user61238: I saw an increase in the number of closed questions on the main page. From 46 questions I counted, 14 were closed. I understand biology overlaps with many fields so I checked "Computer Science" (14 questions on front page, 0 closed) and Mathematics (96 questions, 4 closed).
Many questions in Biology are marked as off-topic but are actually on topic. Here is a list composed of the off-topic I consider on topic (not all off-topic)
Why can't SCUBA tanks use pure oxygen, but deliver it to you through the regulator at a fifth the normal rate? - is a "general questions about biological concepts"
Do airsacs contract and expand when birds breathe? - is a question about a biological mechanisms
Difference between embryo and stem cells?  - is a "general questions about biological concepts"
sequence specific endoribonuclease - full disclosure, I asked it. is a "question about techniques in a biological or biochemical laboratory". It is marked as homework question. I got good possible answers in the comments.
Why doesn't oxygen give us 'the bends' like nitrogen does? -  - is a "general questions about biological concepts"
This question was marked as need clarity (not off-topic) but is very clear to me
Reviving an animal heart using electrodes
This posts do not have a comment recommending the author to change their question or explaining what is going on. This is NOT USER FRIENDLY, this does not allow the community to grow and is not positive criticism.
Many of these questions are general biology questions, not very sophisticated, but it is written that "Biology Stack Exchange is for people studying biology at any level".
I don't know how the process of closing a post works, I would like to know if this is the accepted policy of the Biology site, to close many questions and without explanation.

user9943: Welcome to Meta. I can address the questions here to motivate the mod-team's choices to close these questions. Importantly, you focus solely on the question whether the topic of the question suits this site yes or no, whereas the mod-team and other members of this community are at least as interested in the quality of the question at hand.

First and foremost, questions that are put on hold can always be edited and re-opened. Now on to the example questions you mention;
Reviving an animal heart using electrodes is a one-liner and importantly, it lacks any evidence of prior research and backgrounds (how long is the heart extracted from its host, what sort of electrodes, how much current, what voltage shape etc), but most importantly, why on earth would you want to do this in the first place? Adding background, motivation, and prior research help to focus questions and attract high quality answers.
Why can't SCUBA tanks use pure oxygen, but deliver it to you through the regulator at a fifth the normal rate? is arguably a better question than the former, but still lacks any prior research. There is no specific point made.
Do airsacs contract and expand when birds breathe? lacks any prior research.
Difference between embryo and stem cells? contains multiple questions, lacks focus and shows no signs of prior research either.
sequence specific endoribonuclease has been edited and re-opened in the meantime.
Why doesn't oxygen give us 'the bends' like nitrogen does?](Why doesn't oxygen give us 'the bends' like nitrogen does?) lacks details; especially when the astronauts experience the bends, as divers only suffer from it while resurfacing. I've placed a comment below the question.

I hope this helps to explain the closed questions.
I used the mod hammer in all these cases. Note that I, and other mods don't prefer to intermingle with community close-voting. However, oftentimes the close vote pile exceeds 50 posts and in general this community doesn't vote and review enough in my opinion. Reviewing and voting is important to keep this site up to standard. To support the small number of active members that do take up their tasks, I feel it my responsibility to now and then run through the review pile. If there are a lot of them to go through, I may now and then become a bit trigger happy. So thanks for this post. But again, after editing posts can always be re-opened and after editing they will automatically show up in the re-open review queue.
Indeed I ran through my close-vote queue recently and that's why the active question pages may show a spike in closed questions. A few days ago the queue exceeded 60 posts.
I always try to follow the community and almost never use the mod-hammer when the question has not received any other close votes and/or downvotes.

user27148: I think some of this might be confusion due to a change in how SE displays the reasons questions are closed. I think they made this change to simplify things and because they got feedback that the old wording was unfriendly; I don't agree but this isn't the place to rehash that. The area I am talking about looks like this:

You might only be seeing the first part of the banner: "Closed. This question is off-topic. It is not currently accepting answers". However, below this, the post author and users with sufficient rep will also see the specific reason.
These questions have been closed based on the "homework policy" at Biology.SE which requires askers to demonstrate their prior efforts. If you are able to see the full message (the OP always will), you can follow that link to this page: https://biology.stackexchange.com/help/homework It's not an issue of being "off topic" as in "not about biology", it's an issue of being "off topic" as in "not a properly scoped question for Biology.SE".
It's fine if a user comments to explain a close vote, but the information about the close reason is already there even without a comment.
I wish we had more site-specific tools to change how some of this wording displays. For the homework close reason I would prefer if we could display a different base message, but we cannot, and this is the only area that we can customize the close reasons (EDIT: actually I was wrong! it looks like we can do this; I had just remembered that Academia went through and improved all their custom notices recently). This issue has been raised before on the main meta, here: New Post Notices are live network-wide and maybe elsewhere.

In a comment, you ask "What is the benefit of closing a question?" There is a main Meta FAQ addressing this here: What is a "closed" or "duplicate" question?
In my mind, the most important thing about closed questions is that they cannot be answered in their current form. Closing questions that need attention from the OP before they fit site policies prevents people who don't know the policies from answering them, which encourages users not to improve their own posts.

61238: <p>I saw an increase in the number of closed questions on the main page. From 46 questions I counted, 14 were closed. I understand biology overlaps with many fields so I checked &quot;Computer Science&quot; (14 questions on front page, 0 closed) and Mathematics (96 questions, 4 closed).</p>
<p>Many questions in Biology are marked as off-topic but are actually on topic. Here is a list composed of the off-topic I consider on topic (not all off-topic)</p>
<p><a href="https://biology.stackexchange.com/questions/98021/why-cant-scuba-tanks-use-pure-oxygen-but-deliver-it-to-you-through-the-regulat">Why can't SCUBA tanks use pure oxygen, but deliver it to you through the regulator at a fifth the normal rate?</a> - is a &quot;general questions about biological concepts&quot;<br />
<a href="https://biology.stackexchange.com/questions/98028/do-airsacs-contract-and-expand-when-birds-breathe">Do airsacs contract and expand when birds breathe?</a> - is a question about a biological mechanisms<br />
<a href="https://biology.stackexchange.com/questions/98073/difference-between-embryo-and-stem-cells">Difference between embryo and stem cells?</a>  - is a &quot;general questions about biological concepts&quot;<br />
<a href="https://biology.stackexchange.com/questions/98081/sequence-specific-endoribonuclease">sequence specific endoribonuclease</a> - full disclosure, I asked it. is a &quot;question about techniques in a biological or biochemical laboratory&quot;. It is marked as homework question. I got good possible answers in the comments.<br />
<a href="https://biology.stackexchange.com/questions/98022/why-doesnt-oxygen-give-us-the-bends-like-nitrogen-does">Why doesn't oxygen give us 'the bends' like nitrogen does?</a> -  - is a &quot;general questions about biological concepts&quot;</p>
<p>This question was marked as need clarity (not off-topic) but is very clear to me
<a href="https://biology.stackexchange.com/questions/98056/reviving-an-animal-heart-using-electrodes">Reviving an animal heart using electrodes</a></p>
<p>This posts do not have a comment recommending the author to change their question or explaining what is going on. This is NOT USER FRIENDLY, this does not allow the community to grow and is not positive criticism.</p>
<p>Many of these questions are general biology questions, not very sophisticated, but it is written that &quot;Biology Stack Exchange is for people studying biology at any level&quot;.</p>
<p>I don't know how the process of closing a post works, I would like to know if this is the accepted policy of the Biology site, to close many questions and without explanation.</p>
 9943: <p>Welcome to Meta. I can address the questions here to motivate the mod-team's choices to close these questions. Importantly, you focus solely on the question whether the topic of the question suits this site yes or no, whereas the mod-team and other members of this community are at least as interested in the <em><strong>quality</strong></em> of the question at hand.</p>
<ol>
<li>First and foremost, questions that are put on hold can always be edited and re-opened. Now on to the example questions you mention;</li>
<li><a href="https://biology.stackexchange.com/questions/98056/reviving-an-animal-heart-using-electrodes">Reviving an animal heart using electrodes</a> is a one-liner and importantly, it lacks any evidence of prior research and backgrounds (how long is the heart extracted from its host, what sort of electrodes, how much current, what voltage shape <em>etc</em>), but most importantly, why on earth would you want to do this in the first place? Adding background, motivation, and prior research help to focus questions and attract high quality answers.</li>
<li><a href="https://biology.stackexchange.com/questions/98021/why-cant-scuba-tanks-use-pure-oxygen-but-deliver-it-to-you-through-the-regulat">Why can't SCUBA tanks use pure oxygen, but deliver it to you through the regulator at a fifth the normal rate?</a> is arguably a better question than the former, but still lacks any prior research. There is no specific point made.</li>
<li><a href="https://biology.stackexchange.com/questions/98028/do-airsacs-contract-and-expand-when-birds-breathe">Do airsacs contract and expand when birds breathe?</a> lacks any prior research.</li>
<li><a href="https://biology.stackexchange.com/questions/98073/difference-between-embryo-and-stem-cells">Difference between embryo and stem cells?</a> contains multiple questions, lacks focus and shows no signs of prior research either.</li>
<li><a href="https://biology.stackexchange.com/questions/98081/sequence-specific-endoribonuclease">sequence specific endoribonuclease</a> has been edited and re-opened in the meantime.</li>
<li><a href="https://biology.stackexchange.com/questions/98022/why-doesnt-oxygen-give-us-the-bends-like-nitrogen-does">Why doesn't oxygen give us 'the bends' like nitrogen does?</a>](<a href="https://biology.stackexchange.com/questions/98022/why-doesnt-oxygen-give-us-the-bends-like-nitrogen-does">Why doesn&#39;t oxygen give us &#39;the bends&#39; like nitrogen does?</a>) lacks details; especially <em>when</em> the astronauts experience the bends, as divers only suffer from it while resurfacing. I've placed a comment below the question.</li>
</ol>
<p>I hope this helps to explain the closed questions.</p>
<p>I used the mod hammer in all these cases. Note that I, and other mods don't prefer to intermingle with community close-voting. However, oftentimes the close vote pile exceeds 50 posts and in general <a href="https://biology.meta.stackexchange.com/a/3801/9943"><strong>this community doesn't vote and review enough</strong></a> in my opinion. Reviewing and voting is important to keep this site up to standard. To support the small number of active members that do take up their tasks, I feel it my responsibility to now and then run through the review pile. If there are a lot of them to go through, I may now and then become a bit trigger happy. So thanks for this post. But again, after editing posts can always be re-opened and after editing they will automatically show up in the re-open review queue.</p>
<p>Indeed I ran through my close-vote queue recently and that's why the active question pages may show a spike in closed questions. A few days ago the queue exceeded 60 posts.</p>
<p>I always try to follow the community and almost never use the mod-hammer when the question has not received any other close votes and/or downvotes.</p>
 27148: <p>I think some of this might be confusion due to a change in how SE displays the reasons questions are closed. I think they made this change to simplify things and because they got feedback that the old wording was unfriendly; I don't agree but this isn't the place to rehash that. The area I am talking about looks like this:</p>
<p><a href="https://i.stack.imgur.com/meqWx.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/meqWx.png" alt="enter image description here" /></a></p>
<p>You might only be seeing the first part of the banner: &quot;Closed. This question is off-topic. It is not currently accepting answers&quot;. However, below this, the post author and users with sufficient rep will also see the specific reason.</p>
<p>These questions have been closed based on the &quot;homework policy&quot; at Biology.SE which requires askers to demonstrate their prior efforts. If you are able to see the full message (the OP always will), you can follow that link to this page: <a href="https://biology.stackexchange.com/help/homework">https://biology.stackexchange.com/help/homework</a> It's not an issue of being &quot;off topic&quot; as in &quot;not about biology&quot;, it's an issue of being &quot;off topic&quot; as in &quot;not a properly scoped question for Biology.SE&quot;.</p>
<p>It's fine if a user comments to explain a close vote, but the information about the close reason is already there even without a comment.</p>
<p>I wish we had more site-specific tools to change how some of this wording displays. For the homework close reason I would prefer if we could display a different base message<s>, but we cannot, and this is the only area that we can customize the close reasons</s> (<strong>EDIT</strong>: actually I was wrong! it looks like we <em>can</em> do this; I had just remembered that <a href="https://academia.meta.stackexchange.com/questions/4710/new-audience-specific-texts-for-our-custom-close-reasons">Academia went through and improved all their custom notices recently</a>). This issue has been raised before on the main meta, here: <a href="https://meta.stackexchange.com/questions/339700/new-post-notices-are-live-network-wide/339733#339733">New Post Notices are live network-wide</a> and maybe elsewhere.</p>
<hr />
<p>In a comment, you ask &quot;What is the benefit of closing a question?&quot; There is a main Meta FAQ addressing this here: <a href="https://meta.stackexchange.com/questions/10582/what-is-a-closed-or-duplicate-question">What is a &quot;closed&quot; or &quot;duplicate&quot; question?</a></p>
<p>In my mind, the most important thing about closed questions is that <em>they cannot be answered in their current form</em>. Closing questions that need attention from the OP before they fit site policies prevents people who don't know the policies from answering them, which encourages users not to improve their own posts.</p>
