a self-development unit with the mosaic-type development

a specialized embryo at a certain stage of development in an organism

a specialized embryo being both at a certain stage of development and a component of the whole plant

a relatively independent part in an organism, and it has relatively definite boundary to the regions around it both in structure and function ,and also has a relative integrity both in structure and function inside itself

a universal structural and functional unit of an organism

a relatively independent new individual first, and then it may be the component of the plant