00:01
We have a strand of dna.
00:02
We want to know the sequence of the other strand.
00:06
So first of all, we need to know the base pairing rules.
00:09
These are chagaph's rules, after a guy who discovered them.
00:13
He noticed that cytosine always goes with guanine, and adenine always goes with thymine.
00:20
We'll make a note of urosil as well.
00:22
Thymein is found in the dna, uricil is found in the rna.
00:27
So we have a dna strand.
00:28
It has thymine.
00:29
We're looking for the other strand, so it's also going to have blinding, because we're still looking at dna.
00:36
So you can rule out answers d and e immediately, because they use eurasum.
00:41
Suppose aren't dna sequences.
00:44
The next thing we need to look at is the polarity.
00:47
So the strands we've been given goes 5 -prime to 3 -prime.
00:53
Now, nucleic acids always bind anti -parallel.
00:59
So our answer is going to go 3 -prime to 5 -prime...