Which statement best describes the difference between the life cycles of plants and animals? different plants have a different number of phases in their life cycle; humans always have two phases in their life cycle. plants have a one-part life cycle and are entirely diploid; humans spend their lives in a haploid phase. plants have a two-part life cycle, spending part of their life in a diploid phase and part in a haploid phase; humans spend their lives in a diploid phase and produce gametes that are haploid. plants have a one-part life cycle and are entirely haploid; humans have a two-part life cycle, spending part of their life in a diploid phase and part in a haploid phase.