Sequencing two strands of dna
I am interested just in the nature of the results as described here.


By aligning this sequence to all nucleotides of all organisms, we would realize that the given (short) sequence occurs in various organisms besides humans. Therefore it might come from a species with only one chromosome see NCBI Blast !

For the sake of the example, let's assume that the species had multiple instances of each chromosome (e.g. one by human mother, and one by human father), and look at "the results as described here". As no detail is given on the protocol, let's further assume the most common scenario - namely that there was no experimental distinction or separation of the individual instances of chromosomes.

Looking at the results, we would realize that is not "next generation sequencing", but Sanger-sequencing.

Now we look at the provided scheme again (note: this is not real experimental data): clearly the bands on the left side only occur for one letter/base, and at a given position of the sequence, there only is one very clear peak on the right hand side (as opposed to the possibility, to have multiple peaks corresponding to different bases).

We would have to conclude that every instance of the chromosome has an absolutely identical sequence. Thus we would conclude that it would not be important to distinguish individual instances.

But wait - aren't maternal and paternal chromosomes different? Absolutely, the given example however only looks at 25 bases rather than the full chromosome - and it would quite possible that they are absolutely identical. (note: there are various experimental techniques to select only specific regions of DNA or RNA for analysis).