Palisade mesophyll cell; contains a high density of chloroplasts that align near the cell wall to maximize light absorption for photosynthesis.

Root hair cell; possesses an elongated cytoplasmic extension that significantly increases the surface area for the absorption of water and mineral ions.

Guard cell; utilizes unevenly thickened cell walls and turgor pressure changes to control the opening and closing of the stomatal pore.

Phloem sieve tube element; lacks a nucleus and vacuole to offer minimal resistance to the mass flow of sucrose and amino acids.