Question

Brainstorm how you think mutations occur in proto-oncogenes and tumor suppressor genes that can lead to cancer.

Answer 1

Mutations in tumor-suppressor genes and proto-oncogenes can lead to cancer by allowing cells with damaged DNA to divide. Proto-oncogenes normally help control cell division, but mutations in these genes turn them into oncogenes that promote the division of cells with damaged DNA.

Step-by-step explanation:

Mutations that lead to cancer usually occur in genes that control the cell cycle. These include tumor-suppressor genes and proto-oncogenes. Tumor-suppressor genes normally prevent cells with damaged DNA from dividing. Mutations in these genes prevent them from functioning normally. As a result, cells with damaged DNA are allowed to divide. Proto-oncogenes normally help control cell division. Mutations in these genes turn them into oncogenes, which promote the division of cells with damaged DNA.

Answer 2

Mutations in proto Oncogenes make it an oncogene and mutation in Tumour suppressor gene makes proteins which cannot stop a cell division. Both of these reasons lead to cancer.

Step-by-step explanation:

A proto oncogene is present in each an every cell of a human. Now the proto Oncogenes code for the proteins that help in cellular growth. A mutation in this gene lead to uncontrolled secretion of proteins that initiate uncontrolled cellular growth. This causes cancer.

A Tumour suppressor gene codes for proteins that help in checking the cell division when there is a contact with nearby cell. This phenomenon is called contact inhibition. Now as this gene is mutated, the protein that is produced is defective and is unable to control the cell division when there is contact with nearby cell. Thus, this uncontrolled cell growth leads to cancer.