Quote:
Originally Posted by kayleigh.
it was the sections which included humans in which i was most interested in. as i wanted to know how and why everything in a human works, but what starts it all off? is the mother/baby relationship basically like jumpstarting a car?
|
Hello kayleigh, I would say that with humans it begins with sex
and that a new individual forming is more like an avalanche than jumpstarting a car. Once an egg and sperm cell...both individual, free-living cells...unite to form a single cell (kind of like the reverse of eating!), the cell divides to form two cells, and each of those divide, and so on and so on....like a tumor, but with organized structures. I view there as being no "beginning" of a human because the egg and sperm that united to become what would grow into me were also "me" in the sense that they were alive and I continue their life. Many embryos (perhaps 1/3rd, I recall reading) have defects causing them to die before a person even realizes she is pregnant. When you ask about how a human works, do you mean you are interested in how all the embryonic cells divide and move around to create the different parts of a baby human?
Quote:
Originally Posted by dollarsandcents
Just to nitpick, A (adenine) is complementary to T (thymine) and G (guanine) is complementary to C (cytosine). Triplets of these also code for amino acids, which in turn generate chains of protein with specific structures related to their function. Just to elaborate.
|
Oh, good catch, dollarsandcents! I just sort of bleeped right over whether the fake DNA sequence correctly used complementary nucleotides on annealing strands!
10-14-2009, 02:50 PM
Threaded Mode