Plants

• What are the three key layers for gas exchange in a dicotyledonous leaf?

  • Spongy mesophyll
  • Palisade mesophyll
  • Stomata
• What is the singular form of stomata?

  Stoma
• What forms the gap known as a stoma?

  Two guard cells
• Where is the primary site of gas exchange in the leaf?

  At the stomata
• What gas diffuses into the leaf for photosynthesis?

  Carbon dioxide
• Where does carbon dioxide diffuse after entering the leaf?

  Into the spongy mesophyll
• Why does carbon dioxide diffuse into the spongy mesophyll?

  To maintain a concentration gradient
• What is the primary function of the palisade mesophyll?

  Photosynthesis
• What does the vascular bundle contain?

  Xylem and phloem
• What is the role of xylem in the vascular bundle?

  Transport water and minerals
• What does phloem transport?

  Sucrose
• What shape are the cells in the palisade mesophyll?

  Narrow and oblong
• Why are palisade mesophyll cells packed closely together?

  To maximize light absorption
• What is the primary product of photosynthesis?

  Oxygen
• Why do stomata mainly close at night?

  To reduce water loss
• What are xerophytic plants adapted to survive?

  Harsh conditions with little water
• What adaptations do xerophytic plants have to limit water loss?

  • Curled leaves to trap moisture
  • Hair-like structures to retain humidity
  • Sunken stomata to reduce evaporation
  • Thicker cuticle to prevent water loss
  • Longer roots to access water
• What is the advantage of curled leaves in xerophytic plants?

  Traps moisture and reduces evaporation
• What do the hair-like structures on xerophytic plants do?

  Trap evaporated water
• How do sunken stomata help xerophytic plants?

  Reduce evaporation by trapping moisture
• What is the purpose of a thicker cuticle in xerophytic plants?

  To prevent evaporation
• Why do xerophytic plants have longer roots?

  To reach water at greater distances
• What is the relationship between stomata and photosynthesis?

  • Stomata allow carbon dioxide in for photosynthesis
  • Oxygen produced during photosynthesis diffuses out
  • Stomata open during the day and close at night