Prokaryotes

Which one, prokaryotes or eukaryotes, are considered to be the most primitive (ancient) organisms on the planet?

Prokaryotes

What are the two domains of prokaryotic organisms

Archaea and Bacteria

What type of organisms are composed of eukaryotic cells?

Fungi, Protists, Plants, and Animals; they all belong to one common domain “Eukarya”

What kind of organisms do not have any membrane-bound organelles?

Prokaryotes (Archaeans and Bacteria)

What kind of organisms have membrane-bound organelles?

Eukaryotes (Protists, Plants Animals, and Fungi)

Are bacteria unicellular, colonial or multcellular organisms?

They can be unicellular or colonial, but no multicellular forms

A spherical-shaped bacterial cell shape is known as a

Coccus (cocci = plural)

A rod-shaped bacterial cell is known as a

Bacillus (bacilli - plural)

A rigid helically-coiled bacterial cell shape is known as a

Spirillum (spirilla = plural)

• Spirochetes - flexible

• Vibrios - comma shaped cells

A chain-like colony of bacterial cells is known as a

“Strep” colony

A grape-like cluster colony of bacterial cells is known as a

“Staph” colony

What are the two main components that make-up the cell walls of bacterial cells?

Peptidoglycan (a glycoprotein: not present in Archaean cell walls) and Lipopolysaccharide (a glycolipid)

What common staining procedure is used first when trying to identify an unknown bacterial specimen?

Gram-stain

What are the four steps, in order, for the Gram-stain procedure?

1. Primary staining

2. Mordant (Iodine)

3. Decolorizing (Ethyl Alcohol)

4. Counter-straining (Safranin = red)

What substance is used as the “Primary Stain” for the Gram-stain procedure?

Crystal violet; Stains the cells purple

What color is Crystal Violet?

Dark purple

What substance is used as a “Mordant” for the Gram-stain procedure?

Iodine; binds the crystal violet tightly to its substrate

What substance is used as a “Decolorizing” agent during the Gram-stain procedure?

Ethyl Alcohol

• Lipid Solvent - dissolves lipopolysaccharide

• Protein Desiccant - shrinks peptidoglycan

What substance is used as the “Counter-stain” during the Gram-stain procedure?

Safranin

What color is Safranin?

Red

After Gram-staining, what color will Gram-positive bacterial colonies appear?

They remain purple

Do Gram-positive colonies decolorize with ethanol?

No because bacterial cells have proportionately more peptidoglycan

After Gram-staining, what color will Gram-negative bacterial colonies appear?

They appear pinkish-red

Do Gram-negative bacterial colonies decolorize with ethanol?

Yes (1)

Do Gram-positive bacteria typically have more peptidoglycan or more lipopolysaccharide in their cell wall?

Peptiodglycan

Do Gram-negative bacteria typically have more peptidoglycan or more lipopolysaccharide in their cell wall?

Lipopolysaccharide

A thick-walled, genetically identical, and metabolically dormant cell, resistant to harsh/unfavorable environmental conditions, and located within a parent bacterial cell, is known as an

Endospore

A gelatinous material located outside the cell wall of some bacterial cells, helping to adhere the cell to its substrate, is known as a

Capsule

Numerous filamentous extensions of the cell wall and plasma membrane extending from the cells of some bacteria and helping adhere the cells to their substrate known as

Fimbriae

A filamentous elongation of the cell wall and plasma membrane that can be used to help a bacterial cell pass genetic information from one cell to another is known as

Pilus (Pili is plural)

The term _____ refers to an organism’s ability to move

Motility

Roughly, what percentage of bacteria have the ability to move?

50%

What are the three methods of motility used by bacteria?

1. Gliding on slimy threads

2. Twisting of helically-coiled cells

3. Flagella

Movement toward or away from the specified stimulus is knowns as

Taxis

Specifically, movement toward a specified stimulus is known as _____

Positive

Specifically, movement away a specified stimulus is known as

Negative

Specifically, movement toward light known as _____

Positive Phototaxis

Specifically, movement away from light known as _____

Negative Phototaxis

Specifically, movement toward a chemical stimulus is known as _____

Positive Chemotaxis

Specifically, movement away a chemical stimulus is known as _____

Negative Chemotaxis

Do the flagella of all prokaryotes contain a “9+2” microtubules arrangment?

No, instead they have a central core of the protein flagellin

Do the flagella of all eukaryotic cells contain a “9+2” microtubules arrangement?

Yes (2)

Do prokaryotes reproduce asexually, sexually, or both?

Asexually

Prokaryotic cells reproduce asexually through a process called

Binary Fission, resulting in clones (genetically identical daughter cells)

Is a binary fission a form of asexual reproduction or is it a form of sexual reproduction?

Asexual reproduction

Following binary fission, are the resulting daughter cells genetically identical or genetically different from the parent cell?

Identical

TRUE or FALSE: Binary fission helps prokaryotes incorporate genetic diversity into their population

FALSE

What is the ultimate source of all genetic variation in all populations of organisms?

Random Mutation

Is mutation a random process or can an organism mutate on demand?

Random

Aside from random mutation, what are three ways that prokaryotes can incorporate genetic diversity into the population?

1. Transformation

2. Transduction

3. Conjugation

The ability of prokaryotes to absorb and express extracellular DNA is known as

Transformation

Genetic diversity introduce by a viral infection in prokaryotes is known as

Transduction

Genetic diversity incorporated among prokaryotic populations through the transfer of DNA from one bacterial cell to another bacterial cells using a cytoplasmic extension called a pilus is known as

Conjugation

A type of nutritional mode in which the organism is able to use light energy to perform carbon fixation is known as

Photoautotrophs

A type of nutritional mode in which the organism uses energy from the oxidation of inorganic mineral ions to perform carbon fixation is known as

Chemoautotrophs

A type of nutritional mode in which the organism has the ability to use light energy for the production of ATP but cannot perform carbon fixation is known as

Photoheterotrophs

A type of nutritional mode in which the organism cannot use light energy and cannot perform carbon fixation is known as

Chemoheterobtrophs

The ability of some bacteria to convert molecular nitrogen (N₂) into a nitrogenous compound such as nitrite (NO₂) and nitrate (NO₃), ammonia (NH₃) or ammonium (NH₄⁺), is known as

Nitrogram Fixation

An organism that must have oxygen to survive is knows as a

Obligate Aerobes

An organism that can use oxygen when available to support aerobic respiration, but in its absence is able to switch over to anaerobic fermentation, is known as a

Facultative Aerobes

An organism that can only survive in an oxygen-free environment is known as a

Obligate Anaerobes (oxygen is toxic)

What are the following ecologically significant aspect of prokaryotes:

• Decomposers

• Nitrogen-fixation

• Commerical Production

• Bioremediation

• Symbionts

The term _____ refers to the use of microorganisms to cleanup wastes

Bioremedation

In all ecosystems, organism that breakdown the bodies of dead organisms and therefore recycle their nutrients for the next generation are known as

Decomposers

Disease-causing bacteria are said to be

Pathogenic

Which of the following (mutualistic, commensalistic parasitic), would best describe a pathogenic bacterium?

Parasitic (Causes bacterial infection)

Members of what prokaryotic “Domain” have cell walls that do not contain peptidoglycan and are often extremophiles?

Archaea

Organisms capable of thriving in extreme environmental conditions are referred to as

Extremophiles

What “group” of Archaeans contains the overall majority of extremophiles, including the methanogens, the halophiles and some of the thermophiles?

Euryarchaeota

What “group” of Archaeans contains the majority of thermophiles, including those inhabiting geothermal pools?

Crenarchaeota

What relatively new “group” of Archaeans contains members that are thermophiles?

Korarchaeota (non-extremophilic archaeans)

What “group” of Archaeans contains members that are less than 0.5 micrometers in diameter?

Nanoarchaeota

Members of what Prokaryotic “Domain” have cell walls that do contain peptidoglycan?

Bacteria

What “group” of bacteria includes nitrogen-fixing bacteria, the ancestors to eukaryotic mitochondria, E.coli, and pathogenic members that cause illnesses such as Legionnaire’s Disease, Salmonella, Cholera, and Rocky Mountain Spotted Fever?

Proteobacteria

What “group” of bacteria contains members that are all endosymbiotic parasites that are responsible for illnesses such as the STD Chlamydia, respiratory infections and eye infections?

Chlamydias

What “group” of bacteria contains members that have helically-coiled cells and includes the organisms responsible for the STD Syphilis and the tick-vectored illness Lyme Disease?

Spirochaetes

What “group” of bacteria all test positive with the Gram stain test that includes the organism responsible for the smell of freshly-plowed earth, as well as notable pathogens that cause Anthrax, Botulism, Tuberculosis and Leprosy?

Gram-Positive Bacteria

What “group” of bacteria are photosynthetic and often commonly referred to as the “Blue-Green Algae”?

Cyanobacteria (2)

In addition to Chlorophyll, the cyanobacteria utilize two other pigments for photosynthesis, a blue one called _____ and a red one called _____?

Phycocyanin (Blue) and Phycoerythrin (Red)

What “group” of bacteria contains the organism believed to be the ancestors of the eukaryotic organelle called Cholorplast?

Cyanobacteria (1)