Preserved remains of once-living plants or animals in which the replacement of organic or inorganic materials bysoil minerals has begun. Naturally occurring casts are also ...
The process of regulated growth that results from the interaction of the genome with cytoplasm and the environment. It involves a programmed sequence of phenotypic events that are ...
1. A violently rotating column of air, in contact with the ground, either pendant from a cumuliform cloud or underneath a cumuliform cloud, and often ...
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