© All Rights reserved @ LearnWithDash
Step-by-Step Explanation
Step 1: Understanding the Question
The question describes a plant that:
Avoids photorespiratory losses.
Has improved water-use efficiency.
Shows high rates of photosynthesis at high temperatures.
Has improved efficiency of nitrogen utilization.
We need to determine which physiological group (CAM, Nitrogen fixer, C3, or C4) this plant belongs to.
Step 2: Photorespiration and Why It Matters
Photorespiration is a process that occurs in C3 plants when the enzyme RuBisCO binds to oxygen instead of carbon dioxide, leading to lower efficiency of photosynthesis. Plants that reduce or avoid photorespiration can fix more carbon without wasting resources.
Step 3: Characteristics of C4 Plants
C4 plants have evolved mechanisms to minimize photorespiration. Key features include:
Kranz Anatomy: Bundle sheath cells surround vascular bundles to create an internal environment with a higher concentration of CO2, thereby reducing photorespiration.
High Temperature Tolerance: C4 plants perform efficiently under high light intensity and temperatures, making them suitable for hot and dry climates.
Water-Use Efficiency: Because they need to open their stomata for shorter intervals to fix carbon, C4 plants lose less water, thus improving water-use efficiency.
Improved Nitrogen Utilization: With reduced photorespiration, these plants make more efficient use of available nitrogen.
Step 4: Matching the Plant’s Description to C4 Features
The plant in question matches the traits of C4 species almost perfectly:
They avoid photorespiration.
They use water more efficiently.
They photosynthesize better at high temperatures.
They utilize nitrogen more efficiently.
No other group (CAM, Nitrogen fixers, or C3 plants) fits all these traits as well as C4 plants do.
Step 5: Conclusion
Based on its ability to avoid photorespiration, its higher water-use efficiency, and its effective function at high temperatures, this plant is best classified as a C4 plant.
