Cancer Development and Oncogenic Transformation — NEET Biology
📚 Practice ConceptThe mechanisms that underlie development of cancer or oncogenic transformation of cells, its treatment and control have been some of the most intense areas of research in biology and medicine.
Which of the above statements are correct? S1: Malignant tumor cells are characterized by a loss of contact inhibition and their ability to metastasize through blood. S2: Radiotherapy involves irradiating tumor cells lethally, while chemotherapy primarily uses biological response modifiers to activate the immune system. S3: Computed tomography (CT) utilizes strong magnetic fields and non-ionising radiations for precise detection of physiological changes in living tissues. S4: Proto-oncogenes are normally present in cells and their activation under specific conditions can lead to oncogenic transformation. S5: Early detection of cancers, often based on histopathological studies of tissues, is crucial for successful treatment outcomes.
View solution & NCERT explanation
Correct answer: B — Only S1, S4 and S5 are correct.
The question assesses understanding of cancer characteristics, detection, and treatment methods. S1: Malignant tumor cells lose contact inhibition, leading to uncontrolled growth, and they can metastasize by spreading through blood to distant sites. This statement is correct, as malignant tumors are defined by these properties. S2: Radiotherapy indeed involves lethal irradiation of tumor cells. However, chemotherapy primarily uses various drugs to kill cancerous cells, while biological response modifiers like alpha-interferon are used to activate the immune system. Therefore, this statement is incorrect as it misrepresents the primary mechanism of chemotherapy. S3: Computed tomography (CT) uses X-rays to generate three-dimensional images of internal organs. Magnetic Resonance Imaging (MRI) uses strong magnetic fields and non-ionising radiations for accurate detection of pathological and physiological changes. Thus, the statement incorrectly describes the principle of CT using MRI's features, making it incorrect. S4: Proto-oncogenes, also known as cellular oncogenes (c-onc), are genes identified in normal cells. When these genes are activated under certain conditions, they can indeed lead to the oncogenic transformation of cells. This statement is correct. S5: Early detection of cancers is critical for successful treatment. Diagnostic methods like biopsy and histopathological studies of suspected tissues are fundamental to cancer detection. This statement is correct. Based on the analysis, statements S1, S4, and S5 are correct.
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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.