[noun - rocks & minerals] A dark-colored intrusive igneous rock that consists mostly of the minerals plagioclase, pyroxene, and olivine. Gabbro has a similar composition to basalt, which is extrusive. Both gabbro and basalt are mafic rocks, composed of minerals high in iron and magnesium.

• Appears in modules:

• The Rock Cycle

[person - planetary science, research tools, solar and lunar processes, laws & theories, scientific tools & techniques, research methods, science & decision making, scientific concepts] The Italian physicist, mathematician, and astronomer born in Pisa in the Grand Duchy of Tuscany (1564-1642 CE). Among other things, Galileo studied the acceleration of objects and discovered the four largest moons of the planet Jupiter. His work significantly advanced the use of quantitative experimentation in science, and he made noteworthy contributions in the development of technology: He invented the refracting telescope, perfected the compound microscope, and improved compass design. Galileo was famously jailed during the Inquisition for his support of Copernicus's heliocentric view of the cosmos.

• Appears in modules:

• Factors that Control Regional Climate
• Gravity
• Scientific Institutions and Societies
• Temperature
• The Practice of Science
• Utilizing the Scientific Literature
• Water
• Waves and Wave Motion

[noun - anatomy & physiology, cells, genetics & inheritance, organisms] A reproductive cell having half the number of chromosomes (a haploid) of a mature cell, e.g., a sperm or egg cell.

• Appears in modules:

• Mendel and Inheritance

[noun - matter, physical & chemical properties, matter] The state of matter characterized by its non-condensed nature and ability to flow. Unlike liquids, molecules within a gas remain far apart from each other and show little interaction with other molecules. Unlike solids, gases do not have fixed shapes and take the shape of their container (as do liquids). Compare with liquid and solid.

• Appears in modules:

• Atomic Theory I
• Atomic Theory II
• Carbon Chemistry
• Cellular Organelles I
• Chemical Bonding
• Chemical Reactions
• Comparison in Scientific Research
• Composition of Earth's Atmosphere
• Data Analysis and Interpretation
• Diffusion I
• Early Ideas about Matter
• Energy Metabolism I
• Factors that Control Earth's Temperature
• Factors that Control Regional Climate
• Franklin Chang Díaz
• History of Earth's Atmosphere I
• History of Earth's Atmosphere II
• Introduction to Descriptive Statistics
• Kinetic-Molecular Theory
• Louis Tompkins Wright
• Mario Molina
• Membranes I
• Nuclear Chemistry
• Origins of Life I
• Photosynthesis I
• Properties of Gases
• Properties of Liquids
• Scientific Institutions and Societies
• Solutions, Solubility, and Colligative Properties
• States of Matter
• Stoichiometry
• The Carbon Cycle
• The Hydrologic Cycle
• The Mole and Atomic Mass
• The Nitrogen Cycle
• Thermodynamics I
• Unit Conversion
• Water

[noun - matter, physical & chemical properties, matter] A physical constant used in the ideal gas equation to relate a gas’s state to its pressure, volume, amount, and temperature. Given the symbol R, it was first defined by the German chemist August Horstmann in 1873.

[noun - matter, physical & chemical properties, matter, thermodynamics] A set of observed relationships between a gas’s pressure, absolute temperature, volume, and amount. The gas laws consist of Avogadro’s Law, Boyle’s Law, and Charles’s Law.

• Appears in modules:

• Kinetic-Molecular Theory

[noun - biomolecules, cells] Active ion channels can regulate the passage of ions via a gate mechanism. Gates can open (allow ions to flow through) or close (restrict the flow of ions) depending on external signals. This property of permitting and restricting ion flow is called "gating."

• Appears in modules:

• Membranes II

[person - statistics] German mathematician born in Brunswick, Germany (1777 – 1885 CE). Sometimes called the “prince of mathematics,” Gauss made important contributions to many fields of mathematics and science. In his major 1809 work Theoria motus corporum coelestium, Gauss presented several mathematical approaches for addressing the experimental measurement errors that plagued astronomers of the time. These included the method of least squares and a mathematical derivation of the normal distribution.

• Appears in modules:

• Introduction to Descriptive Statistics

[noun - equations, statistics] See normal distribution.

• Appears in modules:

• Introduction to Descriptive Statistics

[person - matter, physical & chemical properties, matter, thermodynamics] A French physicist and chemist, born in Saint-Léonard-de-Noblat, France (1778 – 1850). Gay-Lussac performed extensive research into gases, which influenced the work of the Italian chemist Amedeo Avogadro and the development of Charles’s Law after the French scientist Jacques-Alexandre-César Charles.

• Appears in modules:

• Properties of Gases
• The Mole and Atomic Mass

[acronym - atmospheric science, weather & climate] See
General Circulation Model.

• Appears in modules:

• Modeling in Scientific Research

[noun - biomolecules, cells, genetics & inheritance] Material (usually DNA) that is inherited from a parent and which encodes for a cellular component important for some cellular function.

• Appears in modules:

• Animal Behavior
• Barbara McClintock
• Bernardo Houssay
• Cell Division II
• Cellular Organelles I
• César Milstein
• Charles Darwin III
• Creativity in Science
• David Ho
• DNA III
• Fabiola León-Velarde
• Gene Expression
• Mendel and Inheritance
• Theories, Hypotheses, and Laws
• Y-Chromsome and Mitochondrial DNA Haplotypes

[noun - genetics & inheritance] The intentional use of any technique to expand, or drive, particular genes and their associated traits through a population of sexually-reproducing organisms. This results in the particular genes being passed to offspring at rates higher than what Mendelian laws would predict.

• Appears in modules:

• Future of Human Evolution

[noun - atmospheric science, weather & climate, weather & climate] Also referred to as General Climate Models; a class of computer models used for weather forecasting and understanding or projecting climate change. GCMs designed for applications with the scope of decades to centuries were originally created by Syukuro Manabe and Kirk Bryan at the Geophysical Fluid Dynamics Laboratory in Princeton, New Jersey. For more information, see our module Modeling in Scientific Research.

• Appears in modules:

• Modeling in Scientific Research

[noun - genetics & inheritance, evolution & adaptation] Offspring at the same step in the line of descent from a common ancestor.

• Appears in modules:

• Adaptation
• Animal Behavior
• Cell Division I
• Cell Division II
• Cellular Organelles I
• César Milstein
• Charles Darwin II
• Charles Darwin III
• Creativity in Science
• DNA I
• DNA III
• Experimentation in Scientific Research
• Franklin Chang Díaz
• Future of Human Evolution
• Gene Expression
• Introduction to Descriptive Statistics
• Introduction to Inferential Statistics
• Mendel and Independent Assortment
• Mendel and Inheritance
• Meselson and Stahl
• Origins of Life I
• Origins of Life II
• Population Genetics
• Taxonomy I
• The Practice of Science
• Theories, Hypotheses, and Laws
• Y-Chromsome and Mitochondrial DNA Haplotypes

[noun - evolution & adaptation, genetics & inheritance] Changes in gene frequencies due to random events, such as when a small group is isolated from the rest of the population, thus narrowing the gene pool.

• Appears in modules:

• Future of Human Evolution
• Population Genetics
• Y-Chromsome and Mitochondrial DNA Haplotypes

[noun - genetics & inheritance] All of the genetic material of an organism, carried in its DNA.

• Appears in modules:

• Barbara McClintock
• Cellular Organelles I
• Data Analysis and Interpretation
• David Ho
• Future of Human Evolution
• Introduction to Paleoanthropology
• Scientific Controversy
• Y-Chromsome and Mitochondrial DNA Haplotypes

[noun - evolution & adaptation, genetics & inheritance, organisms] The genetic makeup of an organism or group of organisms; the genetic description of an individual. Genotype may refer to a single gene, a set of genes, or the entire genetic makeup of an individual.

• Appears in modules:

• Animal Behavior
• Mendel and Independent Assortment
• Mendel and Inheritance

[noun - evolution & adaptation, taxonomy & systematics] (plural: genera) A taxonomic category one rank or step above species in the Linnaean system, and which may include one or many species in it.

• Appears in modules:

• Barbara McClintock
• Cell Division II
• Charles Darwin III
• Energy
• Franklin Chang Díaz
• Introduction to Paleoanthropology
• Photosynthesis I
• Scientists and the Scientific Community
• Taxonomy II
• The Nitrogen Cycle
• The Practice of Science
• The Scientific Method
• Theories, Hypotheses, and Laws
• Utilizing the Scientific Literature

[adjective - landforms & geologic formations, rocks & minerals, seismology & plate tectonics] Having or representing the Earth as the center, as in the heliocentric concept of the universe. Compare to heliocentric.

• Appears in modules:

• The Practice of Science

[noun - landforms & geologic formations, environmental policy, human impacts on the environment, natural resources, data, computers & programming, scientific tools & techniques, research methods, science & decision making] (GIS) A set of computer-based tools used to collect, store, analyze, and map data that has a location-based or spatial component, such as latitude and longitude. The term GIS usually includes computer software and hardware, data collectors, and the data itself.

These systems allow researchers and decision makers to compile information from many different sources. By gathering and mapping a wide variety of data, we can see new trends and relationships. Satellite images, records of soil type or vegetation cover, census data, locations of roads and schools, and many other types of data can be compiled in a GIS.

• Appears in modules:

• Sergio Avila

[organization - atmospheric science, landforms & geologic formations, rock cycle, rocks & minerals, seismology & plate tectonics, weather & climate, science communication] A professional society established in 1888 focused on geosciences. The mission of the Geological Society of America is "to be a leader in advancing the geosciences, enhancing the professional growth of its members, and promoting the geosciences in the service to humankind and stewardship of the Earth." GSA hosts an annual meeting and several section meetings every year and publishes several journals. More information about GSA can be found at their website: http://geosociety.org

• Appears in modules:

• The How and Why of Scientific Meetings

[noun - landforms & geologic formations, rock cycle, rocks & minerals, seismology & plate tectonics] The solid portion of Earth, including the crust and mantle.

• Appears in modules:

• Kevin Arrigo
• The Carbon Cycle
• The Nitrogen Cycle

[person - atoms & subatomic particles, modern physics] German physicist noted for his work with Otto Stern in establishing the spin-quantization of electrons.

• Appears in modules:

• Atomic Theory III

[person - landforms & geologic formations, rock cycle, rocks & minerals, seismology & plate tectonics] American geologist born in Rochester, New York (1843-1918). Gilbert participated in the Wheeler geologic survey of the American West. His field studies resulted in the publication on The Geology of the Henry Mountains, which established his preeminence as a geologist. In 1879, he was appointed the Senior Geologist at the newly created US Geological Survey. In addition to his study of the Henry Mountains, Gilbert investigated the Pleistocene Lake Bonneville. He is considered a major founder of the field of geomorphology, having investigated and published on erosion, river incision and sedimentation.

• Appears in modules:

• Description in Scientific Research
• The Practice of Science

[noun - time periods] Any of those parts of geologic time from Precambrian onward when a much larger portion of the Earth was covered by glaciers than at present.

• Appears in modules:

• The Carbon Cycle

[noun - landforms & geologic formations, seismology & plate tectonics, bioregions, biomes & ecosystems, computers & programming, scientific tools & techniques] (GPS) A system of satellites maintained by the US government that provides people with highly accurate information about their location on Earth (within about three meters) and how to navigate from place to place. Users obtain the information (called coordinates) using GPS receivers, such as handheld devices, navigation systems in cars, and programs like Google Maps.

• Appears in modules:

• Craig Lee
• Linear Equations in Science
• Origins of Plate Tectonic Theory

[noun] Terms highlighted in green in the main lesson text are hyperlinked to a pop-up glossary to provide easy access to definitions.

[noun] The primary form of sugar stored in the human body for energy: C₆H₁₂O₆.

• Appears in modules:

• Bernardo Houssay
• Blood Biology I
• Energy Metabolism I
• Energy Metabolism II
• Membranes II
• Photosynthesis I
• Solutions, Solubility, and Colligative Properties

[noun - anatomy & physiology, cells] An organelle in eukaryotic cells responsible for packaging, modifying, and delivering newly formed proteins to their proper destination.

• Appears in modules:

• Cellular Organelles I

[person - evolution & adaptation, organisms, taxonomy & systematics, biodiversity & ecological relationships, organisms] English primatologist and anthropologist, born in London (1934-). Goodall is famous for her ground-breaking 45-year study of chimpanzee family and social interactions in the Gombe Stream National Park, Tanzania. She founded the Jane Goodall Institute and remains a leader in global efforts to protect chimpanzees. Goodall revolutionized the field of primatology by discovering tool-making among wild chimpanzee populations, and remains the only human ever accepted into chimpanzee society. Interestingly, Goodall suffers from prosopagnosia, a neurological condition that makes it difficult for her to recognize human faces.

• Appears in modules:

• Description in Scientific Research
• Experimentation in Scientific Research

[person - science & decision making, science communication, scientific concepts] (1886-1949) An American chemist and science educator. Gordon is most famous for his dedication to communicating science. He founded and was the first editor of the Journal of Chemical Education, published by the American Chemical Society, and established the Gordon Research Conferences, a venue to bring scientists together to discuss research on the frontiers of knowledge.

• Appears in modules:

• The How and Why of Scientific Meetings

[person - statistics] (1876 - 1937) Gosset was a chemist working for the brewery company Guinness and the developer of "Student's t-distribution" tool. Gosset needed a way to select the best varieties of barley to use in Guinness’ beer by analyzing only very small subsamples of data collected from the farm. After studying with Karl Pearson, Gosset developed the Student's t-distribution, a new mathematical tool that could be used to estimate a population mean based on a small subsample.

• Appears in modules:

• Confidence Intervals

[person - evolution & adaptation, organisms, taxonomy & systematics, biodiversity & ecological relationships, ethics, research methods, science & decision making, science communication, scientific concepts] American paleontologist born in New York City, New York (1941-2002). With Niles Eldridge, he co-created and championed the concept of evolution via punctuated equilibrium, and wrote many popular books about evolution, paleontology, and the history of science.

• Appears in modules:

• Theories, Hypotheses, and Laws

[anatomy & physiology, toxicology & pharmacology, atoms & subatomic particles, matter, atoms & subatomic particles, matter] Scottish physical chemist (1805-1869) born in Glasgow. Graham first quantified the principles of diffusion by studying gases passing through plugs, tubes, and small openings. His research resulted in Graham's Law, which states that the rates at which two gases diffuse is inversely proportional to the square root of their densities.

• Appears in modules:

• Diffusion I

[noun - rocks & minerals] A light-colored, coarse-grained igneous rock formed by cooling of silica-rich magma below the surface of the Earth. Granite is considered to be the average composition of the continental crust of the Earth.

• Appears in modules:

• Defining Minerals
• Earth Structure
• Properties of Minerals
• The Silicate Minerals
• Utilizing the Scientific Literature

[noun - forces] The natural force that attracts a body toward the center of the Earth, or toward another physical body having mass.

• Appears in modules:

• Atomic Theory I
• Blood Biology I
• Chemical Bonding
• Earth Structure
• Energy
• Experimentation in Scientific Research
• Factors that Control Regional Climate
• France Anne-Dominic Córdova
• Gravity
• History of Earth's Atmosphere I
• Plates, Plate Boundaries, and Driving Forces
• Properties of Liquids
• Properties of Solids
• Theories, Hypotheses, and Laws
• Water

[noun - energy resources, environmental policy, human impacts on the environment, weather & climate, science & decision making, scientific concepts] The greenhouse effect is created by gases like carbon dioxide in the Earth's atmosphere. Carbon dioxide and other greenhouse gases allow radiation from the sun to pass through the atmosphere; the Earth then absorbs this radiation and emits heat. That heat is absorbed by the greenhouse gases, resulting in atmospheric warming.

• Appears in modules:

• Composition of Earth's Atmosphere
• Factors that Control Earth's Temperature

[noun - atmospheric science, weather & climate, human impacts on the environment, weather & climate] A greenhouse gas is a component of the atmosphere that absorbs heat radiated by the Earth and subsequently warms the atmosphere, creating what is commonly known as the greenhouse effect. Common greenhouse gases include carbon dioxide (CO₂), methane (CH₄), water vapor, and sulfate (SO₄).

[person - genetics & inheritance] (ca. 1879 - 1941) A British microbiologist whose research focused on the epidemiology and pathology of bacterial infectious diseases. In 1928, Griffith published his most famous paper, which contained the first widely accepted demonstrations of bacteria changing form and function. His experiments showed the bacteria Streptococcus pneumoniae transforming from one strain to another. His findings encouraged other researchers to try to identify the mechanism by which this change could occur; eventually this research led to the discovery of DNA.

• Appears in modules:

• DNA I

[noun - atoms & subatomic particles] The lowest energy state for an atom or molecule. When an atom is in its ground state, its electrons fill the lowest energy levels before they begin to occupy higher orbitals.

• Appears in modules:

• Atomic Theory II
• Atomic Theory IV

[landforms & geologic formations, environmental policy, human impacts on the environment, natural resources, computers & programming, scientific tools & techniques, data] [verb] To gather data onsite in order calibrate a model or determine whether information captured remotely (such as imagery or measurements taken by satellite) is being accurately interpreted. This often involves going to a location "on-the-ground" or in the field to compare actual characteristics, such as vegetation cover or temperature readings, with characteristics predicted by a model or interpreted from an image. This technique is commonly used with aerial and satellite imagery, remote sensing, meteorology models, and GIS.

[noun] Data collected at a study site, as opposed to information collected remotely or predicted by a model.

• Appears in modules:

• Sergio Avila

[noun - hydrology & fresh water] Water that fills pore space in rocks and sediments and forms a subsurface aquifer. Groundwater is distinct from soil moisture, which does not completely fill pore spaces and is immediately beneath the surface.

• Appears in modules:

• Modeling in Scientific Research
• The Hydrologic Cycle
• The Nitrogen Cycle
• The Rock Cycle

[noun - elements] A column of elements in the periodic table.

• Appears in modules:

• Animal Behavior
• Data Analysis and Interpretation
• Origins of Life II
• The Periodic Table of Elements

[acronym - atmospheric science, landforms & geologic formations, physical & chemical properties, rocks & minerals, seismology & plate tectonics, weather & climate] Geological Society of America

[person] German geophysicist, born in Darmstadt (1889-1960). Gutenberg is best known for precisely determining the depth to the core of the Earth and describing its elastic properties. He also described the differences in structure of oceanic and continental crust, discovered a low-velocity zone within the mantle, created a magnitude scale for earthquakes, and studied the distribution of temperature in the Earth.

• Appears in modules:

• Earth Structure