It is the process of classification of an analyte or a group of analytes from a sample according to physical (e.g. size, solubility) or chemical (e.g. bonding, reactivity) properties.

It refers to the chemical reaction (or reaction sequence) in which one or more new elements of chirality are formed in a substrate molecule and which produces the stereoisomeric (enantiomeric or diastereoisomeric) products in unequal amounts.

It is skin reaction resulting from a single or multiple exposure to a physical or chemical entity at the same site, characterized by the presence of inflammation; it may result in cell death.

It refers to adverse change in the chemical and biological status of a body of water following depletion of the oxygen content caused by decay of organic matter resulting from high primary production as a result of enhanced input of nutrients.

GM products, and GM plants in particular, will have a positive impact on the environment by reducing agricultural chemical use and by promoting good agricultural practices such as no-till agriculture.
These crops could effect the environment through
1) transfer of the GM traits to other plants
2) harm to non-target species
3) increased resistance to commonly used insecticides and herbicides