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
History of biology study of animals and plants. "Natural history" referred to the descriptive aspects of biology, though it also included mineralogy and other non-biological fields; from the Middle Ages through the Renaissance, the unifying framework of natural history was the "scala naturae" or Great Chain of Being. "Natural philosophy" and "natural theology" encompassed the conceptual and metaphysical basis of plant and animal life, dealing with problems of why organisms exist and behave the way they do, though these subjects also included what is now geology, physics, chemistry, and astronomy. Physiology and (botanical) pharmacology were the province of medicine. "Botany", "zoology", and (in