The histogram of MeSH term frequency of Operon

MeSH term

Count
Lac Operon	115
Operon	26
*Lac Operon	8
*Operon	11
Lac Operon/genetics	28
Operon/genetics	2
Lac Operon/physiology	7
Lac Operon/*physiology	2
Lac Operon/*genetics	3
Lac Operon/drug effects	2
Lac Operon/*drug effects	2
rRNA Operon/physiology	1
Lac Operon/drug effects/*physiology	1