The question asks in which pairs the structures play comparable roles in the plant and animal life cycles. In plant life cycles, significant structures include:
- Sporophyte: the diploid multicellular stage producing spores.
- Gametophyte: the haploid multicellular stage producing gametes.
- Spores: haploid cells that grow into gametophytes.
- Gametes: haploid reproductive cells that fuse to form a zygote.
In animal life cycles, the main comparable structures include:
- The adult organism (diploid) producing haploid gametes by meiosis.
- Gametes (haploid reproductive cells).
- Zygote (diploid fertilized egg).
Key comparisons:
- The plant sporophyte corresponds to the adult animal organism as both are diploid multicellular stages.
- Plant gametes and animal gametes have comparable roles as haploid reproductive cells.
- Plant spores have no direct animal equivalent because animals do not have a multicellular spore phase.
Thus, pairs where structures play comparable roles in plant and animal life cycles include:
- Plant sporophyte and adult animal organism (both diploid multicellular generations).
- Plant gametes and animal gametes (both haploid reproductive cells).
I found this pattern clearly outlined in the alternation of generations typical in plants versus the direct production of gametes by animals from a diploid adult stage.
If specific pairs are given in choices, the answer would be those pairs including these analogous structures.
