Final answer:
The statement is false as eukaryotic species show a diversity of life cycles, with some being haploid, some diploid, and others showing an alternation of generations, where neither haploid nor diploid is the exclusive phase.
Step-by-step explanation:
The statement 'Most eukaryotic species are haploid or have such a phase to their life cycle' is false. In eukaryotes, we observe diverse life cycles, which can include haploid life cycles, haploid-dominant life cycles, diplontic life cycles, and life cycles with alternation of generations. For instance, in diplontic organisms like most animals, the diploid phase is dominant, and the haploid phase is restricted to the gametes (sperm and eggs).
Conversely, in haploid-dominant organisms, such as most fungi and some algae, the multicellular haploid stage is the dominant life stage. Meanwhile, many plants exhibit an alternation of generations, a cycle with both multicellular haploid and diploid phases that take turns in being the dominant stage of the life cycle. These differences illustrate the complexity of eukaryotic life cycles and show that a haploid phase is not a universal feature for most species.