Carcinogens and Cellular Oncogenes — NEET Biology
📚 Practice ConceptCauses of cancer: Transformation of normal cells into cancerous neoplastic cells may be induced by physical, chemical or biological agents. These agents are called carcinogens. Ionising radiations like X-rays and gamma rays and non-ionizing radiations like UV cause DNA damage leading to neoplastic transformation. The chemical carcinogens present in tobacco smoke have been identified as a major cause of lung cancer. Cancer causing viruses called oncogenic viruses have genes called viral oncogenes. Furthermore, several genes called cellular oncogenes (c-onc) or proto oncogenes have been identified in normal cells which, when activated under certain conditions, could lead to oncogenic transformation of the cells.
Q7. Match the Column Column I (Gene Type) A. Proto-oncogene B. Viral oncogene C. Tumour suppressor gene Column II (Effect) i. Introduced by oncogenic viruses ii. Causes cancer when abnormally activated iii. Normally inhibits cell proliferation
View solution & NCERT explanation
Correct answer: B — A–ii, B–i, C–iii
Each gene class is linked with its function or abnormal effect on cell cycle.
What does NCERT say about Causes cancer Transformation normal?
Has this concept appeared in NEET?
Which chapter is this from?
Through deep analysis of NEET and NTA, 176 of the 180 ReNEET 2026 (June 21) questions were already in the MedicNEET question bank before the exam.
176/180MedicNEET's Biology question bank is built from the same NCERT lines NTA picks repeatedly. Not random MCQs — questions crafted exactly like NTA crafts them.