Final answer:
The term for the number of chromosomes in each somatic cell nucleus of diploid organisms is the diploid number, symbolized as '2n'.
Step-by-step explanation:
For diploid organisms, the specific number of chromosomes found in each somatic cell nucleus is referred to as the diploid number, commonly represented by the symbol 2n. Each somatic cell contains two matched sets of chromosomes, known as homologous chromosomes, with one set inherited from each parent.
For example, in humans, the diploid number is 46, meaning there are 23 pairs of homologous chromosomes in each body cell. These homologous pairs have the same genes in identical locations along their lengths, although they are not identical because they come from different parents.