Which mechanism is least likely to inactivate a tumor-suppressor gene?Group of answer choicesmutationchemical modificationloss of heterozygositygene duplication

The mechanism least likely to inactivate a tumor-suppressor gene is gene duplication.

Here's why:

1. Mutation: A mutation can directly inactivate a tumor-suppressor gene by altering its DNA sequence, which can lead to a non-functional protein product.

2. Chemical Modification: Chemical modifications, such as methylation, can inactivate a tumor-suppressor gene by preventing it from being transcribed and translated into a functional protein.

3. Loss of Heterozygosity: Loss of heterozygosity can inactivate a tumor-suppressor gene if the remaining copy of the gene also becomes inactivated. This is because tumor-suppressor genes are typically recessive, meaning both copies of the gene need to be inactivated for a tumor to form.

4. Gene Duplication: This is the least likely mechanism to inactivate a tumor-suppressor gene. Gene duplication results in an extra copy of a gene. While this can lead to overexpression if the gene is a proto-oncogene (a normal gene that can become an oncogene due to mutations or increased expression), it is less likely to inactivate a tumor-suppressor gene because the extra copy would also need to be inactivated for a tumor to form.

The mechanism least likely to inactivate a tumor-suppressor gene is gene duplication.

Here's why:

1. Mutation: A mutation can directly inactivate a tumor-suppressor gene by altering its DNA sequence, which can lead to a non-functional protein product.

2. Chemical Modification: Chemical modifications, such as methylation, can inactivate a tumor-suppressor gene by preventing it from being transcribed and translated into a functional protein.

3. Loss of Heterozygosity: This refers to the loss of the normal, functioning copy of a gene in a cell that already has one mutated copy of that gene. This can lead to the complete loss of function of a tumor-suppressor gene.

4. Gene Duplication: This process results in an extra copy of a gene. While this can lead to an overproduction of the protein product, it is less likely to inactivate the gene. The original gene is still present and capable of producing a functional protein, unless it also undergoes a harmful mutation.