RuBisCO is an enzyme that acts both as a carboxylase and an oxygenase. Why do you think RuBisCO carries out more carboxylation in `C_(4)` plants ?

Why is the colour of a leaf in the dark frequently turns yellow, or pale green ? Which pigment do you think is more stable ?

Assertion : C_(4) photosynthesis is more sensitive to low termperature as compared to C_(3) photosynthesis . Reason : the rubisco found in C_(4) plants is more sensitive to low temperature as compared to C_(3) plants.

By looking at a plant externally can you tell whether a plant is C_(3) or C_(4) ? Why and how ?

Given below are some characteristics of photosynthetic plants. Which of these are true for C_(4) plants (i) Rubisco is present in the mesophyll cells (ii) 3-carbons in the primary CO_(2) acceptor (iii) The primary CO_(2) fixation product is PGA (iv) Possess PEP case. (v) The intitial carboxylation reaction occurs in bundle sheath cells (vi) The calvin cycle takes place in bundle sheath cells (vii) 4-carbon atoms in the primary CO_(2) fixation product.