Prokaryotes

Prokaryotes

Organisms that include Bacteria and Archaea, characterized by being unicellular, lacking a nucleus, and having no membrane-bound organelles.

Binary Fission

Asexual reproduction in prokaryotes where DNA replicates and the cell splits into two identical daughter cells.

Gram-positive

Bacteria with a thick peptidoglycan cell wall that retain the violet stain used in Gram staining.

Nitrogen Fixation

The process by which certain prokaryotes convert atmospheric nitrogen into a usable form for plants.

Autotrophs

Organisms that produce their own food; can be photoautotrophs (using light energy) or chemoautotrophs (using chemical energy).

Cyanobacteria

Photosynthetic bacteria that produce oxygen, often found in aquatic environments.

Conjugation

A process of sexual genetic exchange in prokaryotes where DNA is transferred between cells through a bridge.

Heterotrophs

Organisms that depend on other organisms for food; includes chemoheterotrophs and photoheterotrophs.

Methanogens

A type of archaea that produce methane, commonly found in anaerobic environments such as intestines.

Facultative anaerobes

Organisms that can survive with or without oxygen.

Endospores

Dormant survival structures formed by some bacteria to withstand extreme conditions.

Peptidoglycan

A polymer that forms the cell wall of many bacteria, providing structural support.

Photoheterotrophs

Organisms that obtain energy from light but require organic compounds as a carbon source.

Extremophiles

Archaea that thrive in extreme environments, such as high heat or high salt.

Gram-negative

Bacteria with a thin peptidoglycan layer and an outer lipid membrane that do not retain the violet stain in Gram staining.

Decomposers

Organisms that break down dead material and recycle nutrients back into the ecosystem.