I don’t know anything about chromosomes and google is further complicating it for me. I’ve always looked quite different from my peers and I wondered if there was something mixed in with me that would cause that, it turns out I have Scandinavian. In the chromosome breakdown part of the results it says that the Scandinavian is in chromosomes 12 and 21. Can anyone explain to me what this MEANS. Would that affect my physical appearance? Like my facial features? If not, what does it mean?
In: 14
All that means is that you have some DNA that is more common in Scandinavian countries on those chromosomes. There may not be enough to express itself in any of your features.
That is, of course, assuming that the test is accurate in the first place.
When there’s a specific gene for something, we know what chromosome it’s on. Eye color, which is relatively simple, involves at least eight genes across multiple chromosomes, but the most important one is on chromosome 15.
Facial features have too many factors to be on one chromosome. It’s not impossible that there could be some quantifiable difference between people with “scandinavian” 12 and 21 vs 5 and 9, but we don’t know what it is.
You’re you. I hope your peers are genetically diverse and look different from each other, too.
It sounds like you might be hung up on trying to explain your differences. I hope you can embrace yourself for who you are.
Every single human has their sum total of genetic material, their genome, divided across 23 different chromosomes (and then two of each, one maternal and one paternal). Those chromosomes are structured the same way between each and every one of us, barring weird mishaps here and there.
For instance, some given gene may be located on chromosome 12. If it turns out some part of that gene carries a particular mutation in the vast majority of *people of confirmed longtime Scandinavian descent*, you can now go test other people’s genomes, and if they have that same mutation, they likely have some Scandinavian ancestry.
>Can anyone explain to me what this MEANS. Would that affect my physical appearance? Like my facial features? If not, what does it mean?
Nothing like this can be inferred just from knowing the mutation (polymorphism) that they looked at is located on chromosome 12. Knowing the particular gene it is located in would be a first step. If that is given, then you still need to know what that gene encodes, and what the encoded protein does. And going from protein function to “what this means for you as a person” is totally different can of worms, too.
Keep in mind that a ancestry tests are based on databases of people who “say” they’re from certain regions of the globe. There’s not a whole lot of regulation on being able to confirm information or how many people have to be in a database before it’s used. Also Europeans have had many merging of cultures and governments and empires, so one country today had different borders ages ago.
Ancestry tests are fun, but not 100% “scientific”.
But to answer your chromosome question, our DNA isn’t in one long string. It’s in 23 pairs of strings, each one called a chromosome. They’re numbered according to size (this sizing is consistent among humans). Different traits (features, genes) are generated in different parts of our DNA (on different chromosomes).
Which chromosome doesn’t matter it’s just an address of where to find it. A certain blood clotting disorder is on Chromosome X. So if want to see if someone has this disorder, that’s where I want to check – I won’t find this exact disorder on a different chromosome because that’s not where the condition is found.
Imagine your body is like a big instruction book that tells it how to work. Chromosome 12 is like one chapter in that book. It’s a tiny, tiny thing inside your body’s cells that carries important information. Just like a recipe card helps make yummy cookies, chromosome 12 helps make you!
Chromosome 12 exists because our bodies are super complicated, and they need lots of instructions to work properly. It’s like a special code that tells your body how to build and do everything. It’s made up of something called “DNA,” which is like a bunch of tiny beads on a string.
This special chromosome 12 has a job in deciding what you look like and how you work. It’s a bit like how different puzzle pieces make different pictures. The information on chromosome 12 helps your body know things like what color your eyes and hair will be, how tall you might grow, and even some things about your personality.
So, in short, chromosome 12 is a tiny part of you that holds important information, like a recipe for making you. It’s like a puzzle piece that helps create your look and how your body functions.
We have chromosomes which are packages of dna.
When they were first seen it was recognised that we have 23 pairs of these (at least most of us do, there are some conditions that are due to having a specific extra chromosome (eg Down syndrome) or missing a chromosome (eg Turner’s syndrome)). It was then noticed that they are different lengths and this is seen in all people. So to differentiate them, rather than giving them names to tell them apart, it was easiest to number them. The longest pair were tagged as chromosome 1s. The shortest matching pair as chromosomes 22.
They also have similar band patterns when looked at by a microscope which helps differentiate the ones that are similar lengths.
There were then a pair left over. In females these ones looked the same. In males, one was shorter than the other. So rather than a number they got called X and Y. Chromosomes look like Xs so it makes sense to call it. The Y chromosome is much shorter, and when you look closely, on one side of the point there they join is very short. So it got called Y.
Here’s a picture of a set of human chromosomes. It includes an extra set of chromosomes so you can see both XX and XY examples
https://www.genome.gov/genetics-glossary/Karyotype
So for your case, the 12th chromosome is the 12th longest pair
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