Question

At low $C{O}_2$ concentration, photorespiration in $C_3$ and $C_4$ plants respectively is

• A. high, high
• B. low, medium
• C. high, negligible
• D. negligible, high

Answer 1

The correct option is C high, negligible

When availability of carbon dioxide is low, the $C_3$ plants undergo photorespiration. In this process the RuBP combines with oxygen in presence of enzyme RuBisCo instead of carbon dioxide and this turns out to be a wasteful process.
$C_4$ plants avoid photorespiration due to certain adaptations.