• (A) C and D only
• (B) A and C only
• (C) B and D only
• (D) D and E only

Step-by-Step Explanation

To identify the correct statements, let's analyze each one based on oncological principles:

• Statement A (Correct): Computed Tomography (CT) uses X-rays to generate 3D images, and Magnetic Resonance Imaging (MRI) uses strong magnetic fields and non-ionizing radiation to detect pathological changes in internal organs accurately.
• Statement B (Incorrect): Chemotherapeutic drugs are designed to target and kill rapidly dividing cancerous cells, not non-cancerous (normal) cells, although they may have side effects on healthy tissues.
• Statement C (Correct): α-interferon is a type of biological response modifier that is administered to cancer patients to activate their immune system, which then helps in identifying and destroying tumor cells.
• Statement D (Incorrect): While immunotherapy uses biological response modifiers, chemotherapeutic drugs themselves are chemical agents, not biological response modifiers.
• Statement E (Incorrect): In leukaemia (blood cancer), there is an uncontrolled, abnormal increase in the white blood cell count, not a decrease.

Therefore, only statements A and C are correct, leading to option (B).

Related Theory

Cancer is one of the most dreaded diseases globally, characterized by the breakdown of normal regulatory mechanisms of cell growth and differentiation. Understanding its detection and therapeutic approaches is essential for NEET aspirants.

1. Techniques for Cancer Detection

Early detection is crucial for successful treatment. Common techniques include:

• Biopsy and Histopathological studies: A piece of suspected tissue is cut into thin sections, stained, and examined under a microscope.
• Computed Tomography (CT): Utilizes X-rays to produce a three-dimensional image of the internals of an object.
• Magnetic Resonance Imaging (MRI): Employs very strong magnetic fields and non-ionizing radiations to accurately detect pathological and physiological changes in living tissues. It is considered safer than CT as it avoids ionizing radiation.

2. Cancer Treatment Modalities

The common approaches for treatment are surgery, radiation therapy, and immunotherapy.

• Radiotherapy: Tumor cells are irradiated lethally, taking proper care of the normal tissues surrounding the tumor mass.
• Chemotherapy: Several chemotherapeutic drugs are used to kill cancer cells. Some of these are specific for particular tumors. Most drugs have side effects like hair loss, anemia, etc.
• Immunotherapy: Tumor cells often avoid detection and destruction by the immune system. Therefore, patients are given substances called biological response modifiers such as α-interferon, which activates their immune system and helps in destroying the tumor.

3. Leukaemia: The Blood Cancer

Leukaemia is a group of blood cancers that usually begin in the bone marrow and result in high numbers of abnormal blood cells. These cells are not fully developed and are called blasts or leukemia cells. Contrary to common misconceptions, the hallmark of leukaemia is an extravagant increase in the leukocyte count (WBCs), which crowds out healthy blood cells.

4. Properties of Cancer Cells

Normal cells show a property called contact inhibition by virtue of which contact with other cells inhibits their uncontrolled growth. Cancer cells appear to have lost this property. As a result, cancerous cells continue to divide giving rise to masses of cells called tumors.

Frequently Asked Questions (FAQs)