A specialized area of biology that deals with living things ordinarily too small to be seen without magnification, including bacteria, archaea, fungi, protozoa, and viruses.
Invisible to the naked eye.
A living thing ordinarily too small to be seen without magnification; an organism of microscopic size
bacteria (singular, bacterium)
Category of prokaryotes with peptidoglycan in their cell walls and circular chromosome(s). This grounp of small cells is widely distributed in the earth's habitats.
Photosynthetic, plantlike organisms that generally lack the complex structure of plants; they may be single-celled or multicellular and inhabit diverse habitats such as marine and freshwater environments, glaciers, and hot springs.
A group of single-celled, eukaryotic organisms.
Parasitic invertebrate animals such as worms.
fungi (singular, fungus)
Macroscopic and microscopic heterotrophic eukaryotic organisms that can be uni- or multicellular.
Microscopic, acellular agent composed of nucleic acid surrounded by a protein coat.
The relationship between a parasite and its host in which the parasite lives on or within the host and damages the host in some way; characteristic of an organism considered to be a parasite.
A member of the domain Eukarya whose cells have a well-defined nucleus and membrane-bound organeles; includes plants, animals, fungi, protozoa, and algae.
A single-celled organism that does not have special structures such as a nucleus or membrane-bound organelles; includes bacteria and archaea.
Present everywhere at the same time.
Scientific principle that states that living things change gradually through hundreds of millions of years,and these changes are expressed in structural and functional adaptions in each organism. Evolution presumes that those traits that favor survival are preserved and passed on to following generations, and those traits that do not favor survival are lost.
Theory of Evolution
The evidence cited to explain how evolution occurs.
A process occurring in plants, algae, and some bacteria that traps the sun's energy and converts it to ATP in the cell. This energy is used to fix CO2 into organic compounds.
The breakdown of dead matter and wastes into simple compounds that can be directed back into the natural cycle of living things.
A field involving deliberate alterations (recombinations) of the genomes of microbes, plants, and animals through special technological processes.
recombinant DNA technology
A technology, also known as genetic engineering, that deliberately modifies the genetic structure of an organism to create novel products, microbes, animals, plants, and viruses.
Decomposition of harmful chemicals by microbes or consortia of microbes.
Any agent (usually a virus, bacterium, fungus, protozoan, or helminth) that causes disease.
One of the three domains of living organisms as proposed by Woese.
One of the three domains (sometimes called superkingdoms) of living organisms, as proposed by Woese; all eukaryotic organisms.
When capitalized can refer to one of the three domains of living organisms proposed by Woese, containing all nonarchaea prokaryotes.
A more specific name for a virus when it is outside of its hosts cell.
A small component of eukaryotic cells that is bounded by a membrane and specialized in function.
An organism that lives on or within another organism (the host), from which it obtains nutrients and enjoys protection. The parasite produces some degree of harm in the host.
Organism in which smaller organisms or viruses live, feed, and produce.
Early belief that living things arose from vital forces present in nonliving, or decomposing, matter.
The belief in spontaneous generation as a source of life.
Belief that living things can only arise from others of the same kind.
polymerase chain reaction (PCR)
A technique that amplifies segments of DNA for testing. Using denaturation, primers, and heat-resistant DNA polymerase, the number can be increased several-million-fold.
A complex association that arises from a mixture of microorganisms growing together on the surface of a habitat.
Principles and procedures for the systematic pursuit of knowledge, involving the recognition and formulation of a problem, the collection of data through observation and experimentation, and the formulation and testing of a hypothesis.
A tentative explanation of what has been observed or measured.
A collection of statements, propositions, or concepts that explains or accounts for a natural event.
Completely free of all life forms, including spores and viruses.
Methods of handling microbial cultures, patient specimens, and other sources of microbes in a way that prevents infection of the handler and others who may be exposed.
germ theory of disease
A theory first originating in the 1800s that proposed that microoorganisms can be the cause of diseases. The concept is actually so well established in the present time that is\t is considered a fact.
A set system for scientifically naming organisms, enzymes, anatomical structures, and so on.
The formal system for organizing, classifying, and naming living things.
Scientific method of assigning names to organisms that employs two names to identify every organism - genus name plus species name.
In the levels of classification, the broadest general category to which an organism is assigned. Members of a domain share only one or a few general characteristics.
In the levels of classification, the second division from more general to more specific. Each domain is divided into kingdoms.
In the levels of classification, the third level of classification from general to more specific. Each kingdom is divided into numerous phyla.
In levels of classification, the division of organisms that follow phylum
In the levels of classification, the division of organisms that follows class. Increasingly similarity may be noticed among organisms assigned to the same order.
In the levels of classification, a midlevel division organisms that groups more closely related organisms than previous levels. An order is divided into families.
In the levels of classification, the second most specific level. A family is divided into several genera.
In the levels of classification, the most specific level of organization.