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
Philosophy of biology macromolecules to the study of co-operation in social systems. By clarifying and restricting the use of the term to describe and explain systems controlled strictly scientifically by genetic programmes, or other physical systems, teleological questions can be framed and investigated while remaining committed to the physical nature of all underlying organic processes. Similar attention has been given to the concepts of "natural selection" (what is the target of natural selection? - the individual? the environment? the genome? the species?); "adaptation; diversity and classification; species and speciation"; and "macroevolution". Just as biology has developed as an autonomous discipline in full conversation