Final answer:
The prefixes 'dipl-' and 'diplo-' mean 'double' or 'twice,' as in the term 'diplontic,' which indicates a life cycle dominated by diploid cells, which is the case in humans.
Step-by-step explanation:
The prefixes dipl- and diplo- signify 'double' or 'twice' and are often used in biological terms. When it comes to life cycles, diplontic refers to a life cycle in which the diploid stage is dominant. In diplontic organisms, like humans, the diploid cells are prominent and the life cycle spends most of its time in this stage. In contrast, haplontic life cycles are dominated by haploid cells. Furthermore, a diploblast is an animal that develops from two embryonic layers, and the term diphyodont refers to an organism that develops two sets of teeth over its lifetime.