Since, the options are not given the question is incomplete. The complete question is as follows:
Unbeknownst to her or her care team, a 51-year-old woman's breast cancer has an etiology rooted in the fact that tumor suppressor genes are present but have been silenced. Consequently, she has not synthesized normal cancer-suppressing proteins and neoplasia has resulted. What process has accounted for the woman's cancer?
A. Chromosomal translocation
B. The “two-hit” hypothesis of carcinogenesi
s
C. Epigenetic mechanisms
D. A DNA repair defect
Answer: C. Epigenetic mechanisms
Explanation:
In cancer epigenetics the modification of the DNA of the cancer cells occur which will not cause the change in the nucleotide sequence rather it will affect the way, through which the genetic code is being expressed in the body. In cancer different type of epigenetic mechanisms can result which may cause silencing of the tumor suppressor genes, modification of the histone, dysregulation of proteins of DNA, alteration of the methylation pattern of DNA.
According to the given situation, is an example of the epigenetic mechanism of cancer. This is because the tumor suppressor genes of cancer cells are present but these are silenced, that is they are non-functional as a result of this the cancer-suppressing proteins will not be synthesized in the body. This entire condition will be contributing to the neoplasia.
Answer:
A. sharing electrons
Explanation:
A covalent bond consists of the simultaneous attraction of two nuclei for one or more pairs of electrons.
