Question

The theory which suggests that the CO${}_2$ produced in respiration plays an important role in mineral absorption is

• A. Contact exchange theory
• B. Carbonic acid exchange theory
• C. Active absorption theory
• D. None of the above

Answer 1

The correct option is B Carbonic acid exchange theory

According to carbonic acid exchange theory, roots liberate significant quantities of carbon dioxide during respiration, which when dissolved in soil water produces carbonic acid, which is ionized into protons and bicarbonate ions. The protons thus formed are capable of exchanging with any bound cations on clay particles and make the bound cations available for the roots.

So, the correct answer is option B.