Biology Notes: Organization of Life, Emergent Properties, and Evolution

Vocabulary flashcards covering key concepts from biological organization, emergent properties, scientific methods, DNA, and evolution.

Atom

The simplest building block of all matter and living things; the basic unit of a chemical element.

Molecule

A stable group of two or more atoms bonded together; building block for larger structures.

Macromolecule

A very large, complex molecule (such as proteins or nucleic acids) formed by linking smaller subunits.

Organelle

A specialized subunit within a cell that performs a specific function.

Cell

The basic unit of life; the smallest unit capable of carrying out all life processes.

Tissue

A group of similar cells performing a common function.

Organ

A structure composed of tissues that carries out a specific function.

Organ system

A group of organs working together to perform major bodily functions.

Organism

An individual living thing.

Population

A group of individuals of the same species living in a particular area; analyzes how organisms interact.

Species

A group of organisms capable of interbreeding and producing fertile offspring; genetically similar.

Emergent properties

New characteristics that arise when components interact to form a system; not present in individual parts.

Reductionism

An approach that explains complex systems by studying their simpler parts; may overlook system-level properties.

DNA

Deoxyribonucleic acid; molecule that stores genetic information.

Nucleotide bases

The four building blocks of DNA—adenine, thymine, cytosine, and guanine.

Hypothesis-based science

Science that starts with a testable question, proposes a hypothesis, and tests it with experiments.

Descriptive science

Observational science that describes phenomena and patterns, often without a prior hypothesis.

Pasteur

Louis Pasteur; scientist who showed microbes cause contamination and developed pasteurization.

Pasteurization

Heating liquids to kill microbes and reduce contamination.

Nutrient broth

A nutrient-rich liquid medium used to culture microbes in experiments.

Sterilization

Process of killing all microorganisms to render a material free of life.

Swan-neck flask

Pasteur’s curved-neck container that prevents airborne microbes from entering the broth, eliminating the idea that air alone causes contamination.

Variable (in an experiment)

A factor that can affect the results of an experiment.

Independent variable

The variable deliberately changed by the experimenter to test its effect.

Control variable

A variable kept constant to ensure a fair test.

Fossil record

Evidence of historical life preserved in fossils, used to study evolution.

Darwin’s finches

Finches on the Galápagos Islands showing variation in beaks and traits linked to local resources, illustrating evolution.

Descent with modification

The principle that species arise from ancestral forms through heritable changes over generations.

Variation

Differences among individuals in a population that can influence survival and reproduction.

Natural selection

Differential survival and reproduction of individuals due to trait variation, leading to evolutionary change.

Phylogenetic tree

A diagram showing evolutionary relationships among species, often based on DNA differences.

Convergent evolution

Independent evolution of similar traits in different lineages due to similar selective pressures.

Analogous structures

Structures with similar function and appearance but different evolutionary origins.