Chapter 1 vocabulary

A proposed explanation for a broad class of phenomena or observations.

A proposed explanation for a phenomenon or for a set of observations.

A measurable or observable result of an experiment based on a particular hypothesis. A correct prediction provides support for the hypothesis being tested.

The theory that all organisms are made of cells and that all cells come from preexisting cells.

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.

The average time between a mother’s first offspring and her daughter’s first offspring.

• (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.

The phrase used by Darwin to describe his hypothesis of evolution by 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.

Referring to traits that can be transmitted from one generation to the next.

A group of individuals of the same species living in the same geographic area at the same time.

The relative ability of an individual to produce viable offspring compared with other individuals in the same population. Also called Darwinian fitness.

Any heritable trait that increases the fitness of an individual with that trait, compared with individuals without that trait, in a particular environment.

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.

The evolution of two or more distinct species from a single ancestral species.

A diagram depicting the genealogical relationships of all living organisms on Earth, with a single ancestral species at the base.

The branch of biology concerned with the classification and naming of organisms.

Any named group of organisms at any level of a classification system.

A system of naming species by using two-part Latinized names composed of a genus name and a species name (e.g., Homo sapiens, humans; Canis familiaris, dogs). Always italicized, with genus name capitalized.

• (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.

In Linnaeus’ system, a taxonomic category above the phylum level and below the domain level.

In Linnaeus’ system, a taxonomic category above the class level and below the kingdom level. In plants, sometimes called a division.

In Linnaeus’ system, a taxonomic category of closely related species. Always italicized and capitalized to indicate that it is a recognized scientific genus.

A distinct, identifiable group of populations that is thought to be evolutionarily independent of other populations and whose members can interbreed. Generally distinct from other species in appearance, behavior, habitat, ecology, genetic characteristics, etc.

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.

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.

The evolutionary history of a group of organisms.

A diagram that depicts the evolutionary history of a group of species and the relationships among them.

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.

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.