Question

Match the following \[ \begin{array}{|c|l|c|l|} \hline & List-I & & List-II \hline A & \textit{Azotobacter} & I & \text{Anaerobic nitrogen fixer} B & \textit{Clostridium} & II & \text{Symbiotic nitrogen fixer} C & \textit{Rhizobium} & III & \text{Free-living aerobic fixer} D & \text{Leghemoglobin} & IV & \text{Oxygen buffering protein} \hline \end{array} \] The correct answer is

• A. A -- III, B -- I, C -- II, D -- IV
• B. A -- I, B -- III, C -- IV, D -- II
• C. A -- I, B -- IV, C -- II, D -- III
• D. A -- IV, B -- II, C -- III, D -- I

Hint:

Important associations: \[ \boxed{ \begin{aligned} \textit{Azotobacter} &\rightarrow \text{Aerobic nitrogen fixer} \textit{Clostridium} &\rightarrow \text{Anaerobic nitrogen fixer} \textit{Rhizobium} &\rightarrow \text{Symbiotic nitrogen fixer} \text{Leghemoglobin} &\rightarrow \text{Maintains low oxygen concentration in root nodules} \end{aligned} } \]

Answer 1

The Correct Option is A

Step 1: Match each organism with its characteristic. \[ \boxed{ \begin{aligned} \textit{Azotobacter} &\rightarrow \text{Free-living aerobic nitrogen fixer (III)} \textit{Clostridium} &\rightarrow \text{Anaerobic nitrogen fixer (I)} \textit{Rhizobium} &\rightarrow \text{Symbiotic nitrogen fixer (II)} \text{Leghemoglobin} &\rightarrow \text{Oxygen buffering protein (IV)} \end{aligned} } \]

Step 2: Write the correct matching. Thus, \[ \boxed{ A-\mathrm{III},\; B-\mathrm{I},\; C-\mathrm{II},\; D-\mathrm{IV} } \] Therefore, \[ \boxed{(A)} \] is the correct answer.