Which of the following diseases can be prevented by the BCG vaccine? MCQ with Answer and Explanation

Explanation:
Myosin is the motor protein forming thick filaments; its heads bind to actin thin filaments and generate force via the cross-bridge cycle. Actin forms thin filaments, troponin and tropomyosin regulate contraction. The sliding filament theory describes muscle shortening without filament length change.

Explanation:
The Blood-Brain Barrier (BBB) is formed by tight junctions between endothelial cells in brain capillaries, making it highly selective. It allows the free diffusion of small, lipid-soluble molecules and essential gases. Therefore, oxygen, carbon dioxide, and lipid-soluble substances (like alcohol, nicotine, and some anesthetics) easily cross. Glucose, a water-soluble molecule essential for brain energy, crosses via specific carrier-mediated transport (GLUT1 transporters). Large proteins, peptides, most water-soluble drugs, and pathogens like bacteria and viruses are generally blocked from entering the brain parenchyma.

Explanation:
Oxytocin stimulates uterine smooth muscle contractions during childbirth and milk ejection during lactation. Thyroxine regulates metabolism; calcitonin and parathyroid hormone control blood calcium. Insulin lowers blood glucose. Adrenaline increases heart rate, not decreases. This question tests the core functions of major hormones.