00:02
Hello my dear students given in the question if you see there is a list of six scientists worked or contributed towards dna.
00:15
Now what is required for us is to match the name of the scientist with their discovery.
00:25
Okay, i'll put us as s here with their discovery what is mentioned in the drop down.
00:34
Okay so the correct discovery.
00:37
Is what we need to find out.
00:40
Let us get into the explanation.
00:43
The first scientist name which has been mentioned is linus pauling.
00:50
Linus pauling was one of the british scientist who was also called as father of molecular biology because he was the one who found out the twisted structure in proteins actually through x -ray crystallography technique.
01:34
Now what is his contribution in dna if you see the same technique he had put on dna also in one of his manuscripts on his studies he had mentioned that it is a triple helix compound.
01:52
So looking at his paper of published, it was proved wrong by james watson, scientist who gave the watson and crick model.
02:04
Yes, and it was proved wrong that according to linnaeus pauling, dna is not a triple helix model.
02:12
Okay, yes, so that is the corrupt option in the drop down.
02:18
The next scientist, if we see, is francis crick.
02:22
So francis crick again is a british scientist who along with james watson postulated and evidentially proved that dna is a double helic structure.
02:40
That's what their model or the postulation says is nothing but in double helix model of dna.
02:47
So in that one of the postulate which is correct with the scientist is they had proved that dna strands they are two in number and they run in opposite direction looking at the chemical composition of it.
03:04
So based on that only they had said that it is anti -parallel.
03:09
So the backbone, so the backbone of dna structure is made up of the sugars and the phosphate groups.
03:21
Now this run in opposite direction if it's one strand three prime to five prime, the other one is five prime to three prime.
03:28
So that is what they had proved that the two strands run anti -parallel to each other.
03:34
Yes, that was francis and crick's evidential work towards dna.
03:39
The other scientist what is given here is erwin shargaf.
03:45
Very easily we can find out what's his work because he was the one who postulated the rule in shargaaf's rule.
03:55
So he also worked towards the chemical composition of dna where he had told him...