Which metabolic effect overcomes photorespiration during drought conditions when C4 plants close stomata?

💡 Explanation

When C4 plants close stomata during drought, photorespiration increases due to build up of oxygen; spatial separation using PEP carboxylase concentrates CO2 around rubisco by shuttling 4-carbon acids, overcoming oxygen interference because CO2 is fixed in bundle sheath cells restricting rubisco O2 exposure. Therefore spatial separation occurs, rather than temporal separation or increased activity which would reduce photosynthetic yield.

• Which risk increases as a deep-sea siphonophore detaches its gas-filled pneumatophore?
• Which outcome occurs when seasonal changes reduce daylight signals used in avian migration maps?
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