I got minor revision in the first round of review. The main concern of the reviewer was to add the details in methods section and some amendments in the text. I re-submitted the paper after incorporating these changes in the manuscript (I work in Biology field). But the status of the paper is showing "under review" again. Does it mean the manuscript will go through peer review again? what are the chances of the paper being accepted? Please help..
Whether or not the manuscript is going through peer review again depends on the editorial manager system the journal is using. If the status goes something like "submitted to journal" -> "editor assigned" -> "under review", then yes, it means your paper is going through peer review again. If it goes "submitted to journal" -> "under review" (i.e. it doesn't tell you that an editor has been assigned), then there's no way to tell until you receive a decision. A quick decision implies it didn't go through peer review again; a slow one and / or reviewer comments indicates it did.
There's no way to be sure if the the paper is likely to be accepted without knowing more about the paper's content & the review. However, based on your description, chances are good it'll be accepted eventually. If the corrections are minor and you've performed them, there's no reason for rejection.