A question on biology

[tobee]

I'm currently listening to a podcast about a case in America about a murder of a young woman whose body was burned.

In discussion about the case, the presenter and the legal experts he is talking to remark on the possibility of dna that might be found. And there being either male or female dna. Obviously, I know about xx and xy chromosomes, difference in sex organs etc. Can anyone tell me about the difference between male and female dna?

This seems further proof against the bullshit about being "assigned at birth", and would possibly be helpful as a tool for argument. Thank you.

Actually, could someone clarify, is the chromosome argument the same as dna? I failed biology o level.

Chromosomes are made of DNA.
They are referring to XX and XY as you said.

Just as well I asked on these boards then!

As Barracker said. Chromosomes are made from DNA. It's the DNA sequence that is looked at in DNA analysis, and there are sequences only found on the Y chromosome that are looked for in tests. If you find evidence of a Y chromosome then you know it's not female DNA.

As EndoplasmicReticulum said, they can find DNA sequences unique to males. There are some potential sources of error, eg. If the person has a deletion of the sequence(s) being tested, a pregnant woman carrying a male foetus, if someone has had a bone marrow transplant. I suspect some intersex conditions may throw a spanner in the works too, but not the more common ones.
I shouldn't have to say this, but the source DNA can tell you nothing interesting about the gender identification of the person it came from.

Chromosomes are the tidy packaging for the DNA strands.

It's a bit like when you buy a packet of noodles. When it's all solid and dry that's the chromosome and when you cook it. The stands separate out being the DNA.

Endoplasmicreticulum are you rough or smooth?

I have ribosomes.

Oh wow! Thanks for the answers.

Apart from some blood cells, every cell of your body contains DNA. Human DNA is 23 pairs of chromosomes. One of these pairs is the sex chromosomes - XX for women, XY for men.

Each cell (apart from the blood cells) has at least one nucleus, and each nucleus has a full set of DNA - the 23 pairs of chromosomes. An adult human has about 75 trillion cells, excluding the blood cells. Some cells have more than one nucleus. So there are at least 80 trillion pairs of sex chromosomes in your body. Every single cell is identifiable as male or female from its DNA.

By contrast, there are no definitive differences between the races. A single cell from a human body would tell you whether it came from a man or woman, but you couldn't tell the race. You might be able to make an educated guess: genes for black, straight hair are more likely to come from a Korean than an Norwegian but you wouldn't know for sure.

Yes. DNA is the compound that chromosomes are made up of. Humans have 23 pairs. 22 pairs are two of the same (one containing genes from the mother and the other containing genes from the father) but the last pair of chromosomes are the sex chromosomes. They can either be an X chromosome (women have xx chromosomes so the mother will always pass on an X chromosome) or a shorter Y chromosome (only fathers can pass on a Y chromosome because only men who have xy gave one). Because the Y chromosome is shorter is has less dna. This makes men more susceptible to some genetic defects (e.g. hemophellia) because they will only have one set of genes for that disease (which means that if they have the recessive gene that causes the gene they won’t have the dominant gene which suppressed its expression) in contrast women who have two xx chromosomes will often carry such diseases without being affected by them because they are heterogenous for the disease.

I don't think these answers would go down well with trans activists.

Thank you for these replies, lovely and clear!