h2whoa
Ace2whoa - resident geneticist
- Sep 21, 2004
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Basic biology, my friends. It gets you places.
Hi, nice to meet you

I just wanted to correct something in your post. Obviously we differ on our theistic viewpoints, but I have no axe to grind with theistic evolutionists! I'm not anti-Christian, just anti-Creationism.
Deoxyribonucleic acid, or DNA as you know it is the genetic code for all organisms. This is correct. This contains basic information about our bodies- what weaknesses and strengths we inherited from our parents- this ranges from illnesses to the color of your hair. For example, if one parent has brown eyes and the other has blue, the child has a very likely chance of having brown eyes. This is because blue eyes are a hereditary gene. Simple genetics lesson for anyone listening. And die hard creationists... *please* don't tell me this is "what evolutionists believe" or something like that. This is factual, as-real-as-twinkies-are-tasty information I'm giving you, and by ignoring this you're only making the entire group of creationists look ignorant.
KathleenTheTerrible said:These differ with RNA and DNA sequences.
Indeed although they are largely the same. The main difference is that position 2 of the ribose molecule is lacking an oxygen atom in DNA whereas it is not in RNA (this leads to RNA being less stable due to acid hydrolysis). The other difference is that in terms of bases, RNA uses uracil instead of thymine.
KathleenTheTerrible said:The code is defined by the amino acids within the helix
This is where you go wrong. The code is what defines the amino acids. Amino acids are the building blocks of proteins. The nucleotide sequence (through DNA ---> pre-RNA ---> mRNA ---> tRNA ---> Amino acids) is what codes for the amino acid sequences which fold up into proteins.
KathleenTheTerrible said:These amino acids form our DNA, the very fabric that is our organic library and tell our body how to operate.
No. As explained above, DNA is not made up of amino acids. DNA is made up of (deoxy)nucleotides.
It should be noted that when people talk of DNA and nucleotide sequences they are really talking about deoxynucleotides, but it is commonly abbreviated as such. Strictly speaking nucleotides (not deoxy) are what make up RNA.
KathleenTheTerrible said:With each different genus, chromosome numbers vary.
Actually, it varies between species on the whole, not just genera.
KathleenTheTerrible said:A single flaw in one chromosome can cause major problems to a person. One chromosome! The damage of Chromosome 17 causes cystic fibrosis. That's how important it is to have all these little strands of DNA intact for these little cells.
I don't want to bog you down with too much detail, this is just for your interest really. The situation is actually even more amazing than that.
You're right that DNA is packed into chromosomes (although these only condense into the way we think of them during meiosis and mitosis). However, chromosomal rearrangements are pretty dramatic and at the large end of what normally causes genetic disease. There are 3 billion nucleotides in our genome which are packed onto 23 chromosomes (in us, obviously). Diseases tend to be on the nucleotide level rather than the chromosome level, merely because chromosomal damage tends to be lethal to any embryo. More than 50% of pregnancies auto-terminate, mainly due to chromosomal rearrangements. Down's syndrome is a classic example of non-lethal chromosomal disorders. However, sometimes (rarely) chromosomal rearrangements don't cause death, although the reasons for this are too complex for a brief summary here.
In fact, for some diseases the alteration of one nucleotide in the gene sequence can have drastic effects (see Sickle Cell Anaemia for example). The example you give of cystic fibrosis is not a chromosome-level disorder (and the responsible gene, CTFR, is on chromosome 7 not 17). In fact over 70% of CF cases are caused by three nucleotides being deleted from the gene, which results in the loss of phenylalanine (an amino acid) in position 508 of the CTFR gene product.
Hope this hasn't been information overload, and that it was interesting to you. I am a geneticist by trade, so it's sort of my passion too!
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