BIO121 Chapter 1

Montco BIO121 Chapter 1 Key Terms

artificial selection

The selective breeding of domesticated plants and animals to promote the occurrence of desirable traits

biology

the scientific study of life

biosphere

The entire portion of Earth inhabited by life; the sum of all the planet’s ecosystems

cell

A basic unit of living matter separated from its environment by a plasma membrane; the fundamental structural unit of life

community

A basic unit of living matter separated from its environment by a plasma membrane; the fundamental structural unit of life

controlled experiment

An experiment in which an experimental group is compared with a control group that varies only in the factor being tested

data

recorded observations

dependent variable

A factor whose value is measured in an experiment to see whether it is influenced by changes in another factor

domain

A taxonomic category above the kingdom level. The three domains of life are Archaea, Bacteria, and Eukarya

ecosystem

All the organisms in a given area, along with the nonliving (abiotic) factors with which they interact; a biological community and its physical environment

emergent properties

New properties that arise with each step upward in the hierarchy of life, owing to the arrangement and interactions of parts as complexity increases

evolution

Descent with modification; the idea that living species are descendants of ancestral species that were different from present-day ones; also, the genetic changes in a population from generation to generation

experiment

A scientific test. Often carried out under controlled conditions that involve manipulating one factor in a system in order to see the effects of changing that factor

gene

A discrete unit of hereditary information consisting of a specific nucleotide sequence in DNA (or RNA, in some viruses). Most of the genes of a eukaryote are located in its chromosomal DNA; a few are carried by the DNA of mitochondria and chloroplasts

gene expression

The process whereby genetic information flows from genes to proteins; the flow of genetic information from the genotype to the phenotype

hypothesis

A testable explanation for a set of observations based on the available data

independent variable

A factor whose value is manipulated or changed during an experiment to reveal possible effects on another factor

molecule

Two or more atoms held together by covalent bonds

natural selection

A process in which individuals with certain inherited traits are more likely to survive and reproduce than are individuals that do not have those traits

organ

A specialized structure composed of several different types of tissues that together perform specific functions

organ system

A group of organs that work together in performing vital body functions

organelle

A membrane-enclosed structure with a specialized function within a cell

organism

An individual living thing, consisting of one or more cells

population

A group of individuals belonging to one species that live in the same geographic area and can potentially interbreed

science

An approach to understanding the natural world based on verifiable evidence

systems biology

An approach to studying biology that aims to model the dynamic behavior of whole biological systems based on a study of the interactions among the system’s parts

technology

The application of scientific knowledge for a specific purpose, often involving industry or commerce but also including uses in basic research

theory

A widely accepted explanatory idea that is broader in scope than a hypothesis, generates new hypotheses, and is supported by a large body of evidence

tissue

An integrated group of cells with a common function, structure, or both