[person - cells, genetics & inheritance] (aka Karl Wilhelm von Nägeli) Swiss botanist who studied cell division and pollination (1817 - 1891). Nageli was a prolific author, writing many technical papers and several books, including A mechanico-physiological theory of organic evolution, published in 1884. Despite the fact that this book discusses inherited characteristics, it makes no mention of Mendel's work, and he is often criticized for its absence.

• Appears in modules:

• Mendel and Inheritance

[acronym - planetary science, space exploration] The National Aeronautics and Space Administration, a US government office established in 1958 to research flight in the Earth's atmosphere and beyond.

• Appears in modules:

• Confidence Intervals
• Description in Scientific Research
• Ellen Ochoa
• Factors that Control Earth's Temperature
• France Anne-Dominic Córdova
• Franklin Chang Díaz
• History of Earth's Atmosphere I
• Kevin Arrigo
• Origins of Life II
• Scientific Institutions and Societies
• The How and Why of Scientific Meetings
• The Practice of Science
• Unit Conversion

[organization - atmospheric science] A research center focused on the study of Earth's atmosphere and the physical, biological, and social processes that interact with the atmosphere. NCAR is funded primarily by the National Science Foundation, and provides a variety of resources for the atmospheric sciences community.

[organization - atmospheric science, oceanography] A scientific agency within the United States government that deals with weather monitoring and forecasting, climate and ocean science, management of fisheries and marine commerce, and coastal restoration, among other things. NOAA was formed in 1970 by combining several existing agencies, including the US Coast and Geodetic Survey (established in 1807) and the Weather Bureau (established in 1870). More information about NOAA can be found on their website: http://www.noaa.gov/

• Appears in modules:

• Measurement

[organization - science & decision making, science communication] A United States government agency that supports fundamental research and education in all the non-medical fields of science and engineering.

• Appears in modules:

• France Anne-Dominic Córdova
• Scientific Institutions and Societies
• The How and Why of Scientific Meetings
• Using Graphs and Visual Data in Science

[noun] The sciences dealing with the study of all objects in nature; used more commonly in the 18th and 19th centuries to refer to early studies in biology and geology but still in use today. Natural history generally consists of observing natural systems rather than performing experiments. Those who study natural history are called naturalists or natural historians.

• Appears in modules:

• Animal Behavior
• Charles Darwin I
• Charles Darwin III
• Experimentation in Scientific Research
• Scientists and the Scientific Community
• Taxonomy I
• Taxonomy II

[noun - hydrology & fresh water, rocks & minerals, energy resources, environmental policy, human impacts on the environment, natural resources, nutrient cycles] Materials produced through or contained within Earth's natural systems and used by humans and other species. They include minerals and soil, water, air, and various plant and animal species (such as trees cut for wood, fish eaten for protein, and bees that pollinate plants).

• Appears in modules:

• Biodiversity I
• The Silicate Minerals

[noun - evolution & adaptation, genetics & inheritance] The process whereby characteristics that promote survival and reproduction are passed on to future generations, so these characteristics become more frequent in the population over time.

• Appears in modules:

• Adaptation
• Animal Behavior
• Biodiversity I
• Charles Darwin I
• Charles Darwin II
• Charles Darwin III
• Future of Human Evolution
• Origins of Life I
• Origins of Life II
• Population Genetics
• Taxonomy I
• Theories, Hypotheses, and Laws
• Y-Chromsome and Mitochondrial DNA Haplotypes

[acronym - atmospheric science] National Center for Atmospheric Research

• Appears in modules:

• Scientific Controversy

[noun - evolution & adaptation, taxonomy & systematics] An extinct species of humans, Homo neanderthalensis, who lived from approximately 400,000 to 40,000 years ago

• Appears in modules:

• Charles Darwin I
• Introduction to Paleoanthropology
• The Piltdown Hoax
• Y-Chromsome and Mitochondrial DNA Haplotypes

[noun - stellar and galactic astronomy] A nebula (singular) is a cloud of interstellar matter, mainly dust and gases. Nebulae (plural) are numerous nebula that form a cluster, such as a galaxy. Nebulae are the birthplace of stars, with rare exceptions.

• Appears in modules:

• History of Earth's Atmosphere I
• The Nature of Scientific Knowledge

[noun - scientific tools & techniques, research methods] In science, a negative control refers to a system that is identical to a treatment in all ways with the specific exception of the treatment itself. Thus, the negative control provides a measure of the natural fluctuations of a dependent variable due to factors other than the experimental treatment. For more information, see our module Experimentation in Scientific Research.

• Appears in modules:

• Experimentation in Scientific Research

[noun - biomolecules, cells, chemical reactions, organic & biochemistry] Net movement occurs when molecules move from a region of higher concentration to a region of lower concentration due to random molecular motion.

• Appears in modules:

• Membranes II

[noun] An interconnected system; an interrelated net-like arrangement of parts.

• Appears in modules:

• Animal Behavior
• Cell Division I
• Cellular Organelles I
• Chemical Bonding
• Composition of Earth's Atmosphere
• Data Analysis and Interpretation
• Earth Structure
• Linear Equations in Science
• Origins of Life I
• Peer Review in Scientific Publishing
• Properties of Solids
• Santiago Ramón y Cajal and Camillo Golgi
• Scientific Institutions and Societies
• Sergio Avila
• Utilizing the Scientific Literature
• Water

[adjective - scientific tools & techniques, research methods] Generally defined as neither one thing nor another. 1. Electrically neutral refers to having no net electrical charge, usually achieved by having an equal number of positive and negative charges, atoms are electrically neutral. 2. In acid/base chemistry, neutral refers to a solution that is neither acid nor base. A neutral solution contains equal concentrations of H⁺ and OH^-, and has a pH = 7.

• Appears in modules:

• Acids and Bases I
• Acids and Bases II
• Atomic Theory II

[noun - chemical reactions, scientific tools & techniques, research methods] The chemical process of making a solution of acid or base into a neutral solution by adding either base or acid, respectively. A process represented by the reaction: Acid + Base --> H₂O + Salt

• Appears in modules:

• Chemical Reactions

[noun - atoms & subatomic particles, atoms & subatomic particles] A sub-atomic particle with no charge and a mass of 1.675 × 10^-27 kg. Neutrons are found in the nucleus of atoms. Compare to proton and electron.

• Appears in modules:

• Atomic Theory II
• Energy
• France Anne-Dominic Córdova
• History of Earth's Atmosphere II
• Luis Walter Alvarez
• Meselson and Stahl
• Nuclear Chemistry
• Scientific Ethics

[noun - cells] The most abundant type of white blood cell in vertebrates.

[noun - units of measurement, forces] A metric (or SI) unit measuring force and named for English physicist Isaac Newton. One newton (N) represents the force needed to accelerate a one-kilogram (kg) object 1 meter (m) per second (s) per second (s): N = kg·m/s².

• Appears in modules:

• Atomic Theory II
• Charles Darwin II
• Chemical Bonding
• Defining Minerals
• Description in Scientific Research
• Earth Structure
• Energy
• Experimentation in Scientific Research
• Gravity
• Light I
• Scientific Institutions and Societies
• The Practice of Science
• Theories, Hypotheses, and Laws
• Understanding Scientific Journals and Articles
• Unit Conversion
• Using Graphs and Visual Data in Science
• Utilizing the Scientific Literature
• Waves and Wave Motion

[person - medicine] English nurse and statistician born in Florence, Italy (1820-1910). Nightingale observed that poor sanitation was the leading cause of deaths in field hospitals during the Crimean War, and became a key activist for hospital sanitation. She was a skilled statistician, and used statistical observations to convince the Members of Parliament of the medical conditions during the Crimean War. Nightingale was also extremely influential in the field of nursing: the Nightingale School of Nursing still teaches her care-giving principles.

[noun - chemical reactions] The oxidation (as by bacteria) of ammonium salts to nitrites and the further oxidation of nitrites to nitrates.

• Appears in modules:

• The Nitrogen Cycle

[noun - chemical reactions, atmospheric science, nutrient cycles] The assimilation of atmospheric nitrogen into ammonia, most commonly through metabolic processes of soil microorganisms. Other agents of nitrogen fixation include lightning,forest fires, and the industrial process used to manufacture synthetic fertilizers.

• Appears in modules:

• The Nitrogen Cycle

[acronym - atmospheric science, oceanography] National Oceanic and Atmospheric Administration

• Appears in modules:

• Craig Lee
• Factors that Control Regional Climate

[noun - science communication] Awards made annually, beginning in 1901, from funds originally established by Alfred B. Nobel for outstanding achievement in physics, chemistry, medicine or physiology, literature, and the promotion of peace. A Nobel Prize in economics was established from private funds in 1969.

• Appears in modules:

• Atomic Theory I
• Atomic Theory II
• Atomic Theory III
• Barbara McClintock
• Bernardo Houssay
• Carlos J. Finlay
• Cell Division I
• Cell Division II
• César Milstein
• Chemical Bonding
• Creativity in Science
• DNA II
• DNA III
• Energy Metabolism I
• Gene Expression
• History of Earth's Atmosphere I
• Luis E. Miramontes
• Luis Walter Alvarez
• Mario Molina
• Membranes I
• Nuclear Chemistry
• Percy Lavon Julian
• Ruth Benerito
• Santiago Ramón y Cajal and Camillo Golgi
• Scientists and the Scientific Community
• The Practice of Science
• The Silicate Minerals

[noun - taxonomy & systematics] A formal naming system.

[adjective - atoms & subatomic particles, atoms & subatomic particles] A physical system where relativistic effects (those involving the theory of relativity) are small enough to be ignored. Usually, this is a system in which nothing is traveling faster than around one percent of the speed of light (aka, c), such as the electron in a hydrogen atom.

• Appears in modules:

• Atomic Theory III

[noun - atoms & subatomic particles, chemical reactions, physical & chemical properties] A covalent bond in which electrons are equally shared between bonding atoms. A nonpolar covalent bond is formed when both atoms participating in a bond have an equal or nearly equal affinity for electrons (electronegativity). A nonpolar bond will result in a symmetric distribution of electron charge across the bonding pair. Compare to polar covalent molecule.

• Appears in modules:

• Properties of Liquids

[noun - atoms & subatomic particles, chemical reactions, physical & chemical properties] A molecule that has an equal distribution of bonding electrons across it and possesses no partial positive or negative charges. Nonpolar molecules are formed by nonpolar covalent bonds or when polar covalent bonds result in a symmetric distribution of electrical charge, the configuration + - - + for example. Compare to polar covalent molecule.

• Appears in modules:

• Properties of Liquids

[noun - statistics, data] Also called a Gaussian distribution or a bell curve, the normal distribution is one of a family of continuous probability distributions in which the probability of observing any specific value is evenly distributed about the mean (µ) of the dataset and falls off continuously as one moves away from the mean value in either direction. The standard deviation (σ) of the dataset describes the spread of a normally distributed set of data as seen in the figure:

• Appears in modules:

• Confidence Intervals
• Introduction to Descriptive Statistics

[verb - anatomy & physiology, nutrition, organisms, biodiversity & ecological relationships, energy resources, natural resources, nutrient cycles, organisms] The act of providing an organism with nutrients.

• Appears in modules:

• The Nitrogen Cycle
• The Phosphorus Cycle

[acronym - science communication] National Science Foundation.

• Appears in modules:

• France Anne-Dominic Córdova
• Scientific Institutions and Societies

[noun - atoms & subatomic particles] A reaction in which an atom's nucleus splits into smaller parts, releasing a large amount of energy in the process. Most commonly this is done by "firing" a neutron at the nucleus of an atom.

• Appears in modules:

• Exponential Equations in Science I
• Franklin Chang Díaz

[noun] A reaction in which different elements are fused together to blend into a larger element, releasing large amounts of energy.

• Appears in modules:

• Factors that Control Earth's Temperature
• Franklin Chang Díaz
• Scientific Ethics

[noun - biomolecules, genetics & inheritance] A group of polymers made of repeating units of phosphoric acid and sugar to which nucleotide bases are attached. The two most common examples are DNA and RNA.

• Appears in modules:

• DNA II

[noun - biomolecules, genetics & inheritance] The building blocks of DNA and RNA, consisting of a nitrogen base, a five-carbon sugar, and one or more phosphate groups.

• Appears in modules:

• Cell Division II
• Cellular Organelles I
• DNA I
• DNA II
• DNA III
• Meselson and Stahl
• The Practice of Science

[noun - cells, atoms & subatomic particles] 1. [Atomic] A tiny, dense positively charged mass at the heart of an atom. The nucleus is composed of protons and neutrons, and contains nearly all of the mass of the atom while occupying only a tiny fraction of the volume. 2. [Cellular] A generally spherical structure encased in a double membrane that is found in most living eukaryotic cells. The nucleus contains hereditary information and directs the growth, metabolism, reproduction, and functioning of the cell.

• Appears in modules:

• Atomic Theory I
• Atomic Theory II
• Atomic Theory IV
• Barbara McClintock
• Cell Division I
• Cell Division II
• Cellular Organelles I
• Chemical Bonding
• Comparison in Scientific Research
• Creativity in Science
• Discovery and Structure of Cells
• DNA II
• Earth Structure
• Energy
• Factors that Control Earth's Temperature
• Franklin Chang Díaz
• History of Earth's Atmosphere I
• Luis Walter Alvarez
• Membranes I
• Modeling in Scientific Research
• Nuclear Chemistry
• Properties of Liquids
• Scientific Controversy
• The Nature of Scientific Knowledge
• The Periodic Table of Elements
• Thermodynamics I

[noun - scientific tools & techniques, research methods] In statistical testing, a null hypothesis (H₀) commonly takes the form of a statement suggesting that an observed result or effect is due to random chance. The null hypothesis is put forward as the counterpart to an alternative hypothesis (H₁), and is presumed correct until statistical testing shows otherwise. For example, in an evaluation of data regarding the pain relieving properties of a new drug, the null hypothesis would state that the new drug has no effect beyond that of a control. The null hypothesis is never proven by statistical testing; either H₁ is accepted in favor of H₀, or H₀ is "not rejected."

• Appears in modules:

• Introduction to Inferential Statistics
• The Case of the Ivory-billed Woodpecker

[noun - ethics, science & decision making] Officially United States of America v. Karl Brandt, et al., was the first of the Trials of War Criminals held before US military court in the aftermath of World War II. Twenty of the defendants were medical doctors and three were Nazi officials who were all accused of having been involved in Nazi human experimentation. Of the 23 defendants, seven were acquitted and seven received death sentences; the remainder received prison sentences ranging from 10 years to life imprisonment.

• Appears in modules:

• Scientific Ethics

[noun - biomolecules, nutrition, atoms & subatomic particles, compounds, elements, organic & biochemistry, physical & chemical properties, energy resources, natural resources, nutrient cycles, organisms] A chemical substance (e.g., minerals, vitamins, proteins) that is needed by an organism to survive and grow. See also: macronutrient and micronutrient.

• Appears in modules:

• Animal Behavior
• Biodiversity I
• Cell Division I
• Cellular Organelles I
• Composition of Earth's Atmosphere
• Diffusion I
• Discovery and Structure of Cells
• Experimentation in Scientific Research
• Gene Expression
• Kevin Arrigo
• Modeling in Scientific Research
• Stoichiometry
• The Nitrogen Cycle
• The Phosphorus Cycle

[noun - nutrition, hydrology & fresh water, oceanography, rock cycle, energy resources, human impacts on the environment, natural resources, nutrient cycles] A sudden increase of nutrients in a given area. Nutrient influxes result in an increase in plant growth. For example, excess fertilizer applied to a farm will leach into nearby streams and rivers. Plants in those water bodies will absorb those nutrients quickly and reproduce. See also: eutrophication.