Answer: Active, energy-dependent transport across the intestinal epithelium.
- A Passive diffusion driven purely by their concentration gradient
- B Bulk endocytosis of luminal fluid by enterocytes
- C Active, energy-dependent transport across the intestinal epithelium
- D Direct transport through intercellular gaps between enterocytes
Correct answer: C. Active, energy-dependent transport across the intestinal epithelium
Explanation: Glucose and amino acids are largely absorbed by active transport (often coupled to sodium ion gradients) across the intestinal mucosa, allowing absorption even against a concentration gradient.
The human digestive system. Image: LadyofHats (Mariana Ruiz), Public Domain, via Wikimedia Commons.
Concept context
The digestive tract, digestive enzymes, hormonal control of digestion, and liver function. High NEET weightage.