Universal Presence of DNA
Key Questions
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Answer:
We are able to isolate DNA from almost all living cells. In addition, the way the DNA is being read and translated into Amino Acids in these cells is identical.
Explanation:
Humans, animals, plants, protozoa, bacteria, and even some viruses carry DNA inside them.
This DNA carries the genetic material or the "blueprint" which guides the cell into producing specific proteins that it needs for its survival and function. This processes is termed the "Central Dogma of Molecular Biology".
It has two major steps:
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DNA Transcription:
The process by which the DNA is transcribed into mRNA to be delivered to the Ribosomes which synthesize proteins in cells. -
DNA Translation:
The process by which the mRNA is translated into Amino Acids and then into proteins by Ribosomes.
These two steps are identical in all living cells. And on top of that, the set of rules for re-writing (translating) the DNA sequence into the language of Amino Acid is the same in all living cells (with a few exceptions for some uncommon Amino Acids).
For example, the DNA sequence that codes for the Amino Acid Lysine will result in Lysine whether that sequence is read by a human cell, a bacterial cell, or a cactus cell.
This proves to us that the DNA provides the same core functional mechanisms to all living cells and that these cells all evolved from the same source.
I hope that answers your question.
References & Further Reading:
DNA
Central Dogma
Transcription
Translation
Ribosomes
Genetic Code -
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I think the best way it relates to evolution is that it shows evidence for common ancestry. After all, the presence of some common feature in every organism on earth is great evidence to support the fact that they all descended from a common ancestor.
However, if you're an intelligent design advocate, then it would point to the common designer theory.
Still, this is a very controversial field, and both sides are in a fierce battle over who's right. Most schools teach just the evolution idea, but if you're at a school that teaches ID, then the ID idea would be handy to know. Either way, unless you want to pursue this in the future, just take what you need to get the grade.
Hope that helped :)