parasites (malaria, African sleeping sickness, waterborne gastroenteritis)
    • Infect other organisms to survive
    • Some parasitic species prey on plants, effecting massive destruction of food crops
    • Plasmodium species (specifically P.falciparum) are the primary causative agents of malaria and lead to high mortality rates, particularly in African children

    Trypanosomes

    • Parasites cause African sleeping sickness ( T. brucei)
    • Evade immune systems by changing surface glycoproteins during each infectious cycle
    • Symptoms affect the nervous system
    • T. cruzi is another species causing Chagas disease (Latin America), affecting heart and digestive systems

    Plant Parasites

    • Some protists (oomycetes) are plant parasites destroying crops (downy mildew on grape vines [ Plasmopara viticola], late blight of potato [ Phytophthora infestans])
    • Result in significant crop losses and famines

    Protists as Food Sources

    • Essential sources of nutrition for other organisms
    • Some consumed directly in form of plankton
    • Others (e.g., photosynthetic protists) are producers providing nutrition for other organisms in food webs

    Protist Importance

    • Essential primary producers in aquatic environments
    • Contribute to carbon fixation and food webs
    • Crucial decomposition agents (saprobes/saprophytes, feed on dead organisms)
    • Play a vital role in nutrient cycling

    Fungi

    • Eukaryotic organism
    • Diverse group of organisms
    • Mostly multicellular (Some yeasts are unicellular)
    • Cell walls contain complex polysaccharides (chitin and glucan), not cellulose
    • Membrane-bound nucleus
    • Non-photosynthetic
    • Heterotrophic (absorb nutrients)
    • Complex cellular organization
    • Can be asexual or sexual reproduction
    • Fungi produce spores for dispersal
    • Important decomposers increasing nutrient availability
    • Play roles in mutualistic symbiotic relationships, such as mycorrhizae with plant roots, plant parasitism, and lichens
    • Some are pathogenic, causing diseases in plants and animals
    • Commercial enzymes and antibiotics can be produced
    • Important in food and beverages(e.g. fermentation of grains produce beer, and fruits to wine)
    • Involved in ecological roles and cycles

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    Protists: Chapter 13b PDF

    Description

    Explore the fascinating world of protists, which are eukaryotic organisms that do not fit into the traditional Animalia, Fungi, or Plantae kingdoms. This quiz covers their diverse environments, relationships, and complexities, highlighting their ecological roles as parasites, symbionts, and decomposers.

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser