Questions and Answers
What is the total estimated number of extant (living) protozoan species?
Which group of protozoa has no free-living species?
Which structure covers the cytoplasm of protozoa?
What type of organisms do the majority of free-living protozoan species inhabit?
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What is the main characteristic of protozoa regarding their cellular structure?
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How many species of flagellates are estimated to be parasitic?
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What crucial life activities do protozoa and higher metazoan eukaryotes share?
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In which kingdom are protozoa classified?
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What is the primary function of the pseudopodia in foraminiferans?
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Which material is primarily used to construct the tests of foraminiferans?
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What type of locomotion mechanism is used by zooflagellates?
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What adaptation assists Euglena in orienting itself to light?
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In which environment are Euglena primarily found?
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Which reproduction method is most commonly observed in zooflagellates?
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What type of nutrition does Euglena utilize when kept in the dark?
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What constitutes the cell wall of Volvox?
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What is the primary function of the pellicle in protozoa?
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Which component of protozoan cytoplasm is responsible for containing organelles?
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Which method describes the ingestion of fluid nutrients in protozoa?
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What is a distinct feature of the Apicomplexa group of protozoa?
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Which type of nutrition do all protozoa exhibit?
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What is the most common method of asexual reproduction in protozoa?
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What structure in protozoa helps with osmoregulation?
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Which process is NOT a characteristic of protozoan nutrition?
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What was the estimated number of malaria cases worldwide in 2016?
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What was the reported number of deaths due to malaria in 2016?
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Which species of malaria does not cause relapse?
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How long can the prepatent period last for Plasmodium falciparum?
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For which species of malaria can periodic relapse occur over several years?
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What is the estimated range of years for relapse with Plasmodium vivax?
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What is one of the major factors contributing to the geographic distribution of malaria?
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Which of the following is a common symptom of malaria during the prepatent period?
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What is the primary vector for Leucocytozoon parasites?
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Which organisms cause Equine Piroplasmosis?
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What type of organism is characterized by spores with several cells configured into valveless shells?
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What is the disease caused by Myxobolus pfeifferi primarily associated with?
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What is a characteristic of Microsporidia?
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Which organism is known to cause pébrine, affecting silkworm larvae?
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What disease does Nosema apis commonly cause in honey bees?
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What is a significant consequence of Myxobolus cerebralis infection in salmonids?
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Study Notes
Protozoa Overview
- Protozoa are a subkingdom of the kingdom Protista, comprising around 32,000 living species, with estimates exceeding 50,000, plus 34,000 extinct species.
- Approximately 21,000 species are free-living in various environments, while 11,000 are parasitic in vertebrate and invertebrate hosts.
- Classification includes around 6,900 flagellates, 11,550 amoebae, 7,200 ciliates, and 5,600 sporozoans.
Structure of Protozoa
- Protozoa are unicellular eukaryotes, with a membrane-enclosed nucleus and complex organelles.
- Microscopic in size, few are visible without magnification.
- Cytoplasm is differentiated into ectoplasm (outer layer) and endoplasm (inner layer), crucial for movement and feeding.
- Some protozoa possess a cytosome for fluid and particle ingestion; contractile vacuoles aid in osmoregulation.
- Specialized structures include Golgi apparatus, mitochondria, and lysosomes.
Nutrition Types
- Nutritional modes in protozoa include holozoic (organic materials), with methods like phagocytosis (engulfing particles), pinocytosis (engulfing fluids), and autotrophic or heterotrophic pathways depending on conditions.
- Nutrition strategies vary from photosynthesis in light to saprozoic absorption in the dark.
Reproduction
- Protozoan reproduction can be asexual or sexual; the most common asexual method is binary fission.
- Some species may develop protective tests or shells for structural integrity.
Major Protozoan Groups
- Foraminifera: Ancient, shelled organisms found mostly in oceans. Have chambered tests, utilize slender pseudopodia for feeding.
- Mastigophora: Unicellular zooflagellates that can be free-living or parasitic, equipped with flagella for movement; binary fission is common.
Examples of Subgroups
- Phytomastigina (Euglenoids): Found in freshwater, euglenoids like Euglena can switch from autotrophic to saprozoic nutrients based on light availability.
- Class Volvocaceae: Includes colonial forms such as Volvox, with a cellulose cell wall and flagella.
Parasitic Protozoa and Diseases
- Malaria caused by Plasmodium species, with significant global health impact, including 216 million cases and 445,000 deaths estimated in 2016.
- Relapses occur with P. ovale and P. vivax due to prolonged liver stages; P. falciparum can have lengthy prepatent periods.
- Leucocytozoon: Blood parasite affecting birds transmitted by simuliid and Culicoides flies.
- Piroplasmosis: Disease from Babesia species, primarily affecting horses and transmitted by ticks.
Microsporidia
- Eukaryotic unicellular organisms, obligate intracellular parasites that can affect both vertebrates and invertebrates.
- Importance in fisheries and veterinary medicine, exemplified by Nosema bombycis, which affects silkworms, and Nosema apis, affecting honey bees and causing nosemosis.
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Description
This quiz explores the diverse world of protozoa, covering their classification, structure, and nutritional modes. Learn about the different types of protozoa and their unique cellular characteristics. Test your knowledge on this fascinating subkingdom of Protista.
