Crozier (mycology) Crozier (mycology) A crozier is an anatomical feature of many fungi in the phylum Ascomycota that form at the base of asci and look like hook-topped shepherd’s staffs or stylized religious crosiers. During the ascus initial formation the crozier helps to maintain a dikaryotic state in the ascus initial and its side branch that will continue the spreading growth of the ascogenous hyphae in Ascomycota fruitbodies. The tips of developing asci on these ascogenous hyphae curl over. One haploid nucleus migrates into the curved tip while the other compatible haploid nucleus remains in the penultimate space below the hook. The
Microbial population biology of the microscopic rather than the macroscopic organism. A good deal of microbial population biology may be described also as microbial evolutionary ecology. On the other hand, typically microbial population biologists (unlike microbial ecologists) are less concerned with questions of the role of microorganisms in ecosystem ecology, which is the study of nutrient cycling and energy movement between biotic as well as abiotic components of ecosystems. Microbial population biology can include aspects of molecular evolution or phylogenetics. Strictly, however, these emphases should be employed toward understanding issues of microbial evolution and ecology rather than as a means of understanding more