The finger-like projections in the small intestine that increase the surface area for absorption are: MCQ with Answer and Explanation

Explanation:
The sternum, or breastbone, is a flat bone located in the center of the chest, to which the ribs attach. The clavicle, commonly known as the collarbone, connects the arm to the body, running horizontally above the first rib. The scapula, or shoulder blade, is a flat, triangular bone located on the upper back, forming the posterior part of the shoulder girdle. All statements are correct.

Explanation:
Stem bears leaves and reproductive structures. It is positively phototropic (grows towards light). Leaves are the main photosynthetic organs. Roots grow downward.

Explanation:
Enterokinase (enteropeptidase) is secreted by the intestinal mucosa and activates the pancreatic proenzyme trypsinogen to trypsin, which then activates other zymogens. Pepsin is active in the stomach, renin is a milk-curdling enzyme (chymosin), carboxypeptidase is a pancreatic protease. This cascade ensures that protein-digesting enzymes are activated only in the appropriate location to prevent autodigestion.