Question

In some succulent plants like Opuntia the R. Q. is zero because

• A. $O_2$ is absorbed but $C{O}_2$ is not released.
• B. $C{O}_2$ is released without any absorption of $O_2$
• C. There is often compensation point in these plants due to thick phylloclades.
• D. None of the above

Answer 1

The correct option is A $O_2$ is absorbed but $C{O}_2$ is not released.

In succulent plants like Opuntia there is an incomplete oxidation of the carbohydrates resulting in the
formation of organic acids. CO2 is not released.
$2C_6{H}_{1}2O_6+3O_2\to 3C_4{H}_6{O}_5+3H_{2}O+386kcal.$
$RQ=C{O}_2/O_2=0/3=0$