Most cells in our body are diploid. That is, they contain pairs of the chromosomes (note: treating the Allosome X and Y as a pair for now). Our sex cells (sperm and eggs) are haploid.. That is, they contain only one set of the chromosomes. When talking about DNA matching, some forget there are two sets of chromosomes and are really only referring to the haploid single set of chromosomes.
There is disagreement as to whether X and Y both belong in the haploid definition. When talking about the unique human genome, they do. When talking about the sex cells, they will not both exist at the same time in most cells.
When one hears of "3.2 billion base pairs" in the cell or human genome, they are talking about the haploid. There are actually over 6 billion base-pairs in the nucleus of most cells as most cells are diploid. Autosomal test companies are measuring the diploid and thus the full 6 billion plus base pairs. They report each chromosome as a tuple; sans the sex cells in a male. When quoting numbers and analyzing test results, it is important to understand the difference here and which type of cell and thus DNA is being talked about.
Similarly, there are over 7,200 cMs of measurable, match-able DNA. Most half-identical tools will never report more than half that. Because they ignore the fact there are pairs of the autosome values being returned from the test. So they only report haploid matches. But many regions may be diploid matching and thus should be counted twice.
There is disagreement as to whether X and Y both belong in the haploid definition. When talking about the unique human genome, they do. When talking about the sex cells, they will not both exist at the same time in most cells.
When one hears of "3.2 billion base pairs" in the cell or human genome, they are talking about the haploid. There are actually over 6 billion base-pairs in the nucleus of most cells as most cells are diploid. Autosomal test companies are measuring the diploid and thus the full 6 billion plus base pairs. They report each chromosome as a tuple; sans the sex cells in a male. When quoting numbers and analyzing test results, it is important to understand the difference here and which type of cell and thus DNA is being talked about.
Similarly, there are over 7,200 cMs of measurable, match-able DNA. Most half-identical tools will never report more than half that. Because they ignore the fact there are pairs of the autosome values being returned from the test. So they only report haploid matches. But many regions may be diploid matching and thus should be counted twice.