4 in the scenario above how might you define the gene y...

Transcript

00:01 Hello students in the question it is said that ura 3 gene is responsible for the synthesis of uracal base in r &a and a geneticist has a ura 3 in our laboratory whose sequence is 5 prime aatt and g t t t t g g g .a.

00:41 This geneticist caught a yeast strain which was oxotrophic for uracel.

00:50 That means in the presence of uracel that yeast grows, which means that yeast was unable to make uracel.

00:58 Why? because there was a mutation in ura3 gene.

01:08 So this geneticist sequenced the three alleles of ura3 mutant gene and had the sequences respectively as this.

01:31 These are the sequences of three alleles of a mutant gene.

01:37 One is given in 5 from 3 prime direction and the other two are given in 3 prime and 5 prime direction.

01:44 So we have to compare these with the non -mutant or the gene without mutation so that we can find where the mutation has occurred.

01:57 But before doing that, we have to change this 3 prime 5 -prime direction to 5 -3 -prime direction.

02:06 Like, so these will be the 5 -3 -prime direction sequence of these two alleleys.

02:14 Now let's compare these three alleles with the original gene here.

02:22 So i put the sequences one above another this is the original one and these are the mutant ones i put them one above another so that we can get the idea where the mutation is.

02:39 If we look at them the mutation is here instead of g there is c this one is the same as the original and this one here is the same as the mutated one.

02:55 So the mutation here is t is replaced with c, thymine is replaced with cytosine here.

03:09 Now since there is a mutation in the ura3 gene the geneticist wants to revert this mutation and to do so she has certain mutagenal in hand or the methods by which she can revert the mutations and we have to tell which one applies to the fact that we get the correct mutation or we get the revertent back from the mutant one where c is replaced with t again so to revert back the mutation she has four choices which are she has a mutagen's hydroxylamine which modifies c and this c then peers with a.

04:09 Number second, she has an x -ray...

Question

4. In the scenario above, how might you define the Gene Y mutation? A. transition mutant B. transversion mutant C. indel mutant D. true revertant E. suppressor mutant

Question

4. In the scenario above, how might you define the Gene Y mutation? A. transition mutant B. transversion mutant C. indel mutant D. true revertant E. suppressor mutant

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