Bio number 3. Chapter 27: The Prokaryotes - Bacteria and Archaea Diversity

Vocabulary flashcards covering bacterial reproduction, genetic transfer, cell envelope structure, bacterial categories, metabolic modes, and archaeal diversity based on Chapter 27.

Binary fission

A form of asexual bacterial reproduction in which a bacterial cell replicates its genome and divides in half, producing two daughter cell clones.

Conjugation

A mechanism of bacterial genetic recombination where a donor cell passes DNA to a recipient cell by way of a sex pilus.

Transformation

A mechanism of bacterial genetic recombination in which a bacterium takes up DNA from the environment that was released by dead bacteria.

Transduction

A mechanism of bacterial genetic recombination where viruses carry bacterial DNA from cell to cell.

Horizontal gene transfer

The movement of genes among individuals from different species, such as the transfer of virulence genes between bacteria.

Endospore

A resistant structure formed by some bacteria during harsh conditions as a strategy for survival rather than reproduction.

Peptidoglycan

A network of sugar polymers cross-linked by polypeptides found in bacterial cell walls.

Gram stain

A technique scientists use to classify bacteria based on their cell wall composition.

Gram-positive bacteria

Bacteria with simpler cell walls containing a thick layer of peptidoglycan that traps crystal violet and stains purple.

Gram-negative bacteria

Bacteria with a thin or no peptidoglycan layer and an outer membrane that can be toxic, staining pink when rinsed and revealing red dye.

Gram-positive bacillus examples

Bacillus anthracis, Clostridium botulinum, Clostridium tetani, and Clostridium difficile.

Gram-negative bacillus examples

Escherichia coli, Salmonella enterica serovars, Shigella flexneri, and Serratia marcescens.

Gram-positive coccus examples

Staphylococcus aureus, Streptococcus pneumoniae, and Streptococcus pyogenes.

Gram-negative coccus examples

Neisseria meningitidis, Neisseria gonorrhoeae, and Hemophilus influenzae.

Gram-negative spirillum examples

Campylobacter jejuni, Helicobacter pylori, Borrelia burgdorferi, and Treponema pallidum.

Heterotrophs

Organisms that require an outside source of organic compounds for nutrition.

Autotrophs

Organisms that require only CO2 as a carbon source.

Chemoautotrophs

Autotrophic organisms that extract energy from inorganic molecules or minerals.

Photoautotrophs

Autotrophic organisms that obtain energy from solar light.

Extremophiles

Archaea that live in extreme environments, including halophiles and thermophiles.

Extreme halophiles

Archaea that live in highly saline environments.

Extreme thermophiles

Archaea that thrive in very hot or cold environments.

Methanogens

Chemotrophic, strict anaerobic archaea that are poisoned by O2, live in swamps, marshes, or intestinal tracts, and extract energy from carbon dioxide and water to produce methane as a waste product.

Haloquadratum walsbyi

A phototrophic halophilic archaea species.

Heterocysts

Specialized nitrogen-fixing cells in the cyanobacterium Anabaena that exchange metabolic products with photosynthetic cells.

Rhizobium

A genus of bacteria that forms root nodules in legumes and fixes atmospheric N2 through mutualism.

Photoblepharon palpebratum

An organism that possesses a specialized organ harboring bioluminescent bacteria to attract prey and signal potential mates in a mutualistic relationship.

Pathogens

Bacteria that can produce disease.

Virulence factors

Encoded traits by extra genes in pathogenic bacteria, such as the toxin produced by E. coli O157:H7 that damages intestinal lining and causes bloody diarrhea.