here by i have an doubt in ligation. what happens when ligating undigested plasmid. If it ligated means what are the possibilities? can anybody say about it?
Basically when you ligate undigested plasmid, and then use it to transform compentent cells, all you are doing is cloning undigested plasmid.
In short, you get a lots of "clones" from your ligation, but none of them have the desired insert because the undigested plasmid will not accept the insert, since it is undigested and thus not open to accept inserts, while at the same time it will transform competent cells with high efficiency since it is circular/undigested.