Practice question

Glomeromycota unique because they are obligate symbionts unable to complete life cycle without host plant root, dependent on plant-derived lipids and sugars due to genomic loss. No saprotrophic growth on synthetic media documented despite attempts. They produce large multinucleate asexual spores called glomerospores, lack sexual zygospores, lack septate hyphae, do not form basidiocarps or zoospores. Coenocytic hyphae penetrate root cortex forming arbuscules for exchange. This obligate biotrophy reflects genome loss of fatty acid synthesis genes, requiring host lipid transfer. Conservation highlights evolutionary lineage dating to early Devonian enabling plant colonization of land through mycorrhiza.