[Campbell Biology P.926] The text mentions the 'polarity of epithelia,' highlighting their d... | Practice Question

The text mentions the 'polarity of epithelia,' highlighting their distinct apical and basal surfaces. For epithelial cells lining the small intestine, specialized projections called microvilli are found on the apical surface. What is the primary functional significance of these microvilli?

  • A: To increase the surface area available for absorbing nutrients.
  • B: To facilitate cell division and tissue regeneration.
  • C: To provide mechanical strength and protection against abrasion.
  • D: To aid in the transmission of signals between adjacent cells.

Explanation

The text explicitly states regarding the polarity of epithelia: 'For example, the apical surface of the epithelium lining the small intestine is covered with microvilli, projections that increase the surface area available for absorbing nutrients.' This directly supports option A.