Question

This one is about GM food experiment. Please help me complete these two pages.

Why did we look for the gene for tubulin as well as the gene for the 35S promoter? 20) Below is a gel from the GM food experiment. Use it to ans Wild-Type Soy Roundup Ready Soy Food Product 1 Food Product pBR Tubulin 35S Tubulin 35S Tubulin 35S Tubulin 355 12

Answer 1

19. We looked for the gene for Tubulin in order to guarantee that our PCR procedure is effective for each sample. Tubulin is a positive control as it is a protein found in all food and soy products.

We looked for the gene for 35S promoter as GM (Roundup Ready) soybean will always have a 35S promoter.

20a. Presence of Tubulin band served the purpose that whether or not the food product samples contains the DNA. Tubulin is a protein found in all living cells and therefore if the sample contains tubulin DNA than it guarantees successful PCR.

20b. The negative control is a control in which no result response is expected. Here we are searching for GM food so wild type soy is a negative control as it will show no response for genes associated with genetic modification.

In case of positive control, the known response is expected so Roundup Ready Soy is a positive control.

20c. Food product 1 test positive for genetic modification because of the presence of both tubulin and 35S gene in the DNA.

21.

	Tubulin	35S	Explanation
a	Absent	Absent	Since tubulin is absent which means PCR is not accurate for the sample.
b	Absent	Present	Tubulin absent means PCR is unsuccessful. While 35S band presence in the absence of tubulin indicates some experimental error as it's not possible.
c	Present	Absent	Tubulin present but not 35S means its a wild type crop.
d	Present	Present	Both genes are present indicating GM soy crop