Answer choices: Scientists routinely use Agobacterium to generate transgenic pla
ID: 196222 • Letter: A
Question
Answer choices:
Scientists routinely use Agobacterium to generate transgenic plants. Agrobacterium is a plant pathogen that facilitates the insertion of a foreign DNA (T-DNA) into the plant genome. The graph below illustrates the structure of PIN3 wild type allele and the pin3 mutant allele containing a T-DNA insertion. Black boxes: coding sequences; white boxes: UTRs; lines between the boxes: introns; arrows: location of the PCR primers (the direction of the arrow is from 5' to 3"of the primer). Before studying the function of PIN3, you need to perform genotyping PCR to distinguish wild type plants from pin3 mutant plants. The distance between primer 2 and 3 is 500 bp. The distance between primer 1 and 3 is 5400 bp. The T-DNA insertion is 5000 bp. The PCR parameter is 30 cycles at 92°C for 30sec, 60°C for 30 sec, 72°C for 1 min. Taq DNA polymerase can polymerize 1000 nucleotides per minute. ATG stop codon wild type PIN3 allele primer 1 primer 2 T-DNA (5 Kb) mutant pin3 allele with the T-DNA insertion primer 1 primer 3 primer 2Explanation / Answer
Answer 1 is 5900bp
Answer 2 is 5400bp
Answer 3 is 500bp
Answer 4 is 900bp
Answer 5 no PCR product because complimentary sequences for primer 3 is not present on wild type
Answer 6 is no PCR product because primer 3 is located in T-DNA region which is not present in wild type
Answer 7. It will produce 2 fragments 5900bp for mutant and 900bp for wild type.
Answer 8 is mutant 5400 and wild type does not have any fragment
Answer 9 is 500 bp for mutant and no fragment for wild type.
note:here one thing should be keep in mind that, 5000bp fregment of T-DNA is only present in mutant and primer 3 is located within this region so every time when primer 3 is given for wild type, it will not give any fragment because sequence for primer 3 is not present on wild type.