Biology Chapter on Prokaryotes and Taxonomy

Bacteria and archaea.

Taxonomy is the science of classification of living organisms based on similarities and relationships.

Nomenclature assigns names to various taxa according to international rules.

<p>Carolus Linnaeus developed the binomial system, which consists of the genus and the specific epithet.</p> Signup and view all the answers

<p>Cocci (spherical), bacilli (rod-shaped), and spirilla (curved or spiral-shaped).</p> Signup and view all the answers

<p>Binary fission is the process by which a bacterial cell splits into two cells.</p> Signup and view all the answers

<p>Generation time refers to the time it takes for one bacterial cell to divide into two cells.</p> Signup and view all the answers

<p>Protists, classified in the Kingdom Protista, include algae and protozoa, while monerans refer specifically to bacteria and archaea.</p> Signup and view all the answers

<p>A flagella stain helps demonstrate the presence, number, and location of flagella on bacterial cells.</p> Signup and view all the answers

<p>Chemolithotrophy is a metabolic process where organisms obtain energy from inorganic compounds, and those organisms are called chemolithotrophs.</p> Signup and view all the answers

<p>Phototrophic microorganisms can convert light energy into chemical energy, avoiding competition for chemical energy sources.</p> Signup and view all the answers

<p>Heterotrophs require organic compounds for carbon, while autotrophs use carbon dioxide (CO2) as their carbon source.</p> Signup and view all the answers

<p>The largest phylum of Bacteria is Proteobacteria, which includes a diverse range of prokaryotic species.</p> Signup and view all the answers

<p>Motile bacilli are bacteria that can move using flagella as their means of locomotion.</p> Signup and view all the answers

<p>Pigments in phototrophic microorganisms allow them to capture light energy for converting into chemical energy.</p> Signup and view all the answers

<p>Pathogenic prokaryotes within the domain Bacteria are responsible for causing diseases in various hosts.</p> Signup and view all the answers

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

<p>The Domain Archaea includes many extremophiles that live in extreme environments such as very high or low pH levels.</p> Signup and view all the answers

<p>Extremophiles can be found in volcanic hot springs, polar ice, extremely salty water, and deep-sea hydrothermal vents.</p> Signup and view all the answers

<p>Archaea are genetically more closely related to eukaryotes than to bacteria.</p> Signup and view all the answers

<p>Methanogens produce methane.</p> Signup and view all the answers

<p>Obligate aerobes require oxygen concentrations similar to that of room air, while microaerophilic aerobes need lower concentrations of oxygen for growth.</p> Signup and view all the answers

<p>Neisseria gonorrhoeae is an example of a microaerophilic bacterium.</p> Signup and view all the answers

<p>Obligate anaerobes must grow in an anaerobic environment, which contains no oxygen.</p> Signup and view all the answers

<p>Facultative anaerobes can survive in both the presence and absence of oxygen, adapting between 0% to 21% O2.</p> Signup and view all the answers

<p>Aerotolerant anaerobes do not require oxygen for growth but can survive in its presence.</p> Signup and view all the answers

<p>Microorganisms can thrive in extreme environments like boiling hot springs or highly acidic lakes.</p> Signup and view all the answers

<p>The family Enterobacteriaceae includes many facultative anaerobes commonly isolated from clinical specimens.</p> Signup and view all the answers

<p>Microaerophilic bacteria require lower oxygen levels than obligate aerobes, who need higher oxygen concentrations.</p> Signup and view all the answers

<p>Cocci bacteria can be arranged in pairs (diplococci), chains (streptococci), clusters (staphylococci), packets of four (tetrad), and packets of eight (octads).</p> Signup and view all the answers

<p>Bacilli bacteria appear as rod-shaped structures, and they can also exist in pairs (diplobacilli) or chains (streptobacilli).</p> Signup and view all the answers

<p>Spirochetes are spiral-shaped bacteria, which differ from bacilli that are typically rod-shaped. Spirochetes have a unique morphology that sets them apart from traditional bacilli.</p> Signup and view all the answers

<p>Pleomorphism is the ability of bacteria to exist in a variety of shapes, and it is particularly seen in bacteria in the genus Mycoplasma. These bacteria lack cell walls, leading to their diverse morphologies.</p> Signup and view all the answers

<p>Fixation is crucial for preserving bacterial morphology during staining and can be accomplished through methods such as heat fixation or methanol fixation. Proper fixation prevents distortion of the cell's appearance.</p> Signup and view all the answers

<p>Heat fixation involves passing the smear through a flame, which can potentially distort cell morphology, while methanol fixation involves flooding the smear with methanol, providing a more reliable fixation technique.</p> Signup and view all the answers

<p>The color depends on the chemical composition of the bacterial cell wall.</p> Signup and view all the answers

<p>Dr. Hans Christian Gram developed the Gram stain in 1883, which helps observe bacterial cell morphology, such as size, shape, arrangement, and cell wall composition.</p> Signup and view all the answers

<p>They have a thick layer of peptidoglycan in their cell walls.</p> Signup and view all the answers

<p>Specific stains are used to enhance the visual characteristics of bacteria, allowing for the observation of details such as shape, size, cell wall structure, and additional features like capsules or flagella.</p> Signup and view all the answers

<p>Gram-negative bacteria have a thin layer of peptidoglycan, allowing the crystal violet–iodine complex to be easily removed.</p> Signup and view all the answers

<p>Gram-variable bacteria do not consistently display either blue to purple or pink to red after staining; an example is Mycobacterium tuberculosis.</p> Signup and view all the answers

<p>Bacterial motility is crucial for movement and is often associated with flagella or axial filaments.</p> Signup and view all the answers

<p>Bacteria that cannot swim exhibit glucose or alternative forms of motility.</p> Signup and view all the answers

<p>Microbial diversity has been evolving for nearly 4 billion years.</p> Signup and view all the answers

<p>Cell size and morphology (shape) are two factors contributing to microbial diversity.</p> Signup and view all the answers