Microbiology Chapter 12 Flashcards

Questions and Answers

What 3 characteristics define protozoa?

eukaryotic, unicellular, lack a cell wall

Protozoa are critical members of the ______ which are free-living, drifting organisms that form the basis of aquatic food chains.

plankton

Some ________ have 2 nuclei: macronuclei and micronuclei.

ciliates

Which nucleus controls metabolism?

macronucleus Signup and view all the answers

Which nucleus controls genetic recombination?

micronucleus Signup and view all the answers

Which nucleus controls sexual reproduction?

macro and micronuclei Signup and view all the answers

Which nucleus controls growth?

macronucleus Signup and view all the answers

All free-living aquatic and pathogenic protozoa exist as a motile feeding stage called a __________.

trophozoite Signup and view all the answers

Many protozoa have a hardy resting stage called a _________.

cyst Signup and view all the answers

What is a cyst characterized by?

thick capsule and low metabolic rate Signup and view all the answers

Most protozoa are ______otrophic.

Chemoheter Signup and view all the answers

Most protozoa reproduce asexually only, by or .

binary fission or schizogony Signup and view all the answers

Gametes fuse with one another to form a diploid _________.

zygote Signup and view all the answers

Paramecium reproduce sexually via a complex process called _________.

conjugation Signup and view all the answers

Parabasalids have mitochondria.

False Signup and view all the answers

________ is a parabasalid that has numerous flagella, inhabits the guts of termites, where it assists in the digestion of wood.

Trichonympha Signup and view all the answers

_________ is a parabasalid that proliferates and causes severe inflammation that can lead to sterility when the normally acidic pH of the vagina is raised.

Trichomonas Signup and view all the answers

What 3 groups are alveolates divided into?

ciliates, apicomplexans, and dinoflagellates Signup and view all the answers

________ is a ciliate that has apical cilia which create a whirlpool-like current to direct food into its mouth.

Vorticella Signup and view all the answers

_________ is a ciliate that is the only ciliate pathogenic to humans.

Balantidium Signup and view all the answers

________ is a ciliate that phagocytizes other protozoa.

Didinum Signup and view all the answers

Plasmodium is an apicomplexan that causes __________.

malaria Signup and view all the answers

________ is an apicomplexan that causes cryptosporidiosis.

Cryptosporidium Signup and view all the answers

_________ is an apicomplexan that causes toxoplasmosis.

Toxoplasma Signup and view all the answers

Which group of alveolates are bioluminescent?

dinoflagellates Signup and view all the answers

Which of the 3 groups of alveolates contain red pigment that causes the phenomenon called red tide?

dinoflagellates Signup and view all the answers

_ and __ are dinoflagellates that produce neurotoxins.

Gymnodium and Gonyaulax Signup and view all the answers

Which dinoflagellate causes memory loss, confusion, headaches, respiratory difficulties, skin rash, muscle cramps, and nausea? Such poisoning is called what?

Pfiesteria, (PEAS- possible estuary-associated syndrome) Signup and view all the answers

What are the 3 groups that scientists classify amoebae in?

Cercozoa, radiolaria, amoebozoa Signup and view all the answers

Which two groups of amoebae have threadlike pseudopodia?

Cercozoa and Radiolaria Signup and view all the answers

A major taxon of cercozoa is ___________. They have a porous shell composed of calcium carbonate.

foraminifera Signup and view all the answers

Which group of amoebae have ornate shells composed of silica and reinforce their pseudopodia with stiff internal bundles of microtubules?

Radiolaria Signup and view all the answers

Which group of amoebae are distinguished from the other 2 by having lobe-shaped pseudopodia and no shells?

Amoebozoa Signup and view all the answers

_ and _ can cause diseases of the eyes or brains of humans and animals that swim in water containing them.

Naegleria and Acanthamoeba Signup and view all the answers

Naegleria and Acanthamoeba are types of amoebae that belong to which group?

Amoebozoa Signup and view all the answers

________ are in the group amoebozoa and always live inside animals where they produce potentially fatal amebic dysentery.

Entamoeba Signup and view all the answers

What are the two types of slime molds?

Plasmodial slime molds and cellular slime molds Signup and view all the answers

What are 2 main ways that slime molds differ from fungi?

they lack cell walls and they are phagocytic rather than absorptive in their nutrition Signup and view all the answers

Which type of slime mold exists as streaming, coenocytic, colorful filaments of cytoplasm that creep as amoebae through forest litter, feeding by phagocytizing organic debris and bacteria?

plasmodial (acellular) slime molds Signup and view all the answers

Which type of slime mold exists as individual haploid myxamoebae that phagocytize bacteria, yeasts, dung, and decaying vegetation?

cellular slime molds Signup and view all the answers

Which type of slime mold produces spores as a result of meiosis?

Plasmodial slime molds Signup and view all the answers

Which type of slime mold produces spores but they are not enclosed in a common wall and they are not the result of meiosis?

cellular slime molds Signup and view all the answers

The Euglenozoa include and _.

Euglenids and kinetoplastids Signup and view all the answers

Euglenozoa have mitochondria.

True Signup and view all the answers

Euglenids are ________trophic.

Photoauto Signup and view all the answers

Euglenids store food as a unique polysaccharide called _________ instead of starch.

paramylon Signup and view all the answers

Euglenids move by using their flagella as well as by flowing, contracting, and expanding their cytoplasm. This is called ______________.

Euglenoid movement Signup and view all the answers

Each euglenid has a __________ that plays a role in positive phototaxis by casting a shadow on a photoreceptor at the flagellar base, triggering movement in that direction.

red eyespot Signup and view all the answers

Euglenids reproduce how?

mitosis followed by cytokinesis Signup and view all the answers

Euglenids form ______ when exposed to harsh conditions.

cysts Signup and view all the answers

Kinetoplastids have a single large mitochondrion that contains a unique region of mitochondrial DNA called a __________.

kinetoplast Signup and view all the answers

Diplomonadida have mitochondria.

False Signup and view all the answers

Diplomonadida have __________ in the cytoplasm and mitochondrial genes in the nuclear chromosomes.

mitosomes Signup and view all the answers

What are the seven groups of protozoa?

Parabasala, Alveolata, Cercozoa, Radiolaria, Amoebozoa, Euglenozoa, and Diplomonadida Signup and view all the answers

Fungi include _, , and ______.

yeasts, molds, mushrooms Signup and view all the answers

How do fungi differ from protozoa?

they have cell walls Signup and view all the answers

What are the cell walls of fungi made up of?

chitin Signup and view all the answers

How do fungi differ from plants?

They lack chlorophyll and do not perform photosynthesis Signup and view all the answers

Fungi are ______trophic.

chemohetero Signup and view all the answers

Mycology is the study of ________.

fungi Signup and view all the answers

The vegetative (nonreproductive) body of a fungus is called its ________.

thallus Signup and view all the answers

Thalli of __________ are large.

molds Signup and view all the answers

Thalli of ________ are small.

yeasts Signup and view all the answers

Thalli of ________ are composed of filaments called hyphae.

molds Signup and view all the answers

Hyphae are either or .

septate or aseptate Signup and view all the answers

________ hyphae are multinucleate.

Aseptate Signup and view all the answers

Fungi that produce 2 types of thalli are said to be ________.

dimorphic Signup and view all the answers

What are 2 examples of dimorphic fungi?

Histoplasma capsulatum and Coccidioids immitis Signup and view all the answers

Hyphae intertwined to form a tangled mass is called what?

mycelium Signup and view all the answers

The genus _________ contains the largest known organisms on Earth.

Armillaria Signup and view all the answers

Most fungi are _______ —they absorb nutrients from the remnants of dead organisms.

saprobes Signup and view all the answers

Fungi that derive their nutrients from living plants and animals usually have modified hyphae called __________ which penetrate the tissue of the host to withdraw nutrients.

haustoria Signup and view all the answers

In sexual spore formation of fungi, haploid (n) cells from a + thallus and a - thallus fuse to form ________.

dikaryon Signup and view all the answers

What are the four major subgroups of fungi?

zygomycota, ascomycota, basidiomycota, and deuteromycetes Signup and view all the answers

How do organisms in zygomycota reproduce?

asexually via sporangiospores Signup and view all the answers

________ is a division of Zygomycota and the organisms within it are obligatory intracellular parasites that spread from host to host as small, resistant spores.

Microsporidia Signup and view all the answers

Ascomycota is characterized by the formation of haploid ____ within sacs called _.

ascospores, asci Signup and view all the answers

How do ascomycota organisms reproduce?

conidiospores Signup and view all the answers

Most of the fungi that spoil food are __________.

Ascomycetes Signup and view all the answers

Mushrooms and other fruiting bodies of basidiomycetes are called _______.

basidiocarps Signup and view all the answers

Cryptococcus neoformans comes from the division of fungi and is the leading cause of ____.

Basidiomycota, fungal meningitis Signup and view all the answers

Which division of fungi has sexual stages that are unknown?

Deuteromycetes Signup and view all the answers

Partnerships between fungi and photosynthetic microbes—commonly, cyanobacteria, or less frequently, green algae

Lichens Signup and view all the answers

What are the 3 basic shapes of lichens?

Fruticose, Crustose, and Foliose Signup and view all the answers

Study Notes

Characteristics of Protozoa

Protozoa are defined as eukaryotic, unicellular organisms that lack a cell wall.
They play a crucial role in aquatic ecosystems as plankton, serving as a foundation for food chains.

Nuclei in Ciliates

Ciliates possess two types of nuclei: macronuclei, which manage metabolism and growth, and micronuclei, which control genetic recombination and sexual reproduction.

Stages of Protozoan Life Cycle

Free-living protozoa exist as trophozoites, a motile feeding stage.
Many protozoa can form cysts, a hardy resting stage characterized by a thick capsule and low metabolic activity.

Reproduction in Protozoa

Most protozoa reproduce asexually through binary fission or schizogony.
Sexual reproduction involves gamete fusion, forming a diploid zygote, with some protozoa, like Paramecium, employing conjugation.

Parabasalids

Parabasalids, like Trichonympha and Trichomonas, lack mitochondria.
Trichonympha aids digestion in termites, while Trichomonas can cause severe inflammation and infertility.

Alveolates Groups

Alveolates are categorized into ciliates, apicomplexans, and dinoflagellates.
Specific ciliates include Vorticella, Balantidium (only ciliate pathogenic to humans), and Didinium, which preys on other protozoa.

Apicomplexans

Plasmodium causes malaria, Cryptosporidium induces cryptosporidiosis, and Toxoplasma is responsible for toxoplasmosis.

Dinoflagellates

This group is characterized by bioluminescence and can cause red tides due to red pigment.
Gymnodium and Gonyaulax produce neurotoxins, while Pfiesteria can lead to various neurological symptoms.

Amoebae Classification

Amoebae are classified into Cercozoa, Radiolaria, and Amoebozoa, with Cercozoa and Radiolaria featuring threadlike pseudopodia.

Slime Molds

Two main types of slime molds are plasmodial (acellular) and cellular, differing in structure and reproductive mechanisms.
Plasmodial slime molds are streaming coenocytic organisms, while cellular slime molds consist of individual myxamoebae.

Euglenozoa and Their Characteristics

Euglenozoa include Euglenids, which are photoautotrophic and store food as paramylon, and Kinetoplastids, featuring a unique mitochondrial structure known as a kinetoplast.

Fungal Characteristics

Fungi differ from protozoa by having chitin as their cell wall component and being chemoheterotrophic.
The vegetative body (thallus) of fungi can vary in size and structure, with molds being composed of filaments called hyphae.

Fungal Reproduction

Fungi reproduce via sexual (dikaryon formation) and asexual means (e.g., sporangiospores).
Major fungal subgroups include Zygomycota, Ascomycota, Basidiomycota, and Deuteromycetes.

Unique Fungi

Microsporidia are obligate intracellular parasites within Zygomycota.
Ascomycota produce ascospores in sacs called asci and reproduce primarily through conidiospores.

Lichens

Lichens represent a symbiosis between fungi and photosynthetic microbes like cyanobacteria or green algae, existing in three basic shapes: fruticose, crustose, and foliose.

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Test your knowledge on Chapter 12 of Microbiology with these flashcards. This quiz covers essential characteristics of protozoa, their role in aquatic ecosystems, and their unique cellular structures. Perfect for students looking to reinforce their understanding of this chapter.