Genomic DNA from a mouse is isolated, fragmented, and denature...

Question

Genomic DNA from a mouse is isolated, fragmented, and denatured into single strands. It is then mixed with mRNA isolated from the cytoplasm of mouse cells. The image represents an electron micrograph result showing the hybridization of single-stranded DNA and mRNA. Based on this electron micrograph image, how many introns and exons are present in the mouse DNA fragment shown? <>

Accepted Answer

Hey, everyone. Let's take a look at this question together. Doctor Eib wants to determine the number of introns and exxons in the human insulin gene. He isolated a segment of genomic DNA from a human somatic cell fragmented and denatured it into single strands and mixed it with a specific M R N A obtained from the cytoplasm of beta cells of the pancreas. After analyzing the hybridization pattern, he found that the DNA segment is hybridized to the M R N A at three sites while it remains un hybridized at two sites. So can you tell what is the likely number of introns and exxons in the human insulin gene? Is it answer choice? A, the human insulin gene has one Enron and two exxons. Answer choice B. The human insulin gene has two enrons and three exxons. Answer choice C. The human insulin gene has three introns and two exxons or answer choice. D the human insulin gene has four enrons and five exxons. Let's work this problem out together to try to figure out how many introns and exxons are present in the human insulin gene. So based on the hybridization pattern, we know that the DNA segment is hybridized to the M R N A at three sites and un hybridized at two sites. And so E M R N A is hybridized at three sites which indicates that the human insulin gene has three exxons. And so the M R N A which is un hybridized at two sites indicates that the human insulin jeans has two introns. Since those two un hybridized sites correspond to the introns not present in that M R N A. And so we have two enrons and then the M R N A is hybridized at three sites. So we have three exxons. So in total, we have three axons and we have two introns, which means that answer choice. B the human insulin gene has two enrons and three exons is the correct answer. Since we know that the M R N A is hybridized at three sites and that corresponds to those three exons. And the M R N A is un hybridized at two sites which corresponds to those two introns found within the human insulin gene. So we have three exxons and two introns making answer choice. B the likely number of introns and exxons in the human insulin gene. So it is the correct answer. I hope you found this video to be helpful. Thank you and goodbye.

Key Concepts

Introns and Exons

Hybridization

Electron Micrography

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