Suture separates the large unpaired frontal bone from the two parietal bones

Correct Answer: A

Rationale: The coronal suture runs transversely across the skull, separating the frontal bone (forehead) from the two parietal bones (top sides). This suture, visible as a line in coronal section, allows cranial growth in infancy and fuses later. The sagittal suture, midline, joins the parietal bones, not the frontal. The lambdoid suture separates parietals from the occipital bone posteriorly. 'Frontal' as a suture is incorrect it's the bone itself. The coronal suture's position and function distinguish it, essential for skull structure and development, unlike sagittal or lambdoid orientations or misnamed bone references.

Correct Answer: C

Rationale: Pectoralis major has a convergent fascicle pattern, with fibers fanning from a broad origin (clavicle, sternum) to a narrow insertion (humerus), enhancing force for arm adduction and rotation. Biceps brachii has parallel fascicles along its length for elbow flexion. Gluteus maximus features multipennate fibers for hip extension. Rectus femoris runs parallel for knee extension. Convergent patterns concentrate force from multiple directions, distinguishing pectoralis major's structure and function, key for chest movements, unlike parallel or pennate arrangements.

Correct Answer: C

Rationale: Erector spinae, along the spine, extends and stabilizes it, providing postural support for standing and lifting. Arm movement involves deltoid or biceps. Pelvic stabilization uses gluteals or obliques. Rotation involves rotatores or obliques, not erector spinae's primary extension. Its role in maintaining upright posture distinguishes it, essential for spinal integrity, unlike arm, pelvic, or twisting functions.

Correct Answer: B

Rationale: Vastus intermedius, a quadriceps muscle, lies deep to rectus femoris, which overlays it on the anterior thigh, both extending the knee. Biceps femoris, a hamstring, is posterior. Vastus medialis and lateralis flank it laterally and medially, not superiorly. Rectus femoris' superficial position distinguishes it, key for quadriceps layering.

Correct Answer: D

Rationale: Water's ability to mound above a glass rim results from surface tension, a property arising from cohesive forces between its molecules. Hydrogen bonds create a strong, elastic 'skin' at the surface, resisting external disruption and allowing water to hold together against gravity briefly. Specific gravity relates to density, not this behavior. Cohesion contributes but isn't the complete mechanism. Opacity, transparency-related, is irrelevant. Surface tension's role in forming this temporary barrier, driven by molecular attraction, explains the phenomenon, a key feature in water's physical behavior.