Concepimento

Gemelli eterozigoti: chi sono e differenze con omozigoti

gemelli eterozigoti

Gemelli eterozigoti

Quando da una stessa gravidanza nascono due o più fratelli, si parla di gemelli. Le gravidanze gemellari non sono molto comuni, considerando che costituiscono solo circa l’1,5% di tutte gravidanze. La predisposizione ad avere gemelli sembra essere dovuta soprattutto a fattori ereditari (da parte materna), in quando la loro nascita è più frequente nelle famiglie in cui ci sono stati già altri parti gemellari. Altri fattori che sembrano incidere sono la razza (le gravidanze gemellari sono più numerose tra le persone di colore, minime in quelle orientali) e l’età della madre (più l’età è avanzata, più è alto il livello di ormone FSH e maggiore è la disponibilità di ovuli da fecondare). Negli ultimi anni le nascite di gemelli sono aumentate, sia proprio a causa dell’innalzamento dell’età media delle mamme, sia in seguito al sempre più diffuso ricorso a cure per la fertilità e alla fecondazione assistita. I gemelli, comunque, non sono tutti uguali, ma si distinguono in:

  • gemelli eterozigoti (chiamati anche bizigoti, bicoriali o biovoulari),
  • gemelli omozigoti (chiamati anche gemelli monozigoti, monocoriali o monoovulari).

Vediamo nei dettagli quali sono le differenze tra gemelli omozigoti ed eterozigoti.

Gemelli eterozigoti: chi sono

I gemelli eterozigoti sono, per dirla in parole semplici, i gemelli diversi. I gemelli eterozigoti, pur essendo nati dalla stessa gravidanza, non condividono lo stesso DNA, quindi non hanno lo stesso gruppo sanguigno, non sono identici ed è possibile avere gemelli eterozigoti maschio e femmina. Ciò avviene perché i gemelli bizigoti, come dice il loro stesso nome, non si formano a partire dallo stesso zigote (la cellula che deriva dall’unione di spermatozoo e cellula uovo), ma da due o più cellule uovo diverse, che vengono fecondate quasi in contemporanea da due o più spermatozoi. In rarissimi casi, è possibile anche la nascita di due gemelli eterozigoti con padri diversi, a seguito della fecondazione di due diversi ovociti a breve distanza di tempo, ma in due rapporti distinti.

gemelli eterozigoti maschio femmina

Gemelli omozigoti ed eterozigoti: differenze

I gemelli eterozigoti, come abbiamo visto, derivano da due diversi zigoti e questa è la prima differenza con i gemelli omozigoti, che invece si formano a partire dallo stesso zigote. I gemelli eterozigoti non condividono placenta e cavità amniotica, cosa che può invece succedere in caso di gemelli omozigoti. La differenza sostanziale tra gemelli omozigoti ed eterozigoti sta quindi nel DNA: i primi hanno lo stesso DNA e per questo sono identici tra loro e sono sempre dello stesso sesso; gli eterozigoti, invece, non hanno lo stesso patrimonio genetico e quindi avere gemelli eterozigoti maschio e femmina è possibile.

Articolo PrecedenteProssimo Articolo

733 Comments

  1. Taxi moto line
    128 Rue la Boétie
    75008 Paris
    +33 6 51 612 712  

    Taxi moto paris

    Aw, this was a really good post. Taking a few minutes and actual effort to make a superb article… but what can I say… I procrastinate
    a lot and never manage to get anything done.

  2. Magnificent web site. Plenty of helpful information here. I am sending it to several buddies ans also sharing in delicious. And certainly, thanks for your sweat!

  3. I simply could not leave your web site before suggesting that I really enjoyed the standard info an individual supply for your visitors? Is gonna be again steadily to inspect new posts

  4. wonderful points altogether, you simply gained a new reader. What would you suggest in regards to your post that you made a few days ago? Any positive?

  5. Wonderful blog! I found it while browsing on Yahoo News. Do you have any suggestions on how to get listed in Yahoo News? I ave been trying for a while but I never seem to get there! Cheers

  6. It as rather a great along with handy part of details. I will be satisfied that you simply contributed this convenient info about. Remember to keep us informed this way. Appreciate your spreading.

  7. It as really a cool and useful piece of information. I am glad that you shared this helpful info with us. Please keep us informed like this. Thanks for sharing.

  8. That is a really good tip particularly to those fresh to the blogosphere. Brief but very precise information Thank you for sharing this one. A must read article!

  9. I’а†ve learn some good stuff here. Certainly price bookmarking for revisiting. I surprise how so much effort you place to make the sort of great informative website.

  10. Wow! This could be one particular of the most useful blogs We have ever arrive across on this subject. Actually Wonderful. I am also an expert in this topic so I can understand your effort.

  11. You have noted very interesting points ! ps decent site. What a grand thing, to be loved What a grander thing still, to love by Victor Hugo.

  12. I was suggested this website by my cousin. I am not sure whether this post is written by him as nobody else know such detailed about my trouble. You are incredible! Thanks!

  13. This unique blog is without a doubt entertaining and factual. I have picked many handy tips out of this source. I ad love to go back over and over again. Thanks a lot!

  14. I think this web site holds some rattling superb info for everyone . аЂа‹The ground that a good man treads is hallowed.аЂа› by Johann von Goethe.

  15. I simply want to say I am new to blogging and actually savored your web site. More than likely I am going to bookmark your site. You surely have wonderful writings. Regards for revealing your blog.

  16. Usually I do not learn article on blogs, but I wish to say that this write-up very pressured me to try and do it! Your writing style has been surprised me. Thank you, very great article.

  17. Your great competence and kindness in maneuvering almost everything was essential. I usually do not know what I would ave done if I had not encountered such a subject like

  18. I will immediately seize your rss as I can not find your e-mail subscription hyperlink or e-newsletter service. Do you have any? Please permit me realize in order that I may just subscribe. Thanks.

  19. This particular blog is obviously interesting as well as amusing. I have discovered a bunch of handy tips out of this source. I ad love to visit it over and over again. Cheers!

  20. Wow! This could be one particular of the most helpful blogs We ave ever arrive across on this subject. Actually Wonderful. I am also an expert in this topic therefore I can understand your effort.

  21. Ia??a?аАа’аАТ‚аЂ ve read some good stuff here. Definitely price bookmarking for revisiting. I surprise how so much effort you place to make this sort of magnificent informative website.

  22. It’а†s in reality a great and helpful piece of information. I am satisfied that you just shared this helpful info with us. Please keep us up to date like this. Thanks for sharing.

  23. Sweet blog! I found it while surfing around on Yahoo News. Do you have any suggestions on how to get listed in Yahoo News? I ave been trying for a while but I never seem to get there! Thanks

  24. That is a great tip particularly to those new to the blogosphere. Short but very precise info Appreciate your sharing this one. A must read post!

  25. Wow! This can be one particular of the most beneficial blogs We have ever arrive across on this subject. Basically Great. I am also a specialist in this topic so I can understand your hard work.

  26. It as nearly impossible to find well-informed people in this particular subject, however, you sound like you know what you are talking about! Thanks

  27. Pretty nice post. I just stumbled upon your blog and wanted to say that I ave truly enjoyed browsing your blog posts. After all I will be subscribing to your rss feed and I hope you write again soon!

  28. Usually I don at read article on blogs, however I wish to say that this write-up very compelled me to take a look at and do it! Your writing taste has been amazed me. Thank you, quite nice post.

  29. I was recommended this blog by my cousin. I am not sure whether this post is written by him as no one else know such detailed about my difficulty. You are amazing! Thanks!

  30. Thank you, I ave recently been looking for info about this subject for ages and yours is the greatest I ave discovered till now. But, what about the bottom line? Are you sure about the source?

  31. Wow, marvelous weblog structure! How lengthy have you ever been blogging for? you made running a blog glance easy. The whole look of your website is magnificent, let alone the content!

  32. Modular Kitchens have changed the idea of kitchen nowadays because it has provided household ladies with a comfortable yet a sophisticated space in which they will invest their quality time and space.

  33. My brother suggested I might like this website. He was totally right. This post actually made my day. You cann at imagine simply how much time I had spent for this information! Thanks!

  34. Very nice post. I just stumbled upon your blog and wanted to say that I ave truly enjoyed browsing your blog posts. In any case I all be subscribing to your feed and I hope you write again soon!

  35. I think other web-site proprietors should take this web site as an model, very clean and excellent user friendly style and design, let alone the content. You are an expert in this topic!

  36. I’а†ve learn several excellent stuff here. Certainly worth bookmarking for revisiting. I wonder how a lot attempt you set to make the sort of wonderful informative web site.

  37. You are my inhalation, I own few web logs and sometimes run out from post . No opera plot can be sensible, for people do not sing when they are feeling sensible. by W. H. Auden.

  38. Thank you a lot for sharing this with all folks you really recognise what you are talking about! Bookmarked. Please also talk over with my website =). We may have a link alternate contract among us!

  39. We stumbled over here from a different web page and thought I might as well check things out. I like what I see so i am just following you. Look forward to checking out your web page repeatedly.

  40. I think other web site proprietors should take this website as an model, very clean and magnificent user friendly style and design, as well as the content. You are an expert in this topic!

  41. [url=http://valacyclovir.shop/]valtrex without prescription[/url] [url=http://buysynthroid.shop/]generic synthroid[/url] [url=http://phenergan.shop/]phenergan cream[/url] [url=http://buyantibiotic.shop/]how to get minocycline[/url] [url=http://acyclovir.shop/]buy zovirax cream online no prescription[/url] [url=http://ivermectin.republican/]stromectol order online[/url] [url=http://atrazodone.online/]trazodone 80 mg[/url] [url=http://buylisinopril.shop/]prinivil 10 mg[/url]

  42. [url=https://silagra.cfd/]silagra online[/url] [url=https://trazodone.golf/]trazodone 300 mg cost[/url] [url=https://buyvaltrex.shop/]how much is valtrex generic[/url]

  43. [url=http://clonidine365.com/]clonidine brand name in india[/url] [url=http://trazodone.golf/]trazodone 100 mg[/url] [url=http://bactrim911.com/]order septra online[/url] [url=http://buycialis.shop/]cialis viagra[/url] [url=http://silagra.cfd/]silagra tablets[/url] [url=http://propranolol365.com/]inderal buy online usa[/url] [url=http://avodart.agency/]avodart 0.4 mg[/url] [url=http://buycephalexin.monster/]keflex europe[/url]

  44. [url=https://amoxil.cfd/]augmentin 500 mg 125 mg tablet[/url] [url=https://mebendazolevermox.shop/]vermox tablets nz[/url] [url=https://escitalopram.online/]lexapro otc[/url] [url=https://propranolol.email/]propranolol 10mg[/url] [url=https://clonidine.guru/]clonidine 0.025 mg[/url] [url=https://doxycyclinepill.com/]buy doxycycline[/url] [url=https://tetracycline.store/]tetracycline orders without a prescription[/url] [url=https://buytrazodone.monster/]trazodone online pharmacy[/url] [url=https://retinoa.store/]retino 0.025 cream[/url] [url=https://buyzofran.shop/]zofran tablets cost[/url]

  45. [url=https://tadacip.golf/]tadacip 60 mg[/url] [url=https://buyfildena.shop/]fildena 100 online india[/url] [url=https://cipro.golf/]ciprofloxacin 250 mg tabs[/url] [url=https://buyprozac.shop/]prozac india cost[/url] [url=https://zanaflex.cfd/]503 tizanidine 4mg[/url]

  46. [url=https://albenza24.com/]where to buy albendazole[/url] [url=https://tadacip.golf/]tadacip 60 mg[/url] [url=https://lisinopril2022.com/]lisinopril online canada[/url] [url=https://cephalexin.boutique/]cephalexin without prescription[/url] [url=https://buyfildena.shop/]fildena 100 online india[/url] [url=https://toradol.shop/]toradol brand name[/url] [url=https://onlinepharmacy.email/]best rated canadian pharmacy[/url] [url=https://motilium.shop/]motilium domperidone[/url] [url=https://nexium.store/]nexium discount prices[/url] [url=https://cipro.golf/]ciprofloxacin over the counter usa[/url]