If source DNA is extracted from a eukaryotic organism and used to create transgenic bacteria, why will the mRNA transcribed from the recombinant DNA encode a defective protein in the bacteria?Multiple choice question.Eukaryotic DNA contains introns, which bacteria cannot remove.Bacterial DNA only contains introns, and so bacterial enzymes do not recognize the exons present in eukaryotic mRNA.Bacteria do not use the same genetic code as eukaryotes do.Eukaryotic DNA only contains exons, and the mRNA made from it will not be able to be translated by bacterial ribosomes.
Question
If source DNA is extracted from a eukaryotic organism and used to create transgenic bacteria, why will the mRNA transcribed from the recombinant DNA encode a defective protein in the bacteria?Multiple choice question.Eukaryotic DNA contains introns, which bacteria cannot remove.Bacterial DNA only contains introns, and so bacterial enzymes do not recognize the exons present in eukaryotic mRNA.Bacteria do not use the same genetic code as eukaryotes do.Eukaryotic DNA only contains exons, and the mRNA made from it will not be able to be translated by bacterial ribosomes.
Solution
The correct answer is "Eukaryotic DNA contains introns, which bacteria cannot remove."
Here's why:
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Eukaryotic DNA is composed of both exons (coding regions) and introns (non-coding regions). During the process of transcription in eukaryotes, these introns are removed in a process called splicing, and the exons are joined together to form the mature mRNA.
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Bacteria, being prokaryotes, do not have introns in their DNA. Therefore, their transcription machinery does not have the necessary mechanisms to remove introns from the transcribed mRNA.
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If a eukaryotic gene (containing both exons and introns) is inserted into a bacterium, the bacterium will transcribe the entire gene, including the introns. This results in an mRNA molecule that contains sequences (the introns) which should not be there.
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When this mRNA is translated into a protein, the intron sequences will be translated along with the exon sequences. This will result in a protein with extra amino acids, which can disrupt its structure and function, making it defective.
So, the inability of bacteria to remove introns from eukaryotic DNA is what causes the production of defective proteins.
Similar Questions
How does mRNA transcribed from bacterial DNA differ from mRNA transcribed from eukaryotic DNA?Multiple choice question.Only bacterial mRNA contains introns.Only eukaryotic mRNA contains introns.Only eukaryotic mRNA encodes amino acids.Only bacterial mRNA encodes amino acids.
How do researchers prepare an intron-free copy of a eukaryotic gene for use in creating transgenic bacteria?Multiple choice question.use taq polymerase to generate thousands of copies of the gene of interestestablish a clone library then expose clones to a probe that contains the DNA of interestuse reverse transcriptase to make cDNA from mature mRNAuse restriction enzymes to cut up both source DNA and vector DNA
What happens if the mRNA did not transcribe properly?
Prokaryotes and eukaryotes differ in how they accomplish transcription and translation. Which of the following are unique to prokaryotic cells?SELECT ALL THAT APPLYMessenger RNA must travel out of the nucleus to reach a ribosome for translation.Uses a lot of cellular energy.Transcription occurs in the cytoplasm.RNA must be spliced after it is transcribed before it can be translated.Main enzyme is RNA polymerase.Translation of an RNA sequence can begin before transcription is complete.
Why might it be advantageous for bacteria to prevent transcription of a particular enzyme, unless its substrate is present in the environment?Multiple ChoiceTranscription is the last stage of gene expression and is therefore more easily regulated.Several types of RNA are required for transcription to proceed, and often they are not available.DNA is not used during transcription, and thus avoiding transcription protects the DNA from mutation.The steps involved in synthesizing proteins such as enzymes require a considerable amount of energy.
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