CRHS Viruses & Taxonomy

Pathogen

disease-causing agent

Virus

particle made up of nucleic acid, protein, and in some cases lipids, that can replicate only by infecting living cells; antibiotics do NOT work on these

Capsid

outer protein coat of a virus

Host cell

a cell that harbors foreign molecules, viruses, or microorganisms

Lysis

the breaking down of a cell

Lytic cycle

process in which a virus enters a cell, makes a copy of itself, and causes the cell to burst

Lysogenic cycle

process by which a virus embeds its DNA into the DNA of the host cell and is replicated along with the host cell's DNA

Retrovirus

virus that contains RNA, instead of DNA, as its genetic information (ex. HIV)

HIV (Human immunodeficiency virus)

a retrovirus that uses the DNA of white blood cells called helper T cells to replicate; causes the disease known as AIDS

Helper T cell

a type of white blood cell, that play an important role in the immune system; HIV attacks these cells

Influenza

usually referred to as the flu or grippe, this is a highly infectious respiratory disease; also a retrovirus

Bacteriophage

virus that uses the DNA of bacteria to replicate

Prophage

the viral DNA that is embedded in the host cell's DNA

Other diseases caused by viruses

Common cold, smallpox, warts, chickenpox, measles, hepatitis A, hepatitis B, hepatitis C, West Nile, polio

Taxomony

discipline of classifying organisms and assigning each organism a universally accepted name; father is Carolus Linneaus

Classification system

a method to group and categorize organisms based on similarities into taxa

Taxon (plural: taxa)

a group or level of organization into which organisms are classified

Binominal nomenclature

classification system developed by Carolus Linnaeus in which each species is assigned a two-part scientific name

Scientific name (Genus species)

the taxonomic name of an organism that consists of the genus and species

Domain

the highest level of classification; larger than a kingdom

Kingdom

a group of closely related phylums

Phylum

a group of closely related classes

Class

a group of closely related orders

Order

a group of closely related families

Family

a group of closely related genus'

Genus

group of closely related species

Species

group of similar organisms that can interbreed and produce fertile offspring

Cladogram

diagram that shows the evolutionary relationships among a group of organisms

Derived characteristics

characteristic that appears in recent parts of a lineage, but not in its older members

Common ancestor

the most recent ancestral form or species from which two different species evolved

Dichotomous key

a tool that allows the user to determine the identity of organims consisting of a series of choices that lead the user to the correct name of a given item

Domain Bacteria

includes Kingdom Eubacteria (prokaryotes)

Domain Archea

includes Kingdom Archeabacteria (prokaryotes)

Domain Eukarya

includes Kingdoms Protista, Fungi, Plantae and Animalia (eukaryotes)

Kingdom Eubacteria

a kingdom of prokaryotic organisms that contains mostly free-living and common bacteria; classified under Domain Bacteria

Kingdom Archeabacteria

a kingdom of prokaryotic organisms that contains mostly bacteria that are limited to extreme environments; classified under Domain Archea

Kingdom Animalia

a kingdom a of multicellular, eukaryotic organisms that are free-moving, and lack cell walls; classified under Domain Eukarya

Kingdom Plantae

a kingdom a of multicellular, eukaryotic organisms that have a cell wall made of cellulose; classified under Domain Eukarya

Kingdom Fungi

a kingdom a of multicellular, eukaryotic organisms, such as mushrooms and molds, that have a cell wall containing chitin; classified under Domain Eukarya

Kingdom Protista

a kingdom of a variety of eukaryotic unicellular, colonial, and multicellular organisms, such as ameoba, euglena, paramecieum, protozoans, algae, etc.; classified under Domain Eukarya