Learning items
Explore shared ideas across books.
Science & nature
ConceptArtificial selection
Artificial selection is selective breeding in which people influence which organisms reproduce.
ConceptSelf-organization and hierarchy
Systems can develop new organization within interacting levels.
ConceptNegative feedback
A feedback response counteracts a deviation or change.
ConceptRegulated cell cycle
Cells coordinate DNA replication and division through regulatory controls.
ConceptCosmic scale
Cosmic scale concerns the very different sizes, distances and times encountered in astronomy.
VocabularyATP in cellular work
ATP couples energy-releasing processes to energy-requiring cellular work.
ConceptGene expression
Cells use genetic information to produce functional RNA and, for many genes, proteins.
ConceptHomeostasis
Physiological regulation keeps important internal conditions within workable ranges.
VocabularyPhoton
A quantum of the electromagnetic field.
ConceptElliptical orbit
In an ideal bound two-body Kepler orbit, the path is an ellipse with the attracting body at one focus in the usual relative-coordinate description.
VocabularyLight-year
A light-year is the distance light travels in a vacuum in one year.
ConceptEvaporation and cooling
Escaping molecules can remove energy from a liquid.
ConceptAtomic hypothesis
Matter's large-scale behavior can be explained through particles and their interactions.
ConceptCell compartmentalization
Membranes separate cellular environments and organize different tasks.
ConceptLeptons
Elementary particles that do not experience the strong interaction.
All items includes definitions still awaiting topic classification.