15. 3T3 cell lines are not normal cell line but are continuous cell line for solid tumor. They were prepared after 3 days of transfer. So yes we can say they were immortalized immediately. It has been reported that NIH 3T3 cell lines were evolved within the firat 25 days of transfer from diploid to a tetraploid cell line.
So, option C is the only incorrect because they are not normal karyotype but are immortalized cancer cell lines.
16. The phenotypes of identical twins drifts apart over years becauss of the environmental factors which regulates the expression pattern without changing the gene. So, option B is correct.
17. Aflatoxin B is leading cause of cancer in the US.
18. Triple negative breast is defined by the absence of estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor-2 (HER2) expression. Her2 is also known as erbB2. So, option D is correct.
Aberant signalling thriugh ras has been studied in TNBC.
Overexpression of MDM2 strongly promotes cell proliferation and tumor cell circulation in TNBC. It help in potential metastasis.
TNBC has shown over expression of cyclin D1.
cancer biology 15. The carly pioneers of oncogene research were using a 3T3 cell transformation assay,...