Some Single-Celled Eukaryotas on Earth reproduce both sexually and asexually (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC16239/). Could something like this be added:
For example (sexual reproduction) grants microbes more genetic variety, which in-game could be more Mutation Points.
How could be it done? Second nucleus. Two cells come close to each other and combine membranes. They exchange “sexual” nucleus which results in reproduction.