What causes the lac operon to be turned off?

When lactose is not present, the DNA-binding protein called ► lac repressor binds to a region called the operator, which switches the lac operon off. When lactose binds to the repressor, it causes the repressor to fall off the operator, turning ► the operon on.

How does lac operon switched on and switched off Class 12?

The operon is turned on and off in response to the glucose and lactose levels: catabolite activator protein and lac repressor. The lac repressor blocks the transcription of the operon. In the presence of lactose, it stops acting as a repressor.

Which of the following is an epigenetic mechanism for turning genes off?

DNA Methylation Typically, this group is added to specific places on the DNA, where it blocks the proteins that attach to DNA to “read” the gene. This chemical group can be removed through a process called demethylation. Typically, methylation turns genes “off” and demethylation turns genes “on.”

Why do you think the terms on and off are written under the genes?

Gene regulation is an important part of normal development. Genes are turned on and off in different patterns during development to make a brain cell look and act different from a liver cell or a muscle cell, for example. Gene regulation also allows cells to react quickly to changes in their environments.

What do cells contain that turn genes on or off?

gene regulatory proteins
The gene regulatory proteins allow the individual genes of an organism to be turned on or off specifically. Different selections of gene regulatory proteins are present in different cell types and thereby direct the patterns of gene expression that give each cell type its unique characteristics.

What is the function of lac operon Class 12?

Lac operon explains regulation of enzyme synthesis by the substrate.

What does the lac operon consist of how is the operator switch turned on and off in the expression of genes in this operon explain?

The lac operon consists of series of three genes in bacteria that produce the necessary enzymes to metabolise lactose and it also contains promotar and terminator regions. The three genes are lacZ, lacY and lacA. This protein will bind to the operator region of the lac operon until molecules of lactose bind to it.