Q110.Which blood component is often abnormally reduced because of bone-marrow failure in leukaemia?
(a) Synovial fluid
(b) Bile
(c) Tooth dentine
(d) Platelets
Answer: (d) Platelets
Explanation: Abnormal cells in leukaemia can crowd out normal marrow production. Reduced platelets cause easy bruising or bleeding; reduced red cells cause anaemia, while impaired normal white cells increase infection risk. The effects depend on the tissue involved and extent of spread.
Q109.Which examination technique uses tissue under a microscope to confirm many cancers?
(a) Height measurement
(b) Pulse counting alone
(c) Biopsy and histopathology
(d) Urine colour alone
Answer: (c) Biopsy and histopathology
Explanation: A biopsy removes cells or tissue for microscopic examination. Histopathology can identify malignant cells, tumour type and important characteristics. Imaging may suggest a tumour, but tissue diagnosis is often required. Tumour type and stage guide decisions about diagnosis and treatment options.
Q108.What is the term for cancer arising from epithelial tissue?
(a) Lymphoma
(b) Carcinoma
(c) Myeloma
(d) Sarcoma
Answer: (b) Carcinoma
Explanation: Carcinomas originate from epithelial cells lining the skin, glands and many organs. Sarcomas arise in connective tissues, while lymphomas and myelomas originate from different immune or blood-cell lineages. Early evaluation is important because clinical behaviour differs greatly between tumour types.
Q107.A sarcoma most commonly arises from which tissue category?
(a) Connective or supporting tissues
(b) Tooth enamel only
(c) Brain fluid
(d) Skin epithelium only
Answer: (a) Connective or supporting tissues
Explanation: Sarcomas are malignant tumours of connective or mesenchymal tissues such as bone, cartilage, fat and muscle. They differ from carcinomas, which begin in epithelial tissues such as the lung or intestine. The effects depend on the tissue involved and extent of spread.
Q106.Which cobalt isotope is widely known for use as a gamma-ray source in radiotherapy?
(a) Carbon-14
(b) Iodine-127
(c) Cobalt-59
(d) Cobalt-60
Answer: (d) Cobalt-60
Explanation: Cobalt-60 emits gamma radiation and has been used in external-beam radiotherapy. Modern treatment may also use linear accelerators. Radiation doses must be planned to destroy cancer cells while sparing healthy structures. Tumour type and stage guide decisions about diagnosis and treatment options.
Q105.Which inherited change can increase breast and ovarian cancer susceptibility?
(a) ABO blood group O
(b) Lactase persistence
(c) Pathogenic BRCA1 or BRCA2 variant
(d) Normal haemoglobin A
Answer: (c) Pathogenic BRCA1 or BRCA2 variant
Explanation: Certain pathogenic BRCA1 and BRCA2 variants impair DNA-repair pathways and increase susceptibility to several cancers. Carrying a variant raises risk but does not mean that cancer is inevitable. Early evaluation is important because clinical behaviour differs greatly between tumour types.
Q104.Insulin is secreted mainly by which pancreatic cells?
(a) Alpha cells
(b) Beta cells
(c) Acinar cells
(d) Delta cells
Answer: (b) Beta cells
Explanation: Pancreatic beta cells in the islets of Langerhans release insulin in response to rising blood glucose. Insulin facilitates glucose storage and uptake, helping maintain blood glucose within a healthy range. Early recognition helps prevent avoidable metabolic and vascular complications over time.
Q103.Which hormone generally raises blood glucose by stimulating glycogen breakdown?
(a) Glucagon
(b) Oxytocin
(c) Melatonin
(d) Insulin
Answer: (a) Glucagon
Explanation: Glucagon is secreted by pancreatic alpha cells. It helps maintain blood glucose between meals, especially by promoting liver glycogen breakdown and glucose production. Insulin generally has the opposite blood-glucose-lowering effect. Long-term care also considers risks to eyes, nerves, kidneys and blood vessels.
Q102.What is the main underlying mechanism of type 1 diabetes mellitus?
(a) Abnormal collagen in skin
(b) Excess iodine consumption
(c) Lack of ADH alone
(d) Autoimmune destruction of pancreatic beta cells
Answer: (d) Autoimmune destruction of pancreatic beta cells
Explanation: In type 1 diabetes, immune-mediated destruction of pancreatic beta cells produces marked insulin deficiency. Individuals usually require insulin replacement. Type 2 diabetes more commonly involves insulin resistance alongside declining beta-cell function. The exact mechanism determines which treatments and monitoring strategies are useful.
Q101.Type 2 diabetes mellitus is most strongly associated with which metabolic abnormality?
(a) High ADH secretion
(b) Excess vitamin C
(c) Insulin resistance
(d) Absence of all digestive enzymes
Answer: (c) Insulin resistance
Explanation: Type 2 diabetes usually begins with reduced responsiveness to insulin in tissues, and pancreatic insulin secretion may later become insufficient. Genetics, adiposity, age and inactivity contribute to risk. Early recognition helps prevent avoidable metabolic and vascular complications over time.
