MedGen

OD is optical density which refers to the absorbance per unit of length, which in most cases is 1, i.e. the distance through which the light has to pass through the sample. If you are using a typical 1cm cuvette then it is equal to the absorbance. It is possible to put all three curves on one graph with Excel, I think you have to select a line graph and put them in as 3 separate samples (in the X variable box). The only problem is that you don't get a smooth curve, which sucks. Alternatively draw it by hand.

Your best bet to start off with is to familiarise your self with the basic tenets of Mendelian Inheritance, I'm sure your school library should stock some books on the subject. As for websites, as much as I hate to recommend it I would perhaps try Wikipedia and follow the references there. Alternatively google "genetics education resources", I'm sure that'll turn a few hits to keep you busy for a while. If you have specific questions then feel free to ask away, the chaps and chappettes on this forum are well clued up on pretty much anything.

At a young age I always entertained the typical boyhood fantasies of being an astronaut or archaeologist. That soon changed into wanting to be a vet which I carried on with from around 10 right through to about 18. Unfortunately I screwed up college (British college) and flunked my A levels. For a few years I didn't know what I wanted but settled on being a chef as I'd convinced myself I simply didn't have the brains to do anything intellectually based. That all changed about 3 or 4 years ago when I started to read New Scientist and realised I could actually follow what they were talking about. I considered medicine for a while, but knew that I wasn't doctor material, I don't like people enough, so I went into genetics which I'm currently studying now. When I first started uni I thought I'd want to go into cancer research, and a little part of me still does, but I'm not so sure that the cure for cancer lies in genetics any more. Currently I'm trying to find a way to marry post-doc research with clinical science. It's recently dawned on me that we need to develop some accurate diagnostics for complex disorders that contain major genetic elements, including cancer and CHD. I still entertain my delusions of grandeur of holding a professorship in Human Genetics at a major institute with a Nobel prize under my belt that will some how radically change the way we treat and diagnose genetic diseases. I'm sure that will change over time though, but I'm sticking with genetics, its too interesting not to continue with.

That's pretty awesome. It'd be nice to see them getting more access to other journals in the future.

Just to say thanks for the suggestions, we ended up going with Phire, Phusion, KAPA Hifi and a standard Taq. Turns out the Phusion from Finnzymes worked best, plus we've already got some more in the freezer.

Just a quick question for the practising biologists on the forum. I've just started a research project and will be performing some nested PCR on a 4kb sequence that will be genotyped in a number of individuals (~50 initially). Does anyone know, off the top of their heads, of a high fidelity polymerase that is capable of performing long PCR's? I'm going to be testing some pre-designed primers and such, and all the other reagents and thermal profile are going to be tested empirically so they aren't an issue right now. Cheers in advance.

That might be because most people don't the difference between type 1 and type 2 diabetes, I agree though it is a common misconception and must be freaking annoying. I get a little peeved when DNA is portrayed as being like a computer, seriously it's about as much like a computer as I am the Queen of freaking England.

First bit of advice is go and see your GP about it. As has already been pointed out it is most likely a case of an ingrown hair that is infected. I've suffered from a similar affliction, thankfoully not in the same place though! If there is what looks like a pore or a darkened area then it may well discharge itself within a few days. However, and I this is a very important point to remember: GO SEE YOUR DOCTOR ABOUT IT I know it can be embarrassing, but not as embarrassing as having a recurring problem with your John Thomas.

Mostly because of problems with genomic imprinting. I don't think there are any human parthenotes in existence, most of the research has been carried out in animal models.

Done, I understand you had to lump atheism under religions, but I've explained things where necessary.

I think an interesting development in our eating habits was cooking meat rather than just eating it raw. I expect it has some basis in destroying parasites and other pathogens, thus being safer to eat. Does anyone have any idea how this developed though? I assume it came after fire was discovered obviously, but did start our culturally then spread?

Oh okay, got that impression from a previous thread, I just didn't want the OP to think that it was a valid answer and go away with some utter bunkum filling his head. Thanks for the pointer, I'll remember it for the future.

Sorry, my "what" was in reference to your word salad. It made no sense whatsoever, and in fact I would go so far as to call it pseudoscience. Not to mention such spurious claims as this: No, quite simply, the energy released by the hydrolysis of the high energy bonds between the phosphate groups in ATP is nowhere the same as that of a typical hydrogen bond, different bond energies altogether.

What? Water is very important for enzyme catalysed reactions, but mostly where water molecules in the enzyme active site help to stabilise the other non-covalent interactions that allow for the ES complex to exist for long enough for the enzyme to reduce the activation energy for the ES complex state. The hydration shell around the polymerases doesn't seem to play an important part in the enzymes activity, but is essential for it to remain in solution, particularly in high salt/sugar environments (see halophiles).

If you mean instead of a DNA primer, then the reason is that the DNA polymerases that catalyse second strand synthesis simply cannot start working from scratch, they require a primer to do this. RNA polymerases however do not, thus you get a primer for a DNA polymerase made of RNA. It may also have evolved as a part of the proofreading mechanisms inherent in DNA replication, not to mention all those endonucleases floating around could quite easily just come along and degrade a DNA primer, then you wouldn't get any replication! I'm sure there's more to it than that, maybe one of our resident experts can fill in the rest.

I'm not entirely sure that humanities taxonomic classifications are really the reasoning behind the ability of certain species to interbreed successfully. I think chromosome number is only a short part of the answer. Cytogenetically speaking it probably more of an issue of the regions that pair up during metaiphase. Using the human chromosomal fusion in our prehistory, there occurred a fusion between what is now the chimpanzee autosomes 12 and 13 (I think it was those two) to generate our second chromosome. Obviously if this only occurred in a single individual then how does it spread? Because of the nature of the fusion, end to end at the telomeres, the requisite regions that align are not disrupted, so there is no barrier to breeding here. Also there is the time since the two species MRCA, most likely with Lions and Tigers this was not so far back as to prevent the odd hybridisation, although has this occurred in the wild, or merely through human intervention? Interestingly horses and donkey's diverged further back in evolutionary time than humans and chimpanzee's, makes you think?

That's a little general. There are hundreds of thousands of articles on each of those sites for each area of medicine or biology.

For open-access your best bet is PLoS, as linked above. Alternatively you can try Google scholar, it usually throws up a few good results. Ultimately though I would say PubMed is the gold standard for biology and medicine related journal articles: PubMed Central If you do not have experience reading technical journals then they can be a real handful as they assume a certain level of understanding and knowledge, i.e. to the level that the authors are.

Creationism is not science, intelligent design is not science. They bring no evidence to the table at all, their claims have been refuted numerous times throughout the last 150 years because...they have no evidence. There is nothing in observational reality that has been observed that can be used to support the claims of creationists and ID proponents and their wack conjectures. They are not scientific theories, they have no applications, they make spurious predictions, and most of all they are unfalsifiable. The theory of evolution however has every biological field of science supporting it from ecology to paleontology, even right down to the molecular sciences of molecular biology, genetics and biochemistry. What is the likelihood that ToE is bunk when it has every aspect of biology supporting it? Last year alone there were some 18,000 peer reviewed journal articles published throughout the world in reputable journals in support of evolution, for creaitonism? None.

Especially so, horrible man climbs down peoples chimney's ever year! Bugger knows what he intends...evil man.

Oh I know, I'm glad it was even mentioned to be honest, its often overlooked completely, maybe he'll introduce it a little more in episode 2 which is about human evolution. That should bring the creationists out of the woodwork a little more.

I couldn't keep something like this all to myself, that would just be selfish! Any thoughts, aside from the possible remarks about creationist children? Personally I was hoping for a little more historical context, I don't know a massive amount about Darwin himself, except for his penchant for worms and pigeons perhaps. I would have like to see a little more emphasis on the molecular evidence for evolution too, after all, even without fossils that alone would establish evolution as a fact. Still two more episodes to go, so there's still hope.

It should be available here: Google Video: Genius of Charles Darwin