Fungus commonly known as sac fungi or ascomycetes, constitute the largest taxonomic group within the Eumycota. These fungi form meiotic spores called ascospores, which are enclosed in a special sac-like structure called an ascus. This phylum includes morels, a few mushrooms and truffles, unicellular yeasts (e.g., of the genera "Saccharomyces", "Kluyveromyces", "Pichia", and "Candida"), and many filamentous fungi living as saprotrophs, parasites, and mutualistic symbionts (e.g. lichens). Prominent and important genera of filamentous ascomycetes include "Aspergillus", "Penicillium", "Fusarium", and "Claviceps". Many ascomycete species have only been observed undergoing asexual reproduction (called anamorphic species), but analysis of molecular data has often been
Chlorophyll tetrapyrroles known as nonfluorescent chlorophyll catabolites (NCC's) with the general structure: These compounds have also been identified in several ripening fruits. Measurement of the absorption of light is complicated by the solvent used to extract the chlorophyll from plant material, which affects the values obtained, By measuring the absorption of light in the red and far red regions, it is possible to estimate the concentration of chlorophyll within a leaf. Ratio fluorescence emission can be used to measure chlorophyll content. By exciting chlorophyll "a" fluorescence at a lower wavelength, the ratio of chlorophyll fluorescence emission at and can provide a