How do the Roloffs from "Little People, Big World" have three normal sized children?
The are both dominant for dwarfism. If they have normal sized kids then the must also have recessives as well (i.e. heterozygous - Dd). So with each birth (using a Punnet square), they have a 25% chance of having a homozygous dominant child (DD), a 25% chance of having a homozygous recessive child(dd - this child will NOT be a dwarf), and a 50% chance of having a heterozygous dominant child (Dd). The could have had 10 normal kids if those were the genes that got passed down. So, apparently their 3 normal kids all got a recessive from each parent so they are dd. The odds were low but it so random it can happen. Their twins are fraternal since one is DD or Dd and the other is dd. So two eggs were fertilized by 2 different sperm carrying different genes. Its all pretty random and its more far complicated than I've laid out but this gives a basic idea.
Epigenetics?
Can someone give me an outline of the molecular mechanisms behind why DNA Acetylation, Methylation, Phosphorylation and general structure (i.e. nucleosomes etc) affect genetic expression/transcription etc? I get how these changes take place, but not how they affect phenotypes. Any accessible webpages would also be a massive help. Thanks everyone!
If you set a Guinness World Record, do they pay you money?
No. However, if you set an official world record you will undoubtedly benefit financially from the exposure that you will gain. The Guinness organisation itself pays professional adjudicators, editors etc who are in turn payed from sponsorship and advertisement revenue associated with the Guinness brand.