Prokaryotes, Eukaryotes, Bacteria, Archaea & Viruses Lecture Notes

A set of vocabulary flashcards covering the characteristics, classification, and reproduction of prokaryotes, eukaryotes, bacteria, archaea, and viruses based on lecture materials.

Domain

The highest rank of organisms, positioned above the Kingdom level.

Archaea (Domain)

All prokaryotic microorganisms that are extreme-loving and are characterized by having unusual ether-linked lipids in their cell membranes.

Bacteria (Domain)

All prokaryotic microorganisms that do not have a nucleus and are typically classified by three basic shapes: spherical, rod-shaped, or spiral.

Eukarya

A domain that includes all life with a nucleus and membrane-bound organelles, including most multicellular life such as plants and animals.

Endosymbiosis

The theory that eukaryotes evolved from separate prokaryotic cells that joined in a symbiotic union, with one organism taking up permanent residence inside another.

Prokaryotes

Simplest forms of life measuring $1-10ʹm$ that appeared $3.5$ billion years ago; they lack a nucleus and membrane-bound organelles.

Eukaryotes

Complex organisms measuring $100-1000ʹm$ that appeared $1.5$ billion years ago; they contain a nucleus, linear DNA, and mitochondria.

Cocci

Spherical-shaped bacteria, derived from the Greek word for berries.

Bacilli

Rod-shaped bacteria, derived from the Latin word for stick.

Spirochetes

Spiral-shaped bacteria, derived from the Greek word for long hair.

Binary Fission

An asexual process where a bacterial cell divides to produce two identical cells, allowing for rapid reproduction without genetic recombination.

Transformation

A type of bacterial genetic mixing where bacteria take up pieces of free DNA fragments from the environment.

Conjugation

A process where two bacterial cells temporarily join and directly exchange genetic material, usually involving plasmids, through a mating bridge.

Transduction

A process where viruses that infect bacteria carry genes from one cell and inject them into another.

Quorum Sensing

A form of chemical communication used by bacteria to synchronize coordinated attacks based on population density.

Methanogens

Archaea that live in oxygen-free environments, such as swamps or sewage plants, and produce methane.

Halophiles

A classification of Archaea that are salt-loving.

Thermoacidophiles

Heat and acid-loving Archaea that grow best at temperatures above $80\,^∘\text{C}$, often found in hot sulfur springs or volcanoes.

Peptidoglycan

A polymer found in the cell walls of most Bacteria but absent in the cell walls of Archaea.

Capsid

A protective protein coat that accounts for $95\%$ of a virus's total mass and gives it its particular shape.

Antigens

Extensions on a virus that allow it to identify, attack, and enter a target host cell.

Bacteriophage

A specialized virus that specifically infects bacteria.

Lytic Cycle

A viral reproduction cycle where the virus replicates in the host's cytoplasm and causes the cell to lyse or break open immediately.

Lysogenic Cycle

A viral reproduction cycle where viral DNA is integrated into the host's chromosome as a provirus and can remain dormant for years.

Vaccines

Liquid preparations of dead or weakened viral or bacterial cells that work by pre-infecting the body to stimulate antibody production.