00:01
Hi everyone, in this question we have been said to construct a chromosomal map from the following chart showing the crossover frequencies for linkage group on autosome.
00:14
So basically here the gene map on the chromosome will be like this.
00:21
So here the c is present, here the a is present, here the b is present and here the s is present.
00:31
So according to the data given to us here, ab has 2 .5 frequencies.
00:37
So that means here it will be 2 .5 distance, then between b, c, a it is 3.
00:45
So here it will be 3, then b, c it is 5 .5.
00:52
So here we will write 5 .5, then between b and s, here it is 5 .5.
01:02
Then between a and s, it is 8 .0, then between c and s, it is 11 .0.
01:11
So this here is the map.
01:14
The recombination frequency reveals the distance between the genes and the genes are arranged in linear fashion on the dna molecule.
01:21
So the genes that are farthest are the c and s.
01:26
So that is why their recombination frequency or the crossing over is highest.
01:30
The genes a and b are closest.
01:33
So that is why the crossing over that will take place between a and b is the rarest.
01:37
Then the next one here, we will write a, c, d, f and b.
01:47
So now the distance between a and b is 24 centimorgan.
01:56
Now between a and c, it is 8 .0.
02:02
Then between c and d, these are closest here with 2 .0.
02:07
Then between a and f, so it is 16 .0.
02:13
Then between f and d, it is 8.
02:16
Between d and f, it is 6 .0.
02:19
So here we can see that the farthest in this are a and b gene.
02:24
That is the reason why their crossing over percentage is high because they are the farthest and the genes separate more by crossing over and the distance between c and d is very minimum...