Question

What are proto-oncogenes?

Answer 1

our genes are made up of sequences of DNA that contain the information which is necessary for growth and functioning of cells. It is a normal gene found in the cell and is responsible for making protein and each protein has a specialized function in the body. A proto-oncogene can convert into an oncogene if it comes in contact with a carcinogen.

complete answer:-
to answer this question you must know about genes present in our body.
There are millions of cells in our body that grow, divide and die in an orderly fashion. This process is regulated by genes called proto-oncogene within the cell's nucleus. These proto-oncogene genes code for protein, stimulate cell division and prevent apoptosis (cell death). These are the essential processes of maintenance of healthy organs and tissues.
The defective version of proto-oncogene ,known as the oncogene because our normal proto- oncogene in the presence of carcinogens gets converted into oncogenes. These oncogenes can cause cancer in the human body which may be fatal due to abnormal, uncontrolled and functionless growth of cells.
A proto-oncogene can't cause cancer unless a mutation occurs in the gene that turns it into an oncogene. After mutation it strat making too much protein and rapid growth of cells which is out of control and this is the defining feature of cancerous cells. These mutations are called dominant mutations that means only one copy of a gene is mutated in order to encourage cancer.

So, proto-oncogene are normal genes present inside the cells which help the growth and functioning of cells.

Note:
Radiation, smoke and other environmental toxins may play an important role in causing mutation in proto-oncogene as well; some people are more susceptible to mutation in their proto-oncogenes. There are several other mutations that can cause a proto-oncogene to become an oncogene such as point mutation,gene amplification, and chromosomal translocation.