MICRO 212: Chapters 21-25

Review major characteristics of the Staphylococci that help distinguish the genus by completing each sentence.

Staphylococci are normally associated with human skin and mucous membranes. For this reason, they are often associated with boils and wound infections. Certain strains are particularly concerning because they are resistant to multiple antibiotics. These strains have become such dangerous pathogens by acquiring virulence factors. Finally, one must note that Staphylococci cause widespread food poisoning as well.

Match the structures with their functions.

Stigma - helps the organism orient to light Pyrenoid - associated with the synthesis and storage of starch Contractile Vacuole - maintain water regulation

Classify the following attributes as belonging to either streptococci or enterococci.

Streptococci - Found in the mouth and respiratory tract, Can form biofilms, Either alpha or beta hemolytic, Possess M protein in cell wall Enteroococci - Found in the GI tract, Does not usually form biofilms, Can be alpha or beta hemolytic abilities, Lack M protein in cell wall

The order Lactobacillales produce lactic acid as their major or sole fermentation product and are sometimes collectively called lactic acid bacteria (LAB). Pick the organisms below that are considered to be LAB.

Streptococcus, Enterococcus, Lactococcus, Lactobacillus, and Leuconostoc

Review major characteristics of Streptomycetes by completing each sentence.

Streptomyces found in soils play an important role in mineralization of recalcitrant organic materials and produce volatile geosmin that gives soil an earthy smell. Beyond these ecological roles, Streptomyces are famous for synthesizing a wide range of antibiotics. The large genus Streptomyces are strict aerobes These aerial structures form chains of nonmotile spores. Streptomycetes are common bacteria in the environment that form aerial hyphae.

Complete each sentence about the Gram-negative photosynthetic bacteria.

The cyanobacteria use oxygenic phototrophy, unlike other Gram-negative photosynthetic bacteria. The green nonsulfur bacteria are usually photoheterophic The purple nonsulfur bacteria contain bacteriochlorophyll a or b. Green and purple sulfur bacteria, as well as cyanobacteria, are usually photolithoautotrophs. The purple nonsulfur bacteria are usually anaerobic photoorganoheterotrophs

Fill in the blank for each sentence that describes the discovery of the class Negativicutes.

The establishment of the class Negativicutes began with the isolation of bacteria from human skin. These isolates were found to possess an outer membrane, suggesting they are Gram-negative. However, when the nucleotide sequences of 16S rRNA genes were analyzed, it was determined the isolates were more closely related to Gram-positive bacteria The establishment of the class Negativicutes suggests that as more bacteria are isolated from nature, current taxonomic assignments may sometimes be changed to account for new information.

As a scientist working in a laboratory, you isolate an actinobacteria that appears to be Frankia. What characteristics would you look for in order to confirm the identification?

The presence of multilocular sporangia The preference for a microaerophilic environment The ability to grow at a pH as low as 1 A symbiotic association with alder tree roots The presence of the nitrogenase enzyme The production of the antibiotic vancomycin

If the micronucleus of a Paramecium protist were removed or silenced, the microbe would be able to continue its metabolic functions but would not be able to undergo conjugation.

True

You have recently isolated a Gram-positive bacterium from soil. When you view the microbe using a microscope, you note a palisade cellular arrangement suggesting snapping division. You therefore ask a colleague to help you figure out the easiest way to determine if the soil isolate belongs to the genus Arthrobacter or Corynebacterium. Which of the following would be the best response your colleague could offer?

Try growing the isolate in liquid and examine cell morphology during lag, exponential, and stationary phase.

Which organism causes African Sleeping Sickness?

Trypanosoma gambiense

Which organism group could be found in almost any environment where they will remain moist? (This includes glacial meltwater, marine environments, tide pools, lakes, and streams. Free-living forms are known to dwell in ventilation ducts and cooling towers, where they feed on microbial biofilms.)

Tubulinea

How many heterokont flagella are found extending from stramenopiles?

Two

Which of the following best describes the different morphologies of Chloroplastida?

Unicellular, colonial, filamentous, sheetlike, and tubular

What is the name of the distinctive structure used for food ingestion found in paramecia?

Vacuole

Important anaerobic, chemoheterotrophic cocci (usually in the diplococci form) that are parasites of homeothermic (warm-blooded) animals and inhabit the human tongue belong to the genus _______.

Veillonella

Bifidobacterium is used _________.

as a probiotic

Gardnerella is believed to be a bacterial agent of the human disease _________.

bacterial vaginitis

In humans, Ureaplasma urealyticum and Mycoplasma hominis are _________.

common parasitic microorganisms of the genital tract, and their transmission is related to sexual activity

Rank the order of events to describe the passage of food through some phagocytic protozoans. Begin by completing this sentence: food enters the (#1). End by completing this sentence: waste products exit the cell via the (#4). You must decide what goes at #2 and #3.

cytostome: 1 phagocytic vacuole becomes acidic: 2 phagocytic vacuole generates blebs: 3 cytoproct: 4

Oil companies are interested in the ________ test to date strata to the Early Cambrian period (~543 million years ago).

foram

Protist contractile vacuoles are used to _________.

maintain osmotic balance within the cell

Actinoplanete spores are unusual because in some species they are _________.

motile by flagella

Dictyostelium discoideum can form a large cellular mass called a __________.

pseudoplasmodium

Select the following statements that accurately describe actinobacterial exospores. (Check all that apply.)

Actinobacterial exospores are often formed above the substrate surface so they are more easily dispersed. Actinobacterial exospores are often formed by the differentiation of aerial hyphae.

Drag the descriptions to their corresponding bacterial type in order to test your knowledge of the Actinobacteria.

Actinomyces - Oral cavity is preferred habitat Arthrobacter - Soil organisms with snapping division Nocardia - Vegetative hyphae found in soils Corynebacterium - Forms metachromic granules Mycobacterium - Cell walls contain mycolic acids: Frankia - Symbiotic nitrogen-fixers: Propionibacterium - Swiss cheese fermentation Streptomyces - Synthesize an array of antibiotics

Which characteristic describes the morphology of Rhizaria?

Amoeboid

Fill in the blank to complete the following paragraph describing the structure and function of pseudopodia

Amoebozoa such as Myxogastria use lobopodia to engulf food particles. This feeding strategy is well suited digesting organic matter, which Myxogastria degrades through the release of hydrolytic enzymes as it glides over substrates. Rhizaria such as radiolarians use filopodia to capture food, while formaminifera use reticulopodia. This feeding strategy is well suited to life in marine (or aquatic) environments.

Examples of bacterial hyperthermophiles include _________.

Aquificiae and Thermotoga

Evaluate the paragraph and drag the labels to complete the following sentences regarding the growth cycle of Arthrobacter spp

Arthrobacter carry out an unusual growth cycle known as the rod-coccus cycle During exponential phase where cell division is at its maximum rate, the cells are irregular branched rods that divide by snapping division. In stationary phase, when cell division equals cell death, the morphology changes to a coccoid form. When organisms in stationary phase are transferred to fresh media, they once again undergo a morphological change to begin dividing as rods.

Select all characteristics that pertain to Bacillus subtilis and help support the fact that it is an important model organism for the genus Bacillus

B. subtilis has one of the first genomes to be completely sequenced B. subtilis is a nonpathogenic microbe B. subtilis is a facultative anaerobe that can use nitrate as a terminal electron acceptor B. subtilis is the most well studied Gram-positive bacteria

Why are many of the medically important compounds, such as antibiotics, produced by actinobacteria considered "secondary metabolites?" (Check all that apply.)

Because these compounds are not used in "primary metabolism" during active, logarithmic growth. Because these compounds are only produced when actinobacteria are grown in industrial settings. Because these compounds are produced when vegetative cells or hyphae of actinobacteria differentiate into specialized cells such as aerial hyphae. Because these medicinal compounds require further chemical modification prior to clinical use.

What name is given to asexual protist cell division?

Binary fission

Which of the following is found in common with protozoans, bacteria, and archaeons?

Cell wall: maybe

_________ is a filamentous, gliding, thermophilic bacterium that often is isolated from neutral to alkaline hot springs, where it grows in the form of orange-reddish mats, usually in association with cyanobacteria.

Chloroflexus

Drag the descriptions to their corresponding bacterial type in order to review characteristics of important groups of Gram-positive bacteria.

Clostridia - Endospore-forming strict anaerobes Bacilli - Large variety of fermenters and aerobes Staphylococci - Skin inhabitants forming grape-like clusters Lactobacilli - Acid-producing fermenters of foods Streptococci - Diverse group of human pathogens

Drag the diseases to their causative organism's genus in order to test your knowledge of pathogens within class Actinobacteria.

Corynebacterium - Diphtheria Mycobacterium - Leprosy, Tuberculosis Actinomyces - Periodontal Disease, Lumpy jaw in cattle Actinomadura - Ac tinomycetoma Nocardia - Opportunistic infections in AIDS patients

Which of the following organism groups can cause "red tide"?

Dinoflagellata

Match the following protist structures with their cellular locations.

Endoplasm - inner fluid region Pellicle - cell membrane plus a rigid layer just beneath it Plasmalemma - cell membrane Ectoplasm - outer gelatinous region

Which organism group is found wherever rotting organic materials are decomposing? Hint: slime molds

Eumycetozoa

Drag the organisms to their corresponding taxonomic group in order to test your knowledge of protists.

Excavata - Fornicata, Euglenozoa Amoebozoa - Tubulinea, Eumycetozoa Rhizaria - Radiolaria, Forminifera Alveolata - Apicomplexa, Haptophyta, Picozoa Archaeplastida - Ciliophora, Chloroplastida: maybe

Match Radiolaria and Foraminifera with their correct traits.

Foraminifera - These organisms range in size from small single cells to large complexes of cells that have complex reproduction cycles (asexual and sexual) and generally hunt prey using a sticky secreted material on their filopodia. Radiolaria - These organisms are generally found in small clumps of cells that harbor a siliceous material cytoskeleton. They tend to reproduce asexually via fission or budding and trap prey using mucus found on their filopodia.

Which protozoan group contains the pathogen Giardia intestinalis?

Fornicata

How many major cell wall types are distinguished in the actinomycetes, based on peptidoglycan structure and cell wall sugar content?

Four

Analyze the statements below and choose those that describe the characteristics and symbiotic relationships of Frankia spp.

Frankia form multilocular sporangia Frankia form clusters of nonmotile spore when hyphae divide in two planes Frankia can fix nitrogen, and grow symbiotically in the roots of several nonleguminous plants

What name is given to protist cells that produce gametes?

Gamonts

Analyze the statements below and choose those that describe habitats that support growth of Veillonella spp.

Human mouth Bovine gastrointestinal tract Human urogenital tract

Desulfotomaculum is an endospore-forming genus that reduces sulfate and sulfite to ________ ________ during anaerobic respiration.

Hydrogen Sulfide

Fill in the blank in each sentence to describe fermentations performed by lactobacilli.

Lactobacilli perform homolactic fermentation using the Embden-Meyerhof pathway, or heterolactic fermentation via the phosphoketolate pathway Lactobacilli are necessary for the production of fermented milk products such as yogurt and kefir. They are important probiotics in the human digestive tract.

A medically important genus that contains short rods that are facultatively anaerobic, catalase positive, and motile by peritrichous flagella arrangement is the genus _________.

Listeria

In certain geochemically active areas, Acidimethylosilex fumarolicum has been found to perform __________ oxidation within a pH range between .85 and 5.8.

Methane

Match the following events as they occur during paramecium conjugation.

Micronucleus - undergoes meiosis to form four haploid pronuclei, three of which disintegrate Macronucleus - is degraded

Which organelle is used by Trichomonadida organisms for the production of ATP energy?

Mitochondria

Which organelle is found in some Excavata, but does not produce any ATP, despite its evolutionary history?

Mitosomes

For protists, which of the following nutritional strategies uses reduced organic molecules and CO2 as carbon sources?

Mixotrophy

Amoeba that lack a cell wall or other external support structures are termed ________ amoeba.

Naked

Bacillus subtilis, the type species for the genus, is a facultative anaerobe that can use ________ as a terminal electron acceptor during anaerobic conditions.

Nitrate

It is estimated that anammox may contribute as much as 70% to the cycling of __________ in the world's oceans.

Nitrogen

Match the disease with the actinobacterial genus that causes it.

Nocardia - Nocardiosis Corynebacterium - Diphtheria Mycobacterium - Tuberculosis Actinomyces - Lumpy jaw Gardnerella - Bacterial Vaginosis

Check all of the medicinal agents produced by streptomycetes

Nystatin Chloramphenicol Tetracycline

Select the characteristics below that help distinguish heliobacteria from other anoxygenic phototrophic bacteria

Only Heliobacteria are Gram-positive Heliobacteria have light harvesting pigments in their plasma membrane Heliobacteria posses bacteriochlorophyll g

Which protozoan group contains the pathogen Tritrichomonas vaginalis?

Parabasalia

Many drugs used to treat tuberculosis inhibit the synthesis of mycolic acids. Select the statements that accurately describe this approach to treatment. (Check all that apply.)

Patients using such drugs would need to a lengthy course of treatment.

Classify the following attributes as belonging to either purple photosynthetic bacteria or heliobacteria.

Purple Photosynthetic Bacteria - Gram-negative, Reduced sulfur is electron donor for NAD⁺ reduction, Autotrophic, Possess intracellular cytoplasmic membranes, Cannot form endospores, Bacteriochlorophyll a or b Heliobacteria - Gram-positive, Organic carbon electron donor for NAD⁺ reduction, Heterotrophic, Possess only plasma membrane, Some form endospores, Bacteriochlorophyll g

Match the following Actinobacteria with specific characteristics.

Rhodococcus - can degrade PCBs Corynebacterium - palisade cell arrangement Propionibacterium - used in Swiss cheese production Actinoplanetes - flagellated spores Mycobacterium - acid-fast cell wall

If you were studying a bacterium that uses snapping division, what would you look for under the microscope?

Rows of cells lined up side by side

An amoeba covered by material that is either made by the protist itself or collected by the organism from the environment is called a ________ amoeba.

testate

The morphology of diatoms (Bacillariophyta) typically consists of _________.

two silica shells fitting together akin to a Petri dish

Check all that apply to the nutritional strategies used by protists.

Saprophytic Holozoic nutrition Osmotrophy Mixotrophy

Which of the following best describes the molecular signaling that occurs in Dictyostelia?

Several of the internal, starving cells within the pseudoplasmodium release cyclic AMP inducing the aggregation of many cells into a "slug form."

Pick the best answer to identify the terminal electron acceptors used during anaerobic respiration by Desulfotomaculum sp. During anaerobic respiration, Desulfotomaculum sp. reduce _________.

sulfate and sulfite