Examples of C4 Plants

📚 Quick Study Guide

• ☀️ C4 plants are adapted to high light intensity, high temperatures, and low water availability.
• 🌿 They minimize photorespiration, a wasteful process, by spatially separating initial CO₂ fixation and the Calvin cycle.
• 🧪 The key enzyme involved in initial CO₂ fixation is PEP carboxylase (PEPcase).
• 🌱 C4 plants use a four-carbon molecule (oxaloacetate) as the initial carbon fixation product.
• 🗺️ This process occurs in mesophyll cells, and then the four-carbon molecule is transported to bundle sheath cells where CO₂ is released and enters the Calvin cycle.
• 🧬 Examples include corn, sugarcane, sorghum, and switchgrass.
• 🔢 Efficiency: C4 photosynthesis is more efficient than C3 photosynthesis under specific environmental conditions, particularly high temperatures and low water availability.

Practice Quiz

1. Which of the following is a characteristic adaptation of C4 plants?
   1. Conserving water in hot climates
   2. Performing photosynthesis at night
   3. Thriving in low light conditions
   4. Requiring abundant water supply
2. What enzyme is primarily responsible for initial carbon fixation in C4 plants?
   1. RuBisCO
   2. PEP Carboxylase
   3. Amylase
   4. Nitrogenase
3. In C4 plants, the Calvin cycle occurs in which type of cells?
   1. Mesophyll cells
   2. Epidermal cells
   3. Bundle sheath cells
   4. Guard cells
4. Which molecule is the initial carbon fixation product in C4 plants?
   1. Glucose
   2. Ribulose-1,5-bisphosphate (RuBP)
   3. Oxaloacetate
   4. Glyceraldehyde-3-phosphate (G3P)
5. Which of the following plants is a common example of a C4 plant?
   1. Wheat
   2. Rice
   3. Corn
   4. Soybean
6. What is the primary benefit of the C4 pathway compared to the C3 pathway in hot and dry environments?
   1. Increased oxygen uptake
   2. Reduced photorespiration
   3. Enhanced RuBisCO activity
   4. Greater water usage
7. Where does the initial fixation of CO₂ occur in C4 plants?
   1. Stomata
   2. Bundle sheath cells
   3. Mesophyll cells
   4. Vascular bundles