Describe how plant genes can be manipulated using the ti plasmid

The tumor-inducing plasmids of the bacteria Agrobacterium tumefaciens infects plants and results to unregulated growth of the plant. However, the avirulent form of the bacterium is used to develop the transgenic plant. By introducing desired gene into the transposable region of the bacterium plasmid, the bacterium is infected in plants cells and the gene in traduced and integrated  into the embryonic plant cells. The cells develop into a genetically modified plant.  

step 1: initiation

initiation is the beginning of transcription. it occurs when the enzyme rna polymerase binds to a region of a gene called the promoter. this signals the dna to unwind so the enzyme can ‘‘read’’ the bases in one of the dna strands. the enzyme is now ready to make a strand of mrna with a complementary sequence of bases.

step 2: elongation

elongation is the addition of nucleotides to the mrna strand. rna polymerase reads the unwound dna strand and builds the mrna molecule, using complementary base pairs. there is a brief time during this process when the newly formed rna is bound to the unwound dna. during this process, an adenine (a) in the dna binds to an uracil (u) in the rna.

step 3: termination

termination is the ending of transcription, and occurs when rna polymerase crosses a stop (termination) sequence in the gene. the mrna strand is complete, and it detaches from dna.