Principles of Life and Evolutionary Processes

Exactly 50 vocabulary-style flashcards based on lecture notes covering the principles of life, chemical foundations, and evolutionary processes.

Biology

The scientific study of living things or organisms.

organism

Any individual living entity.

single common ancestor

The shared ancestral cell from which all modern life descended.

nucleic acid

Molecules (DNA/RNA) storing and transmitting genetic data using a nearly universal code.

prokaryote

An organism that lacks a nucleus and organelles.

eukaryote

An organism that contains a membrane-enclosed nucleus and organelles.

photosynthesis

A metabolic process converting environmental light energy into chemical energy.

cyanobacteria

Early photosynthetic prokaryotes that oxygenated Earth's atmosphere.

stromatolites

Layered rock structures formed by fossilized mats of cyanobacteria.

aerobic metabolism

A process that uses oxygen ($O_2$) to extract energy from molecules.

anaerobic metabolism

A process that does not use oxygen to extract energy from molecules.

endosymbiosis

Theory that eukaryotic organelles (mitochondria/chloroplasts) evolved from engulfed prokaryotes.

organelle

Any membrane-enclosed internal compartment within a cell.

nucleus

A membrane-bound eukaryotic organelle containing genetic information (DNA).

mitochondria

The eukaryotic organelle executing aerobic metabolism to produce cellular energy (ATP).

chloroplast

The plant organelle containing chlorophyll; the site of photosynthesis.

genome

The complete set of genetic information (DNA) in an organism.

mutation

A permanent alteration in the structural sequence of genetic information.

binomial nomenclature

The two-part scientific naming system consisting of Genus and species.

phylogenetic tree

A diagrammatic reconstruction of evolutionary histories and relationships.

model biological system

Representative species studied in labs to extend findings to general principles (e.g., E. coli).

Ozone ($O_3$)

Molecules in the atmosphere that absorb harmful ultraviolet (UV) radiation from the sun.

tissue

A assembly of similar cells that perform a specific function.

organ

A functional unit formed by the assembly of different tissues.

organ system

A group of organs working together to perform specific body functions.

population

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

ecological community

A collection of interacting species in a specific environment.

biosphere

The sum of all life on Earth and the environments they inhabit.

negative feedback

A control mechanism that slows or stabilizes a process to maintain baseline conditions (homeostasis).

positive feedback

A control mechanism that accelerates or amplifies a process away from the baseline.

gene

A specific segment of DNA that contains instructions for encoding a functional protein or RNA molecule.

evolution

Changes in allele frequencies in a population over time.

natural selection

Differential survival and reproduction of individuals based on heritable traits.

adaptation

A heritable trait that increases an organism's chances of surviving and reproducing in its environment.

hypothesis

A tentative, testable prediction used in scientific inquiry.

theory

A vast, rigorously validated body of principles explaining a major natural phenomenon.

natural history

The purely observational study of organisms in their wild environments without manipulative testing.

controlled experiment

An experiment where subjects are divided into a treatment group and a control group receiving no treatment.

independent variable

The specific factor manipulated by a scientist during an experiment.

dependent variable

The response or outcome measured by a scientist in an experiment.

atom

The fundamental, smallest unit of matter retaining chemical properties.

element

A fundamental pure substance consisting of only one kind of atom.

isotope

Variants of an element with the same number of protons but different numbers of neutrons.

electronegativity

The attractive pull an atom's nucleus exerts on shared electrons in a bond.

covalent bond

A chemical bond involving the sharing of electron pairs between atoms.

ionic bond

Electrostatic attractions between a positive cation and a negative anion.

entropy

A thermodynamic measure of randomness or disorder in a system.

amphipathic

A molecule possessing both polar (hydrophilic) and non-polar (hydrophobic) regions.

gene flow

The movement of alleles between different populations via migration or gamete transfer.

genetic drift

Random fluctuations in allele frequencies from generation to generation due to chance events.