view the rest of the comments
Ask Lemmy
A Fediverse community for open-ended, thought provoking questions
Please don't post about current US Politics. If you need to do this, try !politicaldiscussion@lemmy.world or !askusa@discuss.online
Rules: (interactive)
1) Be nice and; have fun
Doxxing, trolling, sealioning, racism, and toxicity are not welcomed in AskLemmy. Remember what your mother said: if you can't say something nice, don't say anything at all. In addition, the site-wide Lemmy.world terms of service also apply here. Please familiarize yourself with them
2) All posts must end with a '?'
This is sort of like Jeopardy. Please phrase all post titles in the form of a proper question ending with ?
3) No spam
Please do not flood the community with nonsense. Actual suspected spammers will be banned on site. No astroturfing.
4) NSFW is okay, within reason
Just remember to tag posts with either a content warning or a [NSFW] tag. Overtly sexual posts are not allowed, please direct them to either !asklemmyafterdark@lemmy.world or !asklemmynsfw@lemmynsfw.com.
NSFW comments should be restricted to posts tagged [NSFW].
5) This is not a support community.
It is not a place for 'how do I?', type questions.
If you have any questions regarding the site itself or would like to report a community, please direct them to Lemmy.world Support or email info@lemmy.world. For other questions check our partnered communities list, or use the search function.
Reminder: The terms of service apply here too.
Partnered Communities:
Logo design credit goes to: tubbadu
Or put biologically, virtually all fauna are just various advanced forms of flatworm.
IIRC humans have 7 holes topologically (assuming both vsauce and my memory are correct). I'm not sure how many a flatworm would have, but I bet you could group animals by number of holes topologically, which might be interesting.
Flatworms have a single opening that leads to a branching cavity (an incomplete digestive system). This means that the single opening is for both ingesting nutrients and expelling waste. While your mouth may be attached to your anus via the alimentary canal, I think it beats the hell out of having one multi-purpose opening, imho.
Right, technically a human only has 1 hole for ingesting nutrients and expelling waste as well though, assuming you are talking about the mouth and anus. Does a flatworm have any other through holes though e.g. nostrils or tear ducts? I have no idea what the biology of a flatworm is haha.
No, gas exchange is by simple diffusion across the skin and gut. No ears or eyes per se, just some photosensitive cells in slight depressions on the head. Planaria are pretty simple as far as animals go.
Two ears, mouth/anus/nostrils, urethra, optionally vagina. That's 5...what else, eye sockets?