[A structure in the head of a spermatozoon that contains acid hydrolases, and is concerned with the breakdown of the outer membrane of the ovum during fertilization. It lies just beneath the plasma membrane and is derived from the lysosome.]
[Obsolete. Use PO:0020093 from Plant Ontology instead. OBSOLETE, use term from plant ontology. A cell located at the chalazal end of the mature embryo sac in angiosperms.]
[Hematopoietic cells resident in the bone marrow. Include: hematopoietic stem cells (lymphoid stem cells and myeloid stem cells) and the precursor cells for thrombocytes, erythrocytes, basophils, neutrophils, eosinophils, monocytes and lymphocytes.]