What does "sequencing a species' DNA mean", what does that serve to?

And by the way, in that process, what is being 'sequenced'?

2 Answers

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  • Ted K
    Lv 7
    1 month ago

    For any species, its DNA contains its genetic code--the blueprint for every structure and biochemical process and mechanism occuring in that species.  The DNA "sequence" refers to the order of chemicals  called "bases," which comprise the business end of a molecule of DNA.  When a species' DNA is "sequenced," that means its base sequence (order) is being determined.  DNA is essentially a long string of these bases in varying order.  There are 4 bases--adenine, thymine, guanine and cytosine (ATGC), and their order turns out to be a code for the order of amino acids in proteins.  So, every protein's amino acid sequence is encoded in the sequence of bases in the gene (DNA) for that protein.  In addition, there are large sections of DNA that do NOT code for proteins, instead, some of these portions are involved in control and regulation of gene expression.  Still other portions have as yet unknown functions, some may be evolutionary "junk."  But sequencing an organism's DNA sequence (its genome), can tell us a lot about that species, including how it differs from other species.

      Fred Sanger developed the first reliable method for DNA sequencing in the early 1970s, an achievement which snagged him his second Nobel prize.  Early methods were laborious and slow, technology developed during the Human Genome Project, which ran from about 1990-2000, has made DNA sequencing automated, fast, and inexpensive.  Many known species have now had their DNA sequences determined.

  • Anonymous
    1 month ago

    DNA is a long molecule made up of a string of nucleotides. There are 4 different nucleotides, and a codon, which is a sequence of 3 of the nucleotides encodes an amino acid. The DNA molecule is so long that it contains millions, even billions of codons.

    Sequencing the DNA means figuring out what the DNA of an animals contains, in terms of the arrangement of these codons. These codons contain the genetic information that is unique for a species.  Closely related species such as the chimpanzee and the gorilla share many similarities in their genes. Therefore if we sequence the DNA of a species and compare it to the sequences of other species, we may be able to figure out how closely related they are.

    Besides evolutionary relationships, we can use DNA sequences to figure out where a gene may be located. That gene may be used to make a particular protein that we are interested in. For example, if we can identify the gene that makes vitamin C, we can possibly copy the gene onto, say, bacteria, so that bacteria that have that gene will make vitamin C. Using bacteria to make vitamin C can be a lot cheaper than extracting it from food for example. Scientists have also sequenced the DNA of viruses to figure out what kind of proteins the virus use to enter cells. Right now, after we have sequenced the genes of the Covid-19 virus, scientists are trying to use the information to make a vaccine that can neutralize the virus. Sequencing have also led to cures for genetic diseases, by figuring out which genes are abnormal, doctors can try to insert a normal copy of the gene into a person using a technique called CRISPR.

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