00:01
Hello, we're looking at biology 2015, chapter 12, problem 3.
00:06
If 30 % of an organism's dna is thymine, then we have five choices.
00:12
A, 70 % is purine, b, 20 % is guanine, c, 30 % is adenine, d, 70 % is primidine.
00:21
Both a and c are correct.
00:23
When we're attacking a question like this, there's a couple of things that we need to know.
00:27
For one, we should look at each option.
00:31
A, b, c, and d.
00:32
Don't just stop at the first correct answer, especially when they throw in a both b and c are correct or something similar or all of the above is correct.
00:40
We need to check out all of the answers.
00:43
This particular question is shargaff.
00:50
Whoops, that's not typing.
00:54
An application of shargaff's rule.
00:57
And what shargraph said was, cairines are in a one -to -one relationship with primidines.
01:09
So right off the bat, if we have 100 % of bases and we have a one -to -one relationship, that means purines and primidines are each 50 % of the choices.
01:25
So right away, we can cross off a and we can cross off d...