Q1. The prothalli are bisexual, free-living and photosynthetic. At maturity, the prothallus is flat and heart-shaped. Inspect the lower surface for rhizoids, antheridia and archegonia. What is the function of each of these structures?

Q2. First, is it in fact true that cyanobacteria have evolved little, if at all, because Proterozoic time? And second, if that is true, how can it be explained why did these primitive prokaryotes not evolve, whereas eukaryotes obviously did?