This paper aims to provide empirical evidence about concept diversity in the life sciences in relation to levels of text specialization. This paper deals with the terms clone and cloning in science popularization texts about mammals cloning. Texts are in Spanish, were published in scientific journals in Argentina, and show different specialization levels. We show that the terms clone and cloning appear most frequently in less specialized texts, while in more specialized ones they are replaced by the more precise concept nuclear transfer which refers to the technique employed. Furthermore we find a relation between terms use and text parts and segments. For example, the terms clone and cloning appear in headlines and abstracts in highly specialized texts, while they have low frequency in other texts segments. Results confirm the need to study terms in relation to texts. © 2000 John Benjamins Publishing Co.