Biology 101: Chapter 1 - The Study of Life

Vocabulary practice flashcards covering introductory concepts in Biology 101 Chapter 1, including cell theory, genetic information, evolution, natural selection, taxonomy, and scientific methods.

Five Fundamental Characteristics of Life

The five traits shared by all living organisms: cells, replication, information, energy, and evolution.

Cell

The smallest membrane-bound unit that makes things alive, forming the structure of all organisms.

Replication

The fundamental characteristic of life where all organisms are capable of reproduction.

Information (Characteristic of Life)

The ability of organisms to process hereditary information encoded in genes as well as respond to environmental signals.

Energy (Characteristic of Life)

The requirement that all organisms acquire and use energy to stay alive.

Evolution (Characteristic of Life)

The process by which populations of organisms continually change and adapt over time.

Robert Hooke

Devised a microscope with $30\times$ magnification in 1665 and observed small compartments in dead cork tissue invisible to the naked eye, which he termed 'cells'.

Anton van Leeuwenhoek

Devised microscopes with $300\times$ magnification and was the first to observe single-celled organisms, which he termed 'animalcules'.

Cell Theory (First Part)

The core biological principle stating that all organisms are made up of cells, and all cells come from preexisting cells.

Spontaneous Generation

The former hypothesis that living organisms could arise spontaneously from nonliving material under certain conditions.

Louis Pasteur's Experiment

An experimental setup comparing straight-necked and swan-necked flasks to test cell theory versus spontaneous generation, demonstrating that cells arise only from preexisting cells.

Common Lineage

The cellular connection demonstrating that all living things and cells in a multicellular organism have descended from preexisting cells.

Theory of Inheritance

Formulated by Sutton and Boveri, stating that hereditary/genetic information is encoded in genes, which are units located on chromosomes.

Chromosome

A structure composed of DNA molecules (identified in the 1950s as hereditary material) containing functional segments called genes.

DNA Structure

A double helix composed of four nucleotide building blocks ($A$, $T$, $C$, and $G$), where $A$ pairs with $T$ and $C$ pairs with $G$.

Central Framework of Molecular Biology

The pathway describing the flow of genetic information in cells: DNA codes for RNA, and RNA codes for proteins.

Messenger RNA (mRNA)

A specialized RNA molecule that is read by cellular machinery to make proteins.

Fundamental Nutritional Needs

The two basic requirements of all organisms: acquiring chemical energy in the form of ATP and acquiring building blocks to synthesize DNA, RNA, and proteins.

Descent with Modification

Darwin's description of evolution stating that species are related by common ancestry and their characteristics can be modified from generation to generation.

Population

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

Natural Selection

The mechanism of evolution requiring that individuals vary in heritable characteristics and that specific versions of these traits enhance reproductive success in a given environment.

Speciation

The evolutionary process that occurs when populations diverge to form new species.

Fitness

The ability of an individual to produce surviving offspring relative to other individuals in the population.

Adaptation

A heritable trait that increases the fitness of an individual in a particular environment.

Tree of Life

A family tree depicting evolutionary history and genealogical relationships among species starting from a single ancestral species.

Phylogeny

The actual genealogical relationships among all organisms.

Phylogenetic Tree

A diagram showing relationships between species, where branches sharing a recent common ancestor represent closely related species.

Eukaryotes

Organisms belonging to the domain Eukarya whose cells contain a distinct nucleus.

Prokaryotes

Organisms belonging to the domains Bacteria and Archaea whose cells lack a nucleus.

Linnaeus' Taxonomic System

A classification system established in 1735 by Carolus Linnaeus that gives each organism a unique two-part scientific name consisting of genus and species.

Genus

A taxonomic rank made up of a closely related group of species.

Species

Individuals that regularly breed together, or individuals whose characteristics are distinct from those of other species.

Hypothesis

A testable statement that explains something observed in science.

Prediction

A measurable or observable result expected from an experiment.