| Term | Definition | | Natural language processing (NLP) | NLP is the process through which AI is taught to understand the rules and syntax of language, programmed to develop complex algorithms to represent those rules, and then made to use those algorithms to carry out specific tasks, like language generation, translation, and summarization. |
| Natural Selection | Natural selection is a fundamental mechanism of evolution where organisms better adapted to their environment tend to survive and produce more offspring. Proposed by Charles Darwin, this process drives species change over time by passing on advantageous, heritable traits. |
| Neural network | A neural network is a kind of computer algorithm modeled off the human brain, and it's typically created using machine learning or deep learning. Neural networks can approximate complex functions without being programmed directly, and they're at the core of most modern AI models. |
| Nitrogen Cycle | The natural circulation of nitrogen among the atmosphere, plants, animals, and microorganisms that live in soil and water. Nitrogen takes on a variety of chemical forms throughout the nitrogen cycle, including nitrous oxide and nitrogen oxides. |
| Nitrous Oxide (N2O) | A powerful greenhouse gas with a global warming potential of 298 times that of carbon dioxide (CO2). Major sources of nitrous oxide include soil cultivation practices, especially the use of commercial and organic fertilizers, fossil fuel combustion, nitric acid production, and biomass burning. |
| Non-Linear Relationship | When a given increase in one variable (x, or the independent variable) does not always correspond to a constant increase in the other variable (y, or the dependent variable), for all possible values of x. The graph of this relationship will be a curve instead of a straight line (as is the case in linear relationships). |
| Nucleotide | The basic structure of nucleic acids (DNA and RNA) that, when linked together, form the building blocks of DNA or RNA. They are composed of a phosphate group, a nitrogenous base, and a sugar (deoxyribose or ribose). For all types of living organisms, there are four types of bases in DNA: adenine (A), guanine (G), cytosine (C) and thymine (T). Thymine is replaced by Uracil (U) in RNA. |
| Nucleus | The organelle of a plant or animal cell that contains the genetic information (DNA). A bacteria cell does not have a nucleus. |
| Ocean Acidification | Increased concentrations of carbon dioxide in sea water causing a measurable increase in acidity (i.e., a reduction in ocean pH). This may lead to reduced calcification rates of calcifying organisms such as corals, mollusks, algae and crustaceans. |
| Outlier | A data point in a set of data that is much bigger or much smaller than the rest of the set. |
