Upgrade to remove ads
Only $35.99/year

Da_Watts_Chapter1 KeyTerms

Terms in this set (26)

adaptation
Any heritable trait that increases the fitness of an individual with that trait, compared with individuals without that trait, in a particular environment.
artificial selection
Deliberate manipulation by humans, as in animal and plant breeding, of the genetic composition of a population by allowing only individuals with desirable traits to reproduce.
cell
A highly organized compartment bounded by a thin, flexible structure (plasma membrane) and containing concentrated chemicals in an aqueous (watery) solution. The basic structural and functional unit of all organisms.
cell theory
The theory that all organisms are made of cells and that all cells come from preexisting cells.
class
In Linnaeus' system, a taxonomic category above the order level and below the phylum level.
control
In a scientific experiment, a group of organisms or samples that do not receive the experimental treatment but are otherwise identical to the group that does.
domain
(1) A section of a protein that has a distinctive tertiary structure and function. (2) A taxonomic category, based on similarities in basic cellular biochemistry, above the kingdom level. The three recognized domains are Bacteria, Archaea, and Eukarya.
eukaryote
A member of the domain Eukarya; an organism whose cells contain a nucleus, numerous membrane-bound organelles, and an extensive cytoskeleton. May be unicellular or multicellular. Compare with prokaryote.
evolution
(1) The theory that all organisms on Earth are related by common ancestry and that they have changed over time, predominantly via natural selection. (2) Any change in the genetic characteristics of a population over time, especially, a change in allele frequencies.
genus
(plural: genera). In Linnaeus' system, a taxonomic category of closely related species. Always italicized and capitalized to indicate that it is a recognized scientific genus.
heritable
Referring to traits that can be transmitted from one generation to the next.
hypothesis
A proposed explanation for a phenomenon or for a set of observations.
natural selection
The process by which individuals with certain heritable traits tend to produce more surviving offspring than do individuals without those traits, often leading to a change in the genetic makeup of the population. A major mechanism of evolution.
null hypothesis
A hypothesis that specifies what the results of an experiment will be if the main hypothesis being tested is wrong. Often states that there will be no difference between experimental groups.
organism
Any living entity that contains one or more cells.
phylogeny
The evolutionary history of a group of organisms.
phylum
In Linnaeus' system, a taxonomic category above the class level and below the kingdom level. In plants, sometimes called a division.
population
A group of individuals of the same species living in the same geographic area at the same time.
prediction
A measurable or observable result of an experiment based on a particular hypothesis. A correct prediction provides support for the hypothesis being tested.
prokaryote
A member of the domain Bacteria or Archaea; a unicellular organism lacking a nucleus and containing relatively few organelles or cytoskeletal components. Compare with eukaryote.
ribosomal RNA (rRNA)
A RNA molecule that forms part of the structure of a ribosome.
speciation
The evolution of two or more distinct species from a single ancestral species.
taxon
(plural: taxa) Any named group of organisms at any level of a classification system.
taxonomy
Any named group of organisms at any level of a classification system.
theory
A proposed explanation for a broad class of phenomena or observations.
tree of life
A diagram depicting the genealogical relationships of all living organisms on Earth, with a single ancestral species at the base.
Sets found in the same folder