Unknown Story
Текст на Статията
- School is getting tougher. Ugh, you’re so lucky! You’re finding the classes so easy ‘cause your parents passed on their intelligence to you.
- No silly! That is not how it works. There are some things which we develop through our life, like intelligence and somethings we get from our parents....like the color of our hair or the amount of wax in our ears.
- Oh. I did not know that. But how do our parents pass these traits on to us?
- Well, traits like these are passed to us through genes. Most gene comprises of alleles – which is the same DNA differing by a few bases, these can be dominant or recessive. The dominant one is the one that gets expressed in mixed alleles or a heterozygous genotype.
- Right. So for example, the amount of wax in our ears – how do our parents pass on such a trait?
- Okay, so earwax can either be dry or wet, however the wet one is the dominant allele. Every person has two alleles for such genes – one from their mother and father each. Which one each your parents passed on to you is completely random, but we can find out each of your allelic combinations using a pedigree chart.
- Wow, this is a lot to grasp. How does having a different allele actually affect us though?
- Well, genes are basically the expressed alleles are transcripted and translated into proteins, right? So having a specific allele can produce a specific protein which works in a certain way. Going back to the earwax example, if you inherit the allele for wet earwax, then a certain protein will be produced which ensures that your earwax is wet. It’s the same with genetic diseases.
- Oh! Then I have one last question for you! I have cystic fibrosis, which the doctor said is a recessive condition. But my parents say they have never experienced the symptoms. How can they pass on a condition to me that they never had?
- Ah yes, that is possible. So you have the disease, which means your genotype for it is cc – C stands for cystic fibrosis. If your parents claim to have not had it, but could pass it on to you, it means they are a heterogenous carrier – they both have the genotype Cc. So when you were born, it was just bad luck that both recessive alleles got passed onto you, which is why you have the disease.
- Woah! If they’re carriers, is there a chance that they will develop it in the future?
- Wow! That is really relieving. And interesting, to be honest!
- No, this condition occurs only if you have two recessive alleles. Both your parents have one dominant and one recessive allele so only the dominant one gets expressed and transcripted. So they can never be affected by such a disease!
Над 30 милиона създадени разкадровки
Без Изтегляния, без Кредитна Карта и без Регистрация, за да Опитате!
