Search found 3 matches

by YASHRAJ
Sun Aug 16, 2009 1:03 pm
Forum: Evolution
Topic: Why not hundreds of different sexes, why only two ?
Replies: 2
Views: 5350

Why not hundreds of different sexes, why only two ?

Sexual reproduction started with some reciprocal exchange of genetic material between similar individuals. But later organisms had to deal with the problem of inbreeding depression. As a result of this, a mechanism that ensures that sexual reproduction occurs only between unrelated cells, was evolve...
by YASHRAJ
Fri Jan 30, 2009 10:40 am
Forum: Molecular Biology
Topic: G-T Mismatch Repair
Replies: 4
Views: 4580

Re:

Yeah, 5-methyl cytosine gets spontaneously converted into thymine and in every case where it happens the G is correctly placed and T is wrong. But G-T mismatches can be formed due to some other reasons too ( e.g. replication errors) and there it is possible that the 'G' is incorrectly placed and 'T'...
by YASHRAJ
Thu Jan 29, 2009 7:08 am
Forum: Molecular Biology
Topic: G-T Mismatch Repair
Replies: 4
Views: 4580

G-T Mismatch Repair

Whenever a G -T mismatch is encountered in DNA, the cell repairs it using a specific mechanism which has a bias towards replacing T with C instead of replacing G with A. This helps in reducing mutations. But the question is - how does the cell know that it has to selctively replace T with C in a G -...