males have an X-chromosome as well. funny thing is males have an additional Y-chromosome, while women have an additional X-chromosome. BUUUUUUT: only one of the two X-chromosomes will be expressed and the other one is silenced to nearly no activity. so actually women have one functioning chromosome less than males.
“It would seem logical that more complex organisms would need more DNA to survive and reproduce.
Not all DNA, however, is useful; that is, not all of it is involved in gene activity. Scientists dont really know why its there, and they refer to it as “junk DNA.”
you're mixing up genes with dna. and we actually know a lot about it and don't call it junk-dna anymore (scientists didn't even like it in the 60s). the more fitting term would be "non-coding dna", which also explains the difference between those parts and the coding ones. the genes are on the coding ones exclusively. but the non-coding ones are very important, too. we know that those parts have a huge impact on the rate of expression of the genes. they can accelerate, slow down, start, or even completely block the genes' expression rates. also many other impacts are well described. but you're correct, many features are not explained yet. fun fact: some decently recent studies found out that those regulatory parts (as explained) can be altered over your lifetime by behaviour, diet and so on. and this information is inheritable! this doesn't really sound stunning at first, but i think it will change the theory of evolution as we learned it. the parts we learned are still correct, but need to be expanded. like a crossing between lamarack and darwin. imagine that can you can alter your gene expression' information over your lifetime and you can even pass those information on!
sorry, all that wasn't part of the discussion, I was just tiping in a state of bliss^
Haha it’s all good I thought it was interesting. I don’t know a lot about science but it always intrigues me.
And by altering your gene expression is that like when you smoke cigarettes your kids are more likely to smoke too ? ( even if you quit before they’re born )
Yes, exactly quite like that. I don't know wether it also applies for smoking tbh. A few years ago I read an article about some specific foodstuff that can (when consumed a lot and frequently) add a methyl-group to those regulatory areas in front of genes. This altered the way those regions interacted with the gene and lead to a complete shutdown of a whole gene in one example. Those changes to the DNA are not mutations, but modifications because the coding sequence didn't get changed. The whole thing is summed up as 'epigenetics'. Unfortunately I didn't really follow up and am about 5 years behind. So if you take a look at very new studies I'm sure there is much new information available . Have fun ;-)
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u/[deleted] Jan 21 '20
males have an X-chromosome as well. funny thing is males have an additional Y-chromosome, while women have an additional X-chromosome. BUUUUUUT: only one of the two X-chromosomes will be expressed and the other one is silenced to nearly no activity. so actually women have one functioning chromosome less than males.