Question

The genes responsible for hairy root formation are located on

• A. Ti plasmid
• B. Ri plasmid
• C. F plasmid
• D. R plasmid

Hint:

Remember: \[ \boxed{ \begin{aligned} \text{Ti plasmid} &\rightarrow \text{Crown gall} \text{Ri plasmid} &\rightarrow \text{Hairy root} \end{aligned} } \]

Answer 1

The Correct Option is B

Step 1: Recall the plasmids of Agrobacterium. \[ \begin{aligned} \textit{Agrobacterium tumefaciens} &\rightarrow \text{Ti plasmid (crown gall disease)} \textit{Agrobacterium rhizogenes} &\rightarrow \text{Ri plasmid (hairy root disease)} \end{aligned} \]

Step 2: Identify the correct plasmid. Hairy root formation is caused by genes present on the \[ \boxed{\text{Ri plasmid}.} \] Therefore, \[ \boxed{(B)} \] is the correct answer.