631190-13-26P AID: 2498 | 25/08/2015
Hox (Homeobox) genes are a series of genes that control the embryological development. They produce protein products that regulate the development pattern of various organs and structures.
Lac operon is a gene regulation mechanism that determines whether the structural genes are transcribed or repressed, depending on the surrounding environment where a cell lives. In lac operon the repressor protein synthesized by gene i binds to operator to inhibit transcription.
If the bacterium is living in the absence of lactose and lactose is suddenly introduced into the bacterium's environment, then immediately when lactose is present in high concentration in the cell, lactose binds to the repressor and makes it unfit for binding. RNA polymerase can then transcribe the structural genes.
Hox protein and Lac repressors both are transcription factors that either allow or repress transcription of various genes, thus regulates the gene expression.