Video Transcript
Which of the following is not a use of recombinant DNA? (A) Producing insulin to treat diabetics using bacterial cells. (B) Treating a patient suffering from the genetic disorder thalassemia with bone marrow cells from a healthy donor. (C) Modifying bacterial genomes to produce antigens of pathogens, creating safe vaccines. Or (D) modifying plant genomes to produce crops that are resistant to certain diseases.
This question is asking us about recombinant DNA. So what is recombinant DNA anyway? Recombinant DNA is the combination of DNA from at least two different sources to produce new genetic information. This can be very useful because it lets us introduce useful genes into the genomes of different organisms. The genome is the total amount of genetic information in an organism. So let’s suppose we want to modify the genome of bacterial cells to include the gene for human insulin production. To do this, we need to make recombinant DNA by combining DNA from two sources. So we have the gene for human insulin as one source and bacterial DNA as the other source.
Often, a special kind of bacterial DNA, called plasmid DNA, is used to make recombinant DNA. This is DNA that is separate from the bacterium’s chromosomal DNA and can be introduced to bacterial cells. So this insulin gene is inserted into the bacterial DNA to form recombinant DNA. This recombinant DNA can then be transferred into the bacterial cells, which will then express the insulin gene to produce insulin. The produced insulin can then be extracted and used to treat diabetics. So now, let’s go through these different answer choices to find out which one is not a use of recombinant DNA.
Answer choice (A) states producing insulin to treat diabetics using bacterial cells. As we’ve seen, this is a use of recombinant DNA, so this answer is incorrect. Answer choice (B) states treating a patient suffering from the genetic disorder thalassemia with bone marrow cells from a healthy donor. This is not a use of recombinant DNA since we are simply replacing bone marrow cells with a genetic defect with healthy cells from a donor. We’re not creating recombinant DNA in this process. Therefore, this answer is correct. Although this appears to be the correct answer, let’s just go through these last few choices to be sure.
Answer choice (C) states modifying bacterial genomes to produce antigens of pathogens, creating safe vaccines. This is a use of recombinant DNA because we would need to combine bacterial DNA with pathogen DNA to make recombinant DNA. Therefore, this answer is incorrect. Answer choice (D) states modifying plant genomes to produce crops that are resistant to certain diseases. This is a use of recombinant DNA because we would need to combine plant DNA with a second source of DNA to give the plants resistance. So this answer is incorrect.
Therefore, answer choice (B) is the correct answer because it is not a use of recombinant DNA.
