Viruses, Prokaryotes, and Protista Exam Review

Vocabulary practice flashcards covering Viruses, Bacteria, Archaea, and the Kingdom Protista based on the lecture notes.

Viruses

Non-cellular infectious agents consisting of a protein coat around a core of DNA or RNA that replicate only in a host cell.

Retrovirus

An RNA virus that uses reverse transcriptase to produce viral DNA in a host cell.

Viral Recombination

The process of viral genomes exchanging genes when two viruses infect a host at the same time.

Prokaryotes

Unicellular organisms, including Bacteria and Archaea, characterized by very small cell size (typically $1-5\,\mu\text{m}$) and the absence of a nucleus.

Binary Fission

A form of asexual reproduction in prokaryotes where a cell duplicates its circular chromosome and divides into two genetically identical cells.

Peptidoglycan

A polymer of sugars cross-linked by short polypeptides found in bacterial cell walls.

Gram-positive Bacteria

Bacteria characterized by a cell wall with a thick peptidoglycan layer and no outer membrane.

Gram-negative Bacteria

Bacteria characterized by a cell wall with a thin peptidoglycan layer and an outer membrane composed of lipopolysaccharides and proteins.

Transformation

The horizontal gene transfer process involving the introduction of foreign DNA into a bacterial cell.

Transduction

The process by which DNA is transferred from one bacterium to another by a virus.

Conjugation

The transfer of genetic material between bacterial cells through a pilus.

Cyanobacteria

Photosynthetic oxygen-producing bacteria that can fix atmospheric nitrogen into ammonia ($NH_3$).

Extreme Halophiles

Archaea that thrive in environments with high salt concentrations.

Extreme Thermophiles

Archaea that thrive in extremely high-temperature environments.

Methanogens

A group of Archaea known for producing methane gas.

Kingdom Protista

A diverse collection of eukaryotic lineages that are mostly unicellular, though some are colonial or multicellular.

Mixotrophy

A mode of nutrition that combines autotrophy and heterotrophy, as seen in protists like Euglena.

Trypanosoma

A flagellate blood parasite that causes sleeping sickness and is transmitted by the tsetse fly.

Ciliates

Protists, such as Paramecium, that use cilia for movement and to sweep food into a mouth-like gullet.

Amoebas

Protists that use lobe-shaped pseudopodia for both movement and feeding.

Forams

Protists characterized by having a shell made of calcium carbonate ($CaCO_3$).

Choanoflagellates

The closest known protistan relatives of animals, featuring a flagellum surrounded by a collar of threadlike projections.

Plasmodial Slime Mold

A type of slime mold that forms a plasmodium, which is one large mass of cytoplasm with many nuclei.

Cellular Slime Mold

Slime molds that exist as solitary amoeboid cells but can aggregate into a mobile, multicelled "slug" when food is scarce.

Dinoflagellates

Unicellular algae with two flagella in perpendicular grooves that cause them to spin; they can cause "red tides" during population blooms.

Diatoms

Unicellular algae with a two-part shell made of silica ($SiO_2$) that store food in the form of lipids.

Green Algae

Protists closely related to land plants that contain chlorophyll for photosynthesis and cellulose in their cell walls.

Kelp

Multicellular brown algae that contain the pigment fucoxanthin and serve as a source of algins used as thickeners.