  We propose a principle of consistency between different hierarchical levels
of biological systems. Given a consistency between molecule replication and
cell reproduction, universal statistical laws on cellular chemical abundances
are derived and confirmed experimentally. They include a power law distribution
of gene expressions, a lognormal distribution of cellular chemical abundances
over cells, and embedding of the power law into the network connectivity
distribution. Second, given a consistency between genotype and phenotype, a
general relationship between phenotype fluctuations by genetic variation and
isogenic phenotypic fluctuation by developmental noise is derived. Third, we
discuss the chaos mechanism for stem cell differentiation with autonomous
regulation, resulting from a consistency between cell reproduction and growth
of the cell ensemble.
