6.4 - Gas exchange in leaves

• What's a dicotyledonous plant ?

  A flowering plant with seeds that typically have two embryonic leaves or cotyledons
• What 2 processes maintain diffusion gradients in leaves and where do they occur ?

  Respiration in mitochondria and photosynthesis in chloroplasts
• Describe the structure of a leaf from top to bottom ?

  Waxy cuticle, upper epidermis, palisade mesophyll, spongy mesophyll with a vascular bundle, lower epidermis, guard cells and stomata
• 5 ways leaves are adapted for gas exchange ?

  Thin for short diffusion distance, spongy mesophyll provides large SA for diffusion, extensive airspace between mesophyll cells so gases can easily come in contact with cells, many stomata so diffusion pathway is small