Break break break!

So, as all teenagers do at 1 AM, I was watching this really cool YouTube video and though it's a little irrelevant at points, the beginning of it has to do with what we're doing in class and it's just really interesting and I figured maybe someone would appreciate it!
http://www.youtube.com/watch?v=BhtgINeaJWg
Enjoy my 50th cousins! (that'll make a lot more sense if you watch the video haha)

When Genetics Get Special

Epistasis: Two different genes work together in harmony to create on phenotype. For example, in labs the genes for melanin production (B for black and b for brown) and deposition (E for deposition and e for no deposition) both help determine what color the lab will be (black, chocolate, or yellow). Black labs are heterozygous or homozygous dominant for both.  Chocolate labs are homozygous recessive for production but heterozygous or homozygous dominant for deposition.  Yellow labs just need to be homozygous recessive for deposition.  With that, you can figure out the genotypes for these dogs and the ratios of breeding and such.

Incomplete dominance: Both alleles in a heterozygous organism may be expressed in the phenotype. Examples include palomino horses and tortoiseshell cats, where having both alleles will make them a new color instead of the color they would be homozygous for either allele (tortoiseshell instead of brown or black)

Codominance: A single gene has more than one dominant allele.  For example, in blood type both types A and B are dominant over type O.  So if you had AO, you would just be type A.  However, if you have both type A and B, you would have type AB blood.  Simple as that.

Sex-linked: A gene is carried only on the x-chromosome, so males are more likely to get the disorder because they only have one X.  An example is colorblindness, which is rare in females but very common in males.  Females are normally only the carriers.

Dihybrids!

So you know that easy peasy Punnett Square thing? Yeah, it gets harder. You can do it with two different traits, for example coat color and walking style.  So you could have a cross between something like CcWW x CCww and have to work it out. There are two ways to do this:
1. Huge, obnoxious Punnett Square: make a large Punnett square with each allele at the top of a column/end of a row, and then do it like you normally would.
2. Make a Punnett square for coat color and one for walking style.  Then multiply together your genotypic or phenotypic ratios (for example, here all of them would have the phenotype for big C, so 4/4, and 3/4 of them would have the genotype CC).  If you wanted to know how many of them had the phenotypes for C and W, then you would do 4/4*4/4 and get 16/16. Okay, bad example.  But still, it's actually pretty simple once you get the hang of it, although it is a lot of work (but what isn't?!)

Mendelian Genetics

Can I call him the mad monk? I mean, I know that's Rasputin but I just like the ring of it.
Anywho, basic Mendelian Genetics involve just a bunch of Punnett Squares, that look like this:

So the mom goes on the top and the dad goes on the side.  Lowercase letters are recessive and uppercase letters are dominant, so you only need one capital letter (dominant allele) to see that trait, but you need two lowercase letters (recessive alleles) to see the recessive trait.  It's actually really simple (I learned it in the 7th grade!). That's all for this exciting post, I promise the next one will be more complicated/exciting!

SNORKS

Today in class we had to take a strand of DNA, transcribe it to mRNA, and then determine what traits our snork would have based on the amino acids that the RNA coded for. We had Snicker Snork, and it came out looking a little...demonic.
But even before we could get to this project, we had to understand protein synthesis, which is how this DNA became visible traits. If you're not quite sure about how that works, here's a quick review.
1 TRANSCRIPTION:
Starting at the promoter (or TATA box in eukaryotes), DNA is unzipped and filled in with RNA polymerase.  This RNA polymerase is single-stranded so it can get out of the nucleus, but it's not quite ready yet.
2 RNA PROCESSING:
This only happens in eukaryotes, but the RNA is fitted with a G cap to protect it and a poly-A tail to stop enzymes in the cytoplasm from digesting any coding nucleotides.
3 TRANSLATION
rRNA in the ribosome. The ribosome reads the mRNA 5'-3' while accepting amino acids from the tRNA, creating a polypeptide chain, and releasing the tRNA. You go ribosome! Also, the tRNA has anticodons which correspond to the codons of mRNA, or groups of 3 nitrogen bases that code for a specific amino acid.
All this out of a little demonic picture. DNA really is pretty cool when you think about it (otherwise it's just confusing!)

ITS GONNA TAKE OVER THE WORLD

So we played around with some E. coli for our lab and added pGLO genes to it.  These genes made it resistant to ampicillin, an antibiotic, and glow under a UV light.  Well, sometimes glow under a UV light.  Since that gene was located behind the arabinose operon, which is inducible, arabinose is needed to be able to code for that protein. Fun, huh? With that sugar, our little bacteria colonies could glow in the dark and not die, so they're gonna take over the world and start a pandemic and wait no, we killed them.  Anyway, they were really cool and I think I get the operon system now! Protein synthesis, that's another story (see awful quiz where I got a 2/10).
But there is so much more on this lab, and it can be found in this huge, comprehensive lab report right here!

Explain! Those! Pictures!

That was supposed to be read in a cheesy game show voice.

The coloration in this flower is due to a mutation in its genes, resulting in its beautiful two colors.  This change in genetics could be due to radiation caused by scientists, or it could be transposons (jumping genes) that worked their way into it's DNA.  Either way, something (from nature to lab experiments) altered this flower's genetics to make it purple and white.

We all have a sonic hedgehog gene that affects the way our limbs grow and how correct they are.  An error with this gene can cause a child to be born with too many fingers, as this baby obviously was.

Survival of the Sickest Chapter 3 CRAP NO

This chapter redefined skin tone and medical conditions that go hand and hand with it and sun exposure
-light skin tone developed in places with limited access to sunlight so they can more easily absorb vitamin D
-speaking of vitamin D, it's super important in helping human survival, from contributing to baby development to cell functions in adults
-cholesterol? yeah, that isn't bad for you like they make it seem, instead it's made and given by the sun, but Northern Europeans and some Africans have too much of it
-folic acid, also absorbed from the sun, is essential to proper cell division and normal body functions
-Asians tend to have the Asian flush when drinking alcohol, as opposed to Europeans who drank alcohol because it was safer than water so they evolved to better break it down
-some diseases may affect certain racial groups more than others because they adapted to different things
Well, here's the actually really fascinating micro-summary of chapter 3. Good night!
SO this post was supposed to be on Your Inner Fish. Shoot. So I read the wrong thing. Oops.
Here's Your Inner Fish.
-the ZPA, which can be affected by Vitamin A, keeps the pinky and the thumb where they should be and makes sure the digits are in working order
-everything on the planet has a Sonic Hedgehog gene, which was discovered because scientists were curious about limb development, so they of course tested on chickens
-it controls how limbs are created in three dimensional space and an error with it can result in more or less digits or other mutations involving arms and hands