UPSC Prelims 2014 Question:

Consider the following techniques/phenomena:

1. Budding and grafting in fruit plants 
2. Cytoplasmic male sterility 
3. Gene silencing
   
   

Which of the above is/are used to create transgenic crops?

Explanation: 

• • A transgenic crop is a genetically modified organism (GMO). Transgenic indicates that a transfer of genes has occurred using recombinant DNA technology. Generally, a transgenic crop contains one or more genes that have been inserted artificially either from an unrelated plant or from different species altogether.
    
    
  • In order to make a transgenic crop, there are five main steps: extracting DNA, cloning a gene of interest, designing the gene for plant infiltration, transformation, and finally plant breeding
    
    
  • Some techniques which are used to create transgenic crops are: 

• Gene silencing: It is an interruption or suppression of the expression of a gene at transcriptional or translational levels.
  
  

• Cytoplasmic male sterility: It is a condition under which a plant is unable to produce functional pollen, is widespread among higher plants. CMS systems represent a valuable tool in the production of hybrid seed in self-pollinating crop species, including maize, rice, cotton, and a number of vegetable crops.
  
  

• • Agrobacterium method: Agrobacterium-mediated genetic transformation is the most widely used biotechnological method in plant gene function analysis and crop improvement.
    
    

Therefore, option (2) is the correct answer. 

Subject: Environment | Plant and Animal Anatomy