Edited to fix misremembered definitions of mitosis and meiosis.
bkelly writes:
That depends on how we define reconstruct. Lets see if I have this right.
If I understand you correctly, I'm pretty sure you have this wrong. It looks like you're confusing the two halves of a chromosome pair with the two halves of the DNA double helix. You've got the formation of gametes (haploid sexual reproductive cells or meiosis) mixed up with mitosis (cell division). It looks this way to me because you go on to say:
The chromosomes split into two pieces. From each of these two pieces (really each piece seems to be multiple pieces, but the term piece refering to each complete half of the DNA should suffice) the entire and correct dna sequence can be constructed.
Sperm and egg are haploid cells, meaning they only have half the full chromosome complement. For humans, instead of having 23 chromosome pairs like all other cells, sperm and egg have only 23 individual chromosomes. A haploid cell is created during meiosis by selecting only one chromosome from each pair.
Every chromosome is a lengthy and tightly coiled strand of DNA. During mitosis every chromosome (all 46 in humans) has it's DNA split down the middle, and each half goes to one of the two cells created by the division. These DNA halves are used as templates to rebuild copies of the original DNA strands. These rebuilt strands form the chromosomes (again, 46 in humans) which then gather back together into the chromosome pairs (23 in humans).
--Percy
This message has been edited by Percy, 11-18-2005 12:43 PM