I think one problem with our current system is that people can come here and post poor quality, off-topic, or homework questions etc. Normally these are closed fairly quickly, but often in the mean time an answer is posted (particularly annoying with homework questions I think). Ultimately this means the person who posted the question (OP) ends up getting an answer despite not conforming to the biology SE system. Examples:
In the first the question is clearly off topic and shows poor research effort, yet the poster still gets an answer. In the second the question is so poorly written and lacking essential information to make it useful to anyone, but the answer posted seems to (somehow - kudos Remi.b!) answer it. For the former I think there should be no answer given because it is off topic, and the OP will not learn to stick within the guidelines of bioSE. For the latter I think the OP will not provide the required edits because they have the answer they wanted, so there is no reason for them to clarify. Overall I think this prevents the improvement of questions and fails to discourage poor quality & off topic questions properly.
My suggestion is a new feature, the ability to hide answers (pre-emptively, before any answers are posted) for high rep users. A high rep user (>2000 points?) could see such questions and hide answers to the question for 24/48 hours... I imagine the following progression, with three possible outcomes:
A single close nomination from a high rep user will hide answers.
Answers can still be given but will only be visible to other high rep users, and the person that posted the answer, for the hiding period (perhaps 48 hours - most questions that close are closed within that sort of window, and it gives time for the OP to come back to it).
Unregistered and <2000 rep users will see a message along the lines of "This question has a hidden answer because the question is off-topic or fails to meet the guidelines of biology SE. Please edit the question to comply with biology SE guidelines."
If after 24/48 hours the question is closed the answer will remain hidden until it is reopened.
If the question is not closed the answer will become visible.
If the OP or another user edits the question to comply with bioSE guidelines before the 24 hour expiration, the post is referred to the review section, where a high rep user can reveal the answer if the edits deal with the problem.