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Identification of a small flat bug
So for the last few days I have been noticing these small bugs in my bathroom -- they don't appear frequently, and I see them once or twice a month.
The characteristics and behavior I observed are as follows :

They RARELY move around.
They are extremely flat, like totally flat
Some are small, some are big (but still the overall size is small)

Below are the pictures :

I cropped this picture since the original size was 5mbs and the limit was only 2. If anyone wants the original image I can inbox them .
Appreciate any help or suggestion with this :)
EDIT 2
I am adding another image for greater clarity , hope this helps

Edit 3
Location: Karachi Pakistan.
Size: 0.2-0.4 cm
As for nearby animal populations: No not much, just the usual street cats.
For a few months these bugs were gone until recently they have started to appear in the bathroom, like I see them 2-3x a month just sitting still for hours and hours.

The image is just blurry enough that I can't tell if it has 6 legs or 8. It almost reminds me of a tick. But ticks don't normally infest bathrooms.

It has 8 legs , I can upload another good quality image but the size limit 2mbs , the original image is around 7mbs in size.
Yes thats what I originally thought that it was a tick but they are always seen in the bathrooms just staying at the wall for hours and hours without movng

Do you have a pigeon problem? Do you live near a cave or visit caves? Do you interact with poultry birds?

It seems my comment was removed , anyway i'll again comment:
My location is Karachi Pakistan , its around 0.2 to 0.4 cm in length and mostly the typical street cats around BUT now that you have mentioned it yes there are pigeons around my window , they sleep at a small hedge just above my window sometimes and at the bathroom window too

Related: https://biology.stackexchange.com/q/31383/16866

Definitely an arachnid and mite (subclass Acari), and very likely a member of the order Parasitiformes, of which there are more than 100,000 species!!
Your specimen brings to mind the family Argasidae (the "soft ticks" -- so called because they lack a hard scutum).
Specifically, your specimen reminds me of Argas reflexus, the pigeon tick. (which has been found to be an increasing pest and human concern in urban settings).

 Credit: Milan Kudlička
Based on the size of your specimen, I would guess you're looking at a non-adult stage.
However, this is just a guess, and I will try to explore other species in this general group to see if I can come up with a better-supported guess.
(By the way: any pigeons living nearby??)

I think you are correct with this , its not exactly like this what you posted but its very very much like them . Yup there are pigeons and maybe those are pigeon ticks like what you mentioned

Well there you go! The presence of pigeons outside your window makes sense. Please upvote accept the answer if you find it acceptable. Thanks! :)

Sure , thank you for this , just one last question are they dangerous ? Like do I need to be concerned about them ? and any tips on how to remove them ?

Thanks for accepting my answer -- please upvote, too, if you think it's deserving. As for dangerous: see the link in my answer's 3rd paragraph (you'll likely have to translate from Italian). There's evidence that repeated bites can increase your odds of developing anaphylactic shock and possibly being exposed to harmful pathogens (though no clear example of human pathogens seems to exist in this species from what I've seen). For removal: the pigeons will have to go or the ticks will keep showing up. However, any ticks remaining after removing pigeons will still be looking for blood...

I voted but since I am new the vote is not showing as I need toto have a repo greater than 15 , but I have voted :) and thank you for the suggestions :)


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What is this rather large insect in northwestern USA?
As you can see from the ants in the first picture, this insect is peculiarly large - over an inch long. I thought it was dead in the first picture, but it started moving around the next day. A couple of days later I found it again, dead. I have two dead specimens and other pictures if desired.

I think I've seen a shedded exoskeleton of one on a forest trail and another dead one from months earlier.
What species is it?
Location: Oregon, USA.

source: Stack Exchange

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sort: votes


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How do we determine what we call "flexion" and what we call "extension"?
Question:
How did we determine which motion to call "flexion" and which to call "extension" with regard to the wrist and the neck?
Background:
Just to set the stage, I'm not asking for help on homework here. I'm a veterinarian and I teach human anatomy. Terms for joint movements make sense to me on a surface level, but the more I think about them, the more confused I get.
I have read some good comments and sources on biology stackExchange, such as this discussion.
But the more I think about it, the less it all makes sense.
My initial question was "why do we use dorsiflexion and plantar flexion" instead of simply saying "flexion" and "extension?" My confusion is not about plantar/dorsal-- coming from the veterinary side, that part is easy for me. Rather, my confusion is about why we don't simply refer to dorsiflexion as "flexion" and plantar flexion as "extension."
Someone mentioned in the link above that anatomists wanted to emphasize the connection between ankle and wrist in their terms. That made some sense... except that we end up using different terms in the ankle vs the wrist. And in any case when I think about this, I start to wonder-- how do we define flexion or extension of the wrist in the first place? I mean to some degree it's intuitive, thanks to everyday language use. I don't know exactly how that intuition arises-- perhaps by analogy to the elbow and knee, I generally think of "flexion" as being the more active movement for picking something up or moving something, while extension is usually for putting things back down, and flexion tends to make the bigger muscles bulk up. But if we want to be objective about it, how would we do that?
Either movement of the wrist reduces the angle between the hand and the arm. Either movement requires some muscles to relax and their counterparts to contract. Either movement can accomplish important physical functions.
I can understand how we arrive at objective terms for the knee and elbow. If we start in the anatomical position, we cannot significantly reduce the angle between the distal and proximal parts except by moving in one direction-- which we can call flexion. Extension is the opposite, and in the unfortunate event that some external force moves us beyond the normal range, we get hyperextension. So far so good.
But this doesn't apply to the wrist, or for that matter the head, so we're back to the drawing board. Starting from the anatomical position, any movement of the head or hand reduces the angle from 180 degrees to something less than that. (The foot is in fact the only one of these three where it makes much sense to simply use extension and flexion; since we start at 90 degrees from the shin, dorsiflexion reduces the angle, and so could to my mind be called flexion, while plantar flexion increase the angle up to 180 degrees, and so in my mind could simply be called extension. And yet for the foot, we don't use these terms!)
Others have mentioned it has to do with the coronal plane-- reducing the angle between the body part and the coronal plane is flexion. But this doesn't really hold up either; both flexing and extending the head increase the angle between the head and the coronal plane. Same with the wrist. This just doesn't seem universally applicable period.
When it comes to why we use plantar flexion and dorsiflexion of the foot instead of flexion and extension, I can appreciate that the foot is uniquely positioned at a 90-degree angle from the long axis of the body, so that the joint is not, in anatomical position, oriented along the coronal plane, while most other limb joints and the head are. So I am open to this being an explanation for why the standard terms don't apply, but to understand that, I need to understand how and why the other terms do apply more generally.
I am willing to accept it if the best possible answer is "we arrived at these terms through a history of common usage and there is no explanation other than the subjective opinions of early anatomists." But I'd love to know if there is something better.
To summarize my main question is:  how did we determine which motion to call "flexion" and which to call "extension" with regard to the wrist and the neck?

Hi and welcome! On this site, people asking (and answering) questions are expected to provide some evidence of their research into an answer. (Yes, some impulsive people answer questions without such evidence, but it's still expected.) From a biologist/scientist, it's even more reasonable to expect some background research. Did you look for historical references? Or the etymology of flexion/extension? I'm sorry if this sounds silly (especially in the light of my having done it, too) but can you include your research? Thanks!

My guess is simply our anteriorly-oriented world view since both flex anteriorly in anatomical position. Although directionality (anterior vs posterior) aren't necessary to define either flexion/extension (see the post you linked for more detail), I could see the confusion surrounding the otherwise arbitrary choice of using these terms in the fashion chosen vs the opposite convention. I think a solid answer here has to pull out one of the classic Greek texts (or whomever 1st utilized these terms in this fashion) to shed adequate light on this.

You might find more helpful resources by searching for atlanto-occipital and radio-carpal joints more precisely

@theforestecologist - I'm curious why you say Greek. My poking around puts flexion (from flectere, to bend) first used to describe, well, joint flexion, in v. early 1600's. Most scholars in the West used Latin back then, no? I can't seem to get further back to Greek.

@anongoodnurse I just guessed some older language without putting much thought into it (hence my parenthetical). You did the right thing by looking at the etymology (I didn't take the time yesterday to look since I made these comments quickly between tasks). Thanks for following up about it!

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Bug Identification: Tiny Bugs in Fairport NY

We have been finding a ton of these tiny bugs (pin head size or smaller) outside on our patios, outdoor tables, on the grill, etc.
What are they and how do we get rid of them?

Related posts: Can Anyone Identify This Insect?, What are these tiny, swarming, jumping bugs?, Help identifying tiny jumping bug, Taxonomy: Categorising Collembola, What kind of small insect is this?, Unknown aquatic larvae

These bugs are a type of hexapod called springtails (subclass Collembola). Springtails are often very tiny and hard to see without a lens, so I have to say you did a good job grabbing a fairly detailed picture of this one. Specifically, your specimen appears to be some species in the order Entomobryomorpha.
According to Wikipedia:

They can be best distinguished from the other springtail groups by their body shape...The Entomobryomorpha...contain the slimmest springtails [with]...long bodies. [They also have] well-developed furculae

Specific species:
Usually, IDing springtails is very difficult, but I believe your specimen matches a fairly widespread species called Entomobrya nivalis (aptly named the cosmopolitan springtail).

 Source: Wikipedia; photo credit: James Keith Lindsey
The description of this species matches yours fairly well. From Wikipedia:

The cosmopolitan springtail measures about 2 mm in length. Its color consists of a yellow or white background with dark pigment forming transversal bands along the third segment of the thorax and the segments 2 to 6 of the abdomen. The fourth segment of the abdomen has a U- or 11-shaped pattern that easily distinguishes this species from others in the genus Entomobrya+

Somewhat true to its name, this somewhat cosmopolitan species is found in temperate and polar regions across North America and Europe+. Adults typically live among lichens and trees (whereas young live in leaf litter), however, according to NC State Extension:

Rarely springtails may become exceedingly abundant and may congregate in heaps several inches high on driveways, sidewalks and poolsides.

So what exactly is a springtail??
In general, springtails usually feed on decaying matter, and -- you guessed it -- they're known for their ability to jump!

Springtails are so-called because they have a unique structure, the furcula, that allows them to jump for considerable distance relative to their tiny size. [source].

 Springing mechanism of a generalized springtail. Credit: Marianne Alleyne [Source]

+ Wikipedia cites Katz, A.D.; Giordano, R.; Soto-Adames, F. (2015). "Taxonomic review and phylogenetic analysis of fifteen North American Entomobrya (Collembola, Entomobryidae), including four new species". ZooKeys. 525. doi:10.3897/zookeys.525.6020

Those are Collembola, something in the line of this genus https://bugguide.net/node/view/91878. They are harmless to humans, usually live in the leaf litter and I don't know if there's really anything you can do to control them. Let's see if any expert in Collembola chimes in.

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Species identification. Is this a leech?

The pictured creature, shown at the bottom of a glass, was attached to a friend’s child after he was swimming in the Ottawa River today. It stretches out to roughly an inch in length but in this “resting pose” was around half that length. Below is a shot of the mark left behind:

It looks like a leech to me, but I thought I’d ask the Internet.

Welcome to Bio.SE! What attempts to answer this question have you already taken? We ask that all question posters here attempt to search for an answer to their own question and explicitly indicate what research they've already done, what they learned, and what is still confusing or unknown to them. Our goal is not to simply be an answer site, but rather a site that promotes self-learning with some expert help along the way :). Please take a moment to edit your post with this additional detail, and it will likely be received more positively by our community. Thanks!

Thanks, I'll try to do better next time.

Yes this is a leech. It appears to be a species in the family Glossiphoniidae, or the freshwater jawless leeches. This family of leeches is relatively flattened with a poorly defined anterior sucker.
According to The Canadian Encyclopedia, there are about 45 species of leeches found in or around Canada.
Langer et al. (2018)1 provide a more limited selection of Glossiphoniidae leeches they ascribed to Ontario. Of the ones they list, yours most looks like a specimen from the genus Placobdella.
See, for example, this image of Placobdella phalera from de Carle et al. (2017)2 found in Ontario, Canada:

 Source: Figure 1, de Carle et al. (2017)

1  Langer, S.V., Vezsenyi, K.A., De Carle, D., Beresford, D.V. and Kvist, S., 2017. Leeches (Annelida: Hirudinea) from the far north of Ontario: distribution, diversity, and diagnostics. Canadian Journal of Zoology, 96(2), pp.141-152.
2  de Carle, D., Oceguera-Figueroa, A., Tessler, M., Siddall, M.E. and Kvist, S., 2017. Phylogenetic analysis of Placobdella (Hirudinea: Rhynchobdellida: Glossiphoniidae) with consideration of COI variation. Molecular phylogenetics and evolution, 114, pp.234-248.


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What is the identity of this flower found in Mavericks Beach in Half Moon Bay, California, USA?
Please help identify this flower I saw in Mavericks Beach in Half Moon Bay, California. It was smelling soooo good, you can feel from distance. I want to buy and plant in my garden.
Thank you,

Based on the habitat, color, and size that lupine looks like Coastal bush lupine (Lupinus arboreus).
Please note that Coastal bush lupine can be invasive, so be responsible about where you plant it!
You can also learn more about this plant and its growth requirements from the California Native Plant Society
Images for comparison:


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What kind of skull is this-I found it on the beach in Cape May
I am hoping someone can help identify this skull! We found it on the beach in Cape May. The skull size is about 4 inch in length. Thank you.

www.boneid.net provides a great searchable database of identified bones

Eyes at sides, have incisors and molars. This is a herbivore and not a sea mammal. According to the large incisors and placement of the teeth, I think it's a rodent.

Harun, Do you know what kind of rodent it might be?

Possibly a gopher.


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What is this insect (Germany)?

It was hovering and in between it was very fast and hard to photograph. I'm not even sure if it is an insect? Photographed in Germany.

It's hard to tell from your photo, but you should check whether Macroglossum stellatarum (German: Taubenschwänzchen/ English: hummingbird hawk-moth) looks similar to what you've seen.
This moth is living in Germany (and other regions) and due to it's way of flying (hovering and audible humming) it's sometimes confused with a hummingbird.

Seems to be right. I tried hard to make a good photo but it was too fast and I never got it into the seeker fast enough...

@mike I've seen it once and fully understand that it's hard to take a proper picture :)


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At what stage is the nervous system developed enough to interpret neuronal signals as 'pain'?
According to this article in Live Science, one of the reasons the fetus can't feel pain until 19 weeks is because the nervous system isn't fully developed.
But according to this article, the heart starts beating at day 16.
And according to this article, the nervous system controls the rate beating of the heart.
Then my question is, **how can it be assured that the nervous system isn't developed until 19 weeks, when the nervous system controls the heart beating rate since day 16?

First, there is some confusion on your part about heart cells and pain perception. Heart cells generate an action potential intrinsically; they do not need the central nervous system to beat (your second article explains this; read the part about the importance of calcium.) So yes, long before a fetus can feel pain, the heart is beating, because there must be circulation of nutrients throughout the embryo.
Secondly, the vagus nerve and sympathetic nerves can affect heart rate (the former by slowing it down when firing). These nerves start to reach their endpoints late in week 4 of development. So 19 days is not correct.

Cardiac sympathetic system
Although the primitive human heart starts to beat at 21 to 22 d, heart development continues to day 50, and it is near the end of this period, during the fifth week, that thoracic neural crest cells migrate from the neural tube through the somites and form aggregations (ganglia) near the dorsal aorta. [emphasis mine]

To experience pain, however, requires maturation of certain parts of the brain, most importantly, part of the thalamus and the cerebral cortex:

Current theories of pain consider an intact cortical system to be both necessary and sufficient for pain experience. In support are functional imaging studies showing that activation within a network of cortical regions correlate with reported pain experience. Furthermore, cortical activation can generate the experience of pain even in the absence of actual noxious stimulation. These observations suggest thalamic projections into the cortical plate are the minimal necessary anatomy for pain experience. These projections are complete at 23 weeks' gestation.  [emphasis mine]

Fetal surgeons and anesthesiologists often use 20 weeks as the time at which a fetus can start to feel pain, because that is when the fetus reacts to stimuli that would be recognized as pain if applied to adults (e.g. recoiling from noxious stimuli.)
One must recognize that recoiling from noxious stimuli does not prove what the fetus is perceiving. But it's a step in the direction of protecting the fetus from unnecessary pain.
Autonomic cardiac innervation: Development and adult plasticity
Can fetuses feel pain?

Thanks, this is basically exactly the answer I would have wanted to give but felt I didn't have the time at the moment to track down some sources and nail down the timing of different developmental events.

This answer is very good, but it has risen many other questions. I dont know if post them here as comments or post them as new questions. The third article does state the nervous system controls the heart rate, doesnt it? " Your heart rate, both at rest and during exercise, is controlled by the nervous system "

@Pablo - if they are new questions, post them as new questions. :)

@anongoodnurse ok, I just will in a while

@Pablo It's probably better to say the nervous system modulates the heart rate, once the nervous system has developed connections with the heart. If you provide it with the correct nutrients and ions, the heart can keep beating for awhile even completely outside the body. In a developing fetus, the heart can certainly beat on its own without nervous input. The nervous input becomes important when your metabolic needs are changing at a moment to moment basis, like when you exercise: that doesn't really apply to a developing fetus.

I found one of the answers here https://biology.stackexchange.com/questions/35180/will-the-heart-keep-beating-if-its-separated-from-the-body "The brain regulates the rate of the heart beat sure, but it does not send the signals that cause the heart to beat in itself."

This answer might need to be updated. Aside of several sources stating things like "However, a mature cerebral cortex is not necessary in order for the unborn child to feel pain, as evidenced by scientific studies and observations that both children and adults who are born with no or minimal cerebral cortex, do in fact still perceive pain." https://downloads.frc.org/EF/EF15A104.pdf there are others sources which state hearing or purpose movement start before 20 weeks. If hearing and consciouness is present before 20 weeks is hard to believe pain isnt since the experiences are connected.

@Pablo - I personally believe that fetuses feel pain before 20 weeks, but I will not change the answer to help you confirm your opinions/biases. It's a good answer. Feel free to answer yourself, altough I noted you above that you misinterpreted what the 'science' is.

Development isn't my area of expertise within neuroscience, but without evaluating each of your sources (note: it might be better to read actual scientific articles; live science and especially livestrong are basically blogs; I haven't heard of iflscience but assume it is similar), it is important to recognize that the "nervous system" isn't all one unit, it is a collection of many networks and circuits.
There is no universal "on" switch where one day it is off and the next it is suddenly all working. Different pieces develop at different paces, and many functions are still developing even long after birth, through adolescence. In general, you can assume that the most basic functions necessary to sustain the body will develop first, followed by sensory and motor systems, followed by circuits that interpret sensory information to produce motor outputs (this is where awareness of things like pain would first come up), and lastly, executive functions that control whole patterns of behavior and higher-order decision making.

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Which theory has more evidence, humans appeared in Africa 200,000 years ago, or there were already humans in Europe at least 210,000 years ago?
This theory
Modern humans originated from a woman who lived in modern day Botswana
says

Every person alive today descended from a woman who lived in
  modern-day Botswana about 200,000 years ago

And this finding states
Piece of skull found in Greece ‘is oldest human fossil outside Africa’

A broken skull chiselled from a lump of rock in a cave in Greece is
  the oldest modern human fossil ever found outside Africa, researchers
  claim.
The partial skull was discovered in the Apidima cave on the Mani
  peninsula of the southern Peloponnese and has been dated to be at
  least 210,000 years old.

Which certainty these findings have? Which one are we supposed to believe?
The question of the topic is, which theory has more evidence, humans appeared in Africa 200,000 years ago, or there were already humans in Europe at least 210,000 years ago?

I don't necessarily see a contradiction in both quotes: There were humans in Europe 210'000 years ago, but their female offspring do not/little contribute to todays human gene pool.

Considering even your linked article says the skull piece date is only preliminary results that have not been independently confirmed I would say it is the weaker one.

Mitochondrial Eve https://en.wikipedia.org/wiki/Mitochondrial_Eve does not mean "first woman" or first humans. "Every person" refers only to the matrilineal line. See also "pedigree collapse" by which everyone before a certain point will either be the direct ancestor of everyone or the ancestor of no one.

I voted to close this as "needing details or clarity", because the question as asked is entirely based on a misunderstanding as noted in comments. Revising the question ask more broadly for an explanation would solve this.

I disagree with the close-voters. I think this post should remain open. The main question (the one in bold) seems perfectly legitimate regardless of the comments (which are somewhat tangential given the main bolded scope of the OP's question). The OP has demonstrated prior research, has formatted the question decently well, and has asked a question that can receive non-opinion answers. The bolded portion of the question is not unclear (as close-voters are suggesting) and can be understood regardless of the context of the question or comments.


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What is this grasshopper doing?
I spotted a grasshopper standing on a pavement with a long sting placed in asphalt. I also recorded a video of it moving:
https://youtu.be/JoDdg2yUuYo
What is it doing?

It's its ovipositor & it's trying to dig a hole to lay its eggs.

"How Do Grasshoppers Dig Holes to Lay Their Eggs? After breeding, female grasshoppers dig a hole in the ground in which to lay their eggs by using a special tube in their abdomen known as an ovipositor. The ovipositor is first used to dig the hole, and then to deposit the eggs one by one into the hole"

Probably not having much success on tarmac, did it eventually move onto soil?

Interesting! I didn't see anything left in the pavement holes. Are its eggs visible to human eye? Yes, after a while I pushed it a bit since I didn't want it to stay on the road and it jumped onto the soil but I didn't observe it anymore.

@camillejr : Unless it found a deep enough crack in the tarmac it probably didn't lay anything there, not if it couldn't drive it's ovipositor deep enough, most likely laid its eggs in soil after you moved it.

@camillejr : They should be visible yes.


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Is cannibalism part of mainstream food-chain?
There are some species who sometimes eat their own kinds. Is this cannibalism considered their regular food? Do the link in food-chain for those animals make a loop on themselves?
Can this statement: "Food chains are found within the population of a species." be held true?
Disclosure: The above statement was part of a question that asked to identify the correct among statements. I tried to find relevant content in books and internet but couldn't find any. I'm not trying to get my assignment solved, but I want opinion on cannibalism and it's impact on food chains.

A food chain is a linear network of links in a food web (wiki). If you consider species as the nodes of the network, cannibalism could be represented as an edge that connects the species whit itself. This makes the network non-linear, So I suggest to used food web instead of food chain I think your statement can be true if you consider individuals of a given cannibalistic species as the nodes of your network.

Cannibalism can be found across most animal groups. For some groups of organisms (e.g., spiders, fishes) cannibalism can be common within a single generation. Sometimes it will be between siblings, but more often with other members of their species.
As @heracho pointed out, from a network/food web/flow-diagram perspective, yes, cannibalism is repressed as a negative feedback loop on itself.
Evaluating the statement: "Food chains are found within the population of a species," I interpret is as, within species, there are subgroups that consume subgroups, that consume subgroups. You'd need at least 3 levels for it to be considered a chain (i.e., you don't have a chain with two species/a single link). Cannibalism would be a single link/two species, and not considered a chain. As to whether or not chains exist within a species, I suspect it is not common if it exists at all. If it did, I would guess it'd be found in a group like fishes where prey are often size dependent.


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Plant identification and toxicity
What type of plant this is and is it poisonous (and, if so, in what quantities)?
The pictures were taken at Gullane Bay, Scotland. The plant is widely present in that region.

This is common sea buckthorn, Hippophae rhamnoides. The blueish leaves and the orange berries are unmistakable.
It occurs mainly in coastal regions, but is also cultivated throughout the world. The berries are processed to all kinds of food.
In their natural habitat in Northwestern Europe, the berries serve as a food source for migrating birds that fly from Scandinavia to the UK or the Netherlands. However, because the berries are often rotting and contain alcohol in september, sometimes drunk birds can be observed.

Thank you very much for this comprehensive and informative answer.


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Non-Salticidae with °oo° Eye Arrangements
Since childhood, I've always thought of the °oo° pattern of four frontmost eyes as iconic for spiders (note: the pattern does not account for any additional eyes or lack thereof further to the sides or back; also, title font seems to make the °'s relatively smaller than the main text's font does - this was not intentional). And yet taking a look at a couple of eye-based family identification tables, it seems that the above pattern is the go-to sign of a jumping spider.
Is this pattern unique to salticidae, or are there other groups of spiders with the four foremost eyes matching such a pattern (either four equal-sized eyes, or the secondary ones slightly smaller)? If the latter, what groups sport a similar look?

It is pretty much unique to salticidae, although I did find some similar eye arrangements in sicariids and scytodids.
Salticidae:

Sicariidae:

Scytodidae:

Image source


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Are olfactive indicators always the result of inadequacy in sanitation?
Question
If you can smell the scent of food in a thoroughly cleaned container, does that imply trace amounts of food particles remain?
Scope
It goes without saying that our sense of smell is commonly used in helping identify undesirables in day-to-day life, and as such it's understandable to correlate certain smells to hygiene effectiveness.  However, I'd like to definitively understand whether or not the presence of odorants unequivocally indicates ineffective or insufficient sanitation (in particular, on direct food-contact processing utensils and containers in a commercial/industrial environment).  E.g., coffee mugs with lingering scent of coffee despite repeated washing.
From the standpoint of HACCP/HARPC, I've always been slightly curious about the absence of "smell" as a modus operandi for pre-operational inspection (visual is the go-to).  I've always made the assumption that it simply isn't a reliable sensory indicator (despite visual being the same, in that sense), but I'm not fond of assuming.  I have a physics background, but I am unfortunately a bit lacking in biology / chemistry knowledge (beyond food safety-related microbiology).
Parameters
I'd like to understand from a scientific stand-point: is there an exclusively causal relationship between the two?  Are there possible scenarios where we can detect odorants despite having met sanitation performance standards?  For the sake of this question, I'd like to preclude the hypothetical possibility that "there were traces of debris/microbiological activity/etc., only they were within the tolerable limit defined".
I'm sure there might be a lot of complexities I am glossing over in my question, for which I apologize; e.g., I am aware in the framing of my question, I am holding some prejudice that the hazards of concern are microbiological -- whether pathogenic or not -- wherein the results from an adenosine triphosphate swab may be used as a quantified measure for overall activity.  For the sake of keeping this question from becoming too technical and convoluted to answer, and to also simplify and make measurable the criteria for "sufficient sanitation", please advise from the microbiological stand-point, but if relevant please advise from other standpoints as well (under HACCP/HARPC, the remaining potential hazard categories would be physical and chemical [includes radiological]).
Thank you!

Well that's discouraging to see.  May I ask why the down vote?  I even made sure to carefully read through the help pages here and here and thought I covered all my bases...?

My impression is that someone in the past day has felt like downvoting a significant percentage of recent questions, so the downvote for this question is about par for current submissions.  The question has also garnered a close vote, with close reason "unclear what you're asking", which IMO is not terribly off target.  Despite the amount of verbiage (also perhaps in part because of it), what you're really asking doesn't seem all that clear.  Not that I could answer anyway, but I wonder: any smell? Inadequate cleaning for what? "industrial" when the example is coffee scent from a coffee cup?

Sorry about that!  This is from the standpoint of sanitation at food processing facilities, I work as a food safety practitioner and document coordinator.  The background might be very specific, probably not many people will know what it's like to work at a USDA inspected food plant, hence maybe the terminology I'm using could sound a bit unfamiliar.  What I'm asking though is more generalized and I think can be answered by the community here.  Let me rephrase it: if you can smell the scent of food in a thoroughly cleaned container, does that imply trace amounts of food particles remain?

Or rather, one would assume "yes" in most cases, but are there cases where detecting a scent does not equate to presence of particulates that remain on the surface due to inadequate cleaning?

@Arctiic Trivially, if you detect an odorant then (unless you are imagining things) some of that odorant must exist. How much depends on the particular odorant and who is doing the smelling. From that point, from a food-processing standpoint it depends more on standards than biology, which I think is why some people have issue with the question.

@BryanKrause thank you for expanding on that.  The reason I posted in the Biology community is due to my own lack of basic knowledge on how odorants work; when I say "particulates", I'm referring to protein/lipid/other particles that can and should be removeable following standard wash procedures, of which the ones for concern would be those that would contribute to microbiological growth post-lethality treatment.  With that in mind, I'm unclear as to whether odorants can be, for instance, made up of x type of molecules and have no significant impact to microbiol proliferation, etc.

So in the coffee mug example, if I can still detect the scent of coffee -- the odorant -- then does that signify leaving it at room temperature for 8 hours, I would see a higher TPC count swabbing as-is, versus if I washed it another x amount of times until no detectable scent remains?  Note: I work with meat products and have no idea what risk category coffee grounds have under biological hazards, so that may not have been the best example, it was just the first thing that came to mind.

@Arctiic Nothing left open is sterile. Even a completely clean glass will eventually be contaminated with bacteria, mold spores, etc. This is why I say it depends more on standards than biology: if you want something to be sterile, you have to actually sterilize it which includes sealing it from the outside world in some way (for example, canning processes reach sterility or at least near sterility). However, that level of cleanliness is not necessary for food preparation that is not meant to be kept very long term, so there are standards for food prep cleanliness that are short of sterility.

@BryanKrause Yes, I understand that, our current testing standards are:
APC <100,000 CFU/g FDA-BAM CH.3
Coliform <200 CFU/g AOAC 991.14, 989.10
CP Staphylococcus <10 CFU/g AOAC 2003.07/0.08/0.11


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Scientific terms for front-brain, mid-brain and back-brain
I am looking for a (semi-) scientific way of phrasing "front part of brain" (part 1), "middle part of brain" (part 2) and "back part of brain" (part 3) as denoted in the attached picture.
I would (VERY!) loosely define these parts as:

front: everything in front of the ventricles
mid: approximately at the same height as the ventricles
back: behind the ventricles

I need this to qualitatively describe some results I have.

Note that this is different than forebrain, midbrain and hindbrain (which is the main result that google comes up with when searching for this).
(edit) Additional context: I have a method that selects a certain background volume in the brain. These background volumes are then used to make a segmentation. The placement of these background volumes seems to correlate with whether or not the segmentation is "good" or "bad". "Good" segmentations seem to correlate with backgrounds placed in the "mid-brain". "Bad" segmentations seem to correlate with background volumes places elsewhere.

Welcome. What's the context of the terms? I mean, what do you wish to explain? Chances are big there are no established anatomical terms for what you wish to describe.

Since you are working with 3D data, why not segment them into lobes? You have 4: frontal (front), occipital (back), temporal (lateral middle) and parietal (top middle) lobes. If you really must have three only, group the middle two together.

You have sulci (singular: sulcus) as references which you can naturally use as topographical borders for segmentation.
You can also define your own regions, provided that they are universal. I see no reason why not to define your own regions. You can define the arm as ending at the wrist, or including the hand. It's all semantic, and what matters most is to be clear with your definitions, not inflexibly adhering to preconception. You can use any gyrus or sulcus to define your arbitrary areas, pick however you like, with the knowledge that it must be suitable across all your samples and not confound your data in the end:

thanks, this helps. I decided to do it based on lobe/part of lateral ventricle it is adjacent to.

Short Answer

Anteroventricular coronal segment

Paraventricular coronal segment

Posteroventricular coronal segment

Long Answer
As indicated by @AliceD in the comments, I'm not sure there are technical terms to describe these regions per se.

Of greatest issue is how imprecise you're describing their cutoffs. Without citing very specific brain region/anatomy demarcations, any chance for proper technical vocabulary is minimal. (even broad brain divisions have defined boundaries)

Although something specific/technical is not really appropriate given your imprecise approach, I think some sort of general regional approach could be adopted:
So, what you have drawn are three mostly arbitrary coronal segments of the brain (i.e., three regions divided by 2 frontal planes).

You could simply refer to them as the anterior, posterior, and middle coronal sections or segments.
Or, I suppose you could also say pre-ventricular, ventricular, and post-ventricular coronal segments to place them in the context of the ventricles.

Though, perhaps you could create even more precise affixed terms: anteroventricular, periventricular, and posteroventricular coronal sections.

though, perhaps paraventricular could also be used vs periventricular, since your middle segment extends beyond the immediate perimeter of the ventricles.

Again, the above is stated based solely on a broad application of these generalized affixable terms. I am not commenting on their appropriateness or possible conflict with any current usage of any of these terms to perhaps clinically refer to more specified regions.


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Does our brain use up more ATP after smoking cannabis?
kind of an amateur here.
If the firing of the neurons' signals uses up some ATP, and smoking cannabis makes them fire off more quickly, do our brains use up more ATP to sustain that rapid firing?

The Biology.SE community has agreed that questions that show little or no prior research effort are off-topic on this site unless you have shown your attempt at an answer. Please [edit] your question and tell us where you've looked for answers, what you do know about the topic, and where exactly you still have questions. In particular, it's helpful to cite references for claims in your question.

considering that it can hasten heartbeat and breathing, https://medicalxpress.com/news/2017-08-brain-cannabis-oxygen.html

IV THC injection increases glucose metabolism in chronic cannabis users..see https://www.researchgate.net/profile/Linda_Chang2/publication/5944014_Functional_Imaging_Studies_in_Cannabis_Users/links/5431fc150cf27e39fa9f9880.pdf


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Why are sea dwelling mammals less aggressive than land dwelling mammals?
Many mammals on land seem to be quite dangerous to humans: e.g., tigers, lions, elephants, hypos etc. However, their sea-dwelling counterparts (e.g., orcas, dolphins, sea lions, whales etc.) are relatively friendly to humans (and in contrast to say sharks). Is there a simple reason for this?

Is there an objective way to measure friendliness of wild animals?

There is only one sea mammal specialized in eating seal sized prey and mammals, orcas. Why only one? that's tough, it's the solution to your query. Land based mammals prey substantially on large mammals, bears, big cats, wolves... When mammals size up another animal they think: "what is that animal shape doing? is it a food or a monster?" and "what is that face?" when they look at other animals. When sea mammals sea us they think "that's an alien from another world, he swims like a clown but his face is cool"

More encounters on land
There are more land animals that meet humans walking around than there are sea animals that meet humans swimming around. If fewer attacks happen on humans in the sea environment, it might just be because there are fewer encounters with marine mammals than with land mammals.
Greater species diversity on land
In your list used as example, you cherry-picked a few aggressive(-ish) land mammals but the vast majority of land mammals are not aggressive toward humans. The fact that there are no marine mammal that are aggressive toward humans might just be because there are too few fewer marine mammal species.
Pseudoreplication and phylogenetic signal
I would argue that your sample size is not as large as you might think. There are only four lineages of mammals that evolve to live in the seas. There is therefore a phylogenetic signal and ignoring it would be a problem of pseudo replication.
For example, I could very well think of territorial behaviour (which is where a lot of aggressive behaviour comes from) as having a strong phylogenetic signal.
Why considering only humans?
Your post title talks about aggressiveness in general and the content of your post talks about attacks against humans. It sounds that considering only attacks against humans to be very unfair. Orcas, typically, are fierce and violent predators although no orcas have ever attacked a human in the wild.
Are they really that friendly to humans?
There has been a number of attacks in captivity (well known cases with orcas). Also, there have been a number of whales attacks against boats (according to this BBC article).
In short...
In short, I think your comparison is unfair. I think you are looking for an explanation for a pattern that does not really exist.

I think there are actually 4 lineages of marine mammals: cetaceans (whales & dolphins), pinnipeds (seals & walruses), sirenia (manatees and dugongs), and mustelids (sea otters).  Maybe 5, if you include polar bears - which aren't all that friendly to humans.  Wikipedia has a diagram: https://en.wikipedia.org/wiki/Marine_mammal

@jamesqf Thanks for correcting! I forgot sirenia and the sea otters. I edited the post

Another example of a predatory cetacean would be the sperm whale.  But since they prey mostly on squid that live at depths of 300-800 m or more, you are not in much danger from them.  Unless you are Captain Ahab, of course - and that was pure self-defense on Moby Dick's part :-)  (Yes, I know that's fiction, but it was inspired by actual events, notably the sinking of the Essex: https://en.wikipedia.org/wiki/Essex_(whaleship) )

They actually aren't less aggressive than terrestrial mammals. I've heard a lot of biologists talk about this weird trend in marine mammals (and more or less only marine mammals) where for some strange reason, marine mammals have this weird predilection for sexually assaulting other species. Warning, most of the below links are scientific articles or news sources reporting scientific articles, but they can still be a bit explicit due to the subject matter.

Bottlenose dolphins are well known for having sex with just about everything that moves, including other dolphins (of both genders), humans (there is actually a wealth of literature on this), their own parents, and other sea life, including the females and babies of other dolphin species (and the babies of their own, by the by). Gender, willingness, or even the fact of the other individual being alive need not matter. They've been known to drown baby porpoises due to assaulting them so hard, and then continue to have sex with the body. This isn't unique to bottlenoses but has also been documented to some degree in botos (Inia geoffrensis), dusky dolphins (Lagenorhynchus obscurus), and Hector's dolphins (Cephalorhynchus hectori). It hasn't been documented yet in orcas, though this is probably a tracking issue more than anything else.
There's actually some evidence that dolphins may not be attacking other marine life for any definable survival or directly Darwinian reason, but are doing it for fun (or, from an etho-evolutionary perspective, the play behavior of killing or assaulting other marine life gives dolphins practice for when they commit infanticide on their own kind). Dolphins, at the very least, are some of the few animals aside from great apes that are known to perform non-copulatory reproductive behavior for pleasure.
Sea otters are well known for sexually assaulting and raping female sea otters, and frequently they will do this to baby seals as well. They are so rough about it the females and baby seals often drown, and again like the bottlenoses the otters continue copulating with the body
True seals aren't perpetual victims of this, as grey seals have been observed sexually assaulting seals of other species
Elephant seals also get in on the act, though so far only with their own species.
Fur seals (a relative of sea lions, rather than true seals) have been observed chasing down and forcibly copulating with penguins. They sometimes eat them afterwards.

This is seemingly commonplace among marine mammals, and nobody really knows why. Some of it definitely seems to be purposeful rather than the result of misplaced instincts, at least the way the researchers in the primary literature listed in the articles linked describe it. However, you almost never hear about this among terrestrial mammals. The only thing I've heard close to this is how traumatized young bull African elephants have been known to kill adult rhinoceroses and try to copulate with the dead body, and in that case it's clearly not normal behavior for the species.
So in at least some ways marine mammals are violent in ways that terrestrial mammals rarely are, and at least some of this (in the case of dolphins) is directed at humans.


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What plant have I collected?
I have collected this plant from the soil in a park in Belgium. I thought it was a child of a plant which was growing nearby but when the leaves started to grow I realised it is a different plant.
When I was collecting it, it was at the stage of having only the seed leaves (still visible in the photo) which are elongated and about 2.5 cm long. In the park, on the ground from where I collected it, these plants were growing in large quantity close to each other. After about 1 week from bringing it home the leaves started to appear. Now about 3 weeks later the leaves are about 2-3 cm long.
Could you help me identify it?

Further clues
First of all, this plant is very abundant in the park but I can also spot it in other places, e.g. close to sidewalks within a walking distance from this park.
This is the plant in the original environment from where I collected it:

I could also find it growing in a pocket of a tree - this suggests to me that the seeds might have fell from a height, so this plant might be a tree (?)

The ground of the park is largely populated by wild garlic. Other than that, some nearby plants are a hornbeam and elderberry.
Here are some further photos of surrounding plants that might be a hint for you:

It might help if you also had the remains of the seed itself.

Unfortunately I don't have the seed. This weekend I will go to the same park and perhaps collect some further clues :)

Try to identify nearby trees also. Even if the the leaves do not match, this could be helpful information regarding the environment.

To help you start ruling out species: not Corylus avellana; not Robinia pseudoacacia (which both show up in your pictures). That cherry is of more interest, but I think your seedling is not quite representative of Prunus avium

Leaves make me think Acer is likely, and the presence of a decaying maple samara in your 3rd image is a giveaway that maples are nearby...

You definitely have a seedling with prominent cotyledons still present.
My initial guess is Acer pseudoplatanus (sycamore maple, or just called "sycamore" or "planetree maple" in parts of Europe)

 Source: Wikimedia
You can see a detailed image of an A. pseudoplatanus seedling here and a time-lapse of a seedling growing to the point of cotyledon release in Neil Bromhall's youTube video.
According to the range map available from Euforgen, A. pseudoplatanus is present (blue) throughout Belgium:

As for confirming nearby adults, you're looking for a tree that looks as follows:

 Source: Blue River Nursery
For more information regarding identifying the adult, please see Virginia Tech Dendrology

Scientific study of the cotyledons of this tree can be found from two New Phytology (76th issue) papers from the 1970s: Ampofo et. al 1976, pp 31-39 and Ampofo et al. 1976, pp 41-52

Wow, very interesting! I didn't expect it because the adult leaves are different. Thank you for solving the mystery! :)

@camillejr Sure!. But please go back and check to see if you can find a mature tree to confirm my suspicion or not.

No need to guess here, this looks very much like a seedling of A. pseudoplatanus (Gewone esdoorn in Belgium and The Netherlands). This is the most common Acer in Belgium. Other relatively common species are Acer platanoides and Acer campestre, but but their leaves differ and I've never seen these have seedlings this abundant.


text:
Can anyone please identify this?

We saw this leech like worm in Kerala, India. Can anyone identify it for us? I saw it today, 10th September. It's about 6 to 7 centimeters long. It was very still, didn't move while we went close and took a picture. Thank you.

Please [edit] your question and give us some more details. Most importantly, how big is that? Is it a centimeter? A meter? What time of year did you see it? What time of day?

It does not look like a leech to me. Looks more like a millipede. Did it have legs?

None that we could see.


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What pigment is responsible for the formation of blue skin color in some animals?
Not long ago I read about Vervet monkey. Here's picture:

My question is what causes this blue coloration of the scrotum? I don't mean evolutionary need  (e.g. attracting females), but what pigment or other factor is responsible for this color?

I've suggested an edit to your post; in the future please upload pictures rather than including links. Links are discouraged since 1) if they break they no longer add value to this post, and 2) they can be used to link to malicious websites. Thanks!

A related question about blue food that doesn't answer your question, but you might find it interesting: Why are so few foods blue?

Blue coloration in animals is caused by structural color rather than blue pigments. In the case of vervet monkeys and other mammals studied this is due to collagen fibers in the skin being arranged with a regular spacing that results in blue wavelengths constructively interfering while other wavelengths destructively interfere1.
This "news" article in Science discusses this phenomenon and mentions Vervet monkeys.
Reference:
1: Prum, R. O., & Torres, R. (2004). Structural colouration of mammalian skin: convergent evolution of coherently scattering dermal collagen arrays. Journal of Experimental Biology, 207(12), 2157-2172.

Excellent! (+1). It's always nice to see such useful primary literature cited here on Bio.SE! Can you elaborate a tiny bit more from the paper (i.e., describe the tissue arrangement more explicitly etc.)? -- Not necessary, but I think doing so would make the answer stand better on its own (in case links died and someone can't get access to the paper).


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What's up with this leaf?
This cool design was "tattooed" on this leaf.
I found it on the windshield of my car.
What's up with it?

That is the work of a leaf miner. A leaf miner is the larval stage of an insect that feeds on the inside layer of leaves. Notice how the galleries (tunnels) start small and then get larger as the larva matures? Most leaf miners are moth larvae (Lepidoptera)
https://en.wikipedia.org/wiki/Leaf_miner

I love this caption from the wiki page photo: "Leaf with minor miner damage".

@pyro Since the miner isn't an adult, you could even describe it as minor miner minor damage!

This leafminer is a moth in the genus Phyllocnistis (Gracillariidae). If you knew what plant the leaf came from, the moth could probably be identified to species. The marginal leaf fold at lower right is where the mature larva has spun its cocoon.
Incidentally, I'm just finishing a complete guide to the known leafminers of North America. There are many species left to be discovered though!


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What spider is this in Idaho?
I have killed maybe 5 of these solders as I have a 3 year old and dont want her bit.
Details :

Whitish top; brown legs; striped maybe yellow or white on the butt with black
Size of a penny
Seen them all times of the day. Summer (July)

Kinda reminds me of the ant-mimic spider but I am unsure.

And a close up:

Should be able to zoom in quite a bit. Just hold CTRL and hit the plus symbol.

If user22020 is 100% sure that's a hobo spider, then I'm 101% sure that's a stealthy ground spider. The source of user22020's picture actually labeled it as such.

 It's definitely in the ground spider family, just like Parsons spiders.
Hobo spiders and barn funnelweavers are more well-known, but both are brown, not black and white, and have vastly different patterning than yours. Stealthy ground spider are not famous because they, like most Idaho spiders, are not dangerous.

Welcome to Biology.SE! Can you elaborate why you think your identification is correct? For example, discuss the key features that helped you come to this conclusion and provide references that support your assertions. ——— You might also want to take the [tour] and then consult the help pages for additional advice on [Answer] questions effectively on this site and then edit your answer accordingly. Thanks!

It seems to be a male barn funnel weaver, according to a quick google search. The main part of this picture that leads me to believe that is the first segment of the leg, closest to the body, is darker than the rest.
This is the a male barn funnel weaver, with the same darker segments. And yes, I looked at the list specifically for Idaho

Answers to species ID questions need a lot more content than this. You need to convince us that your ID is correct, explain why that ID applies over other IDs, and hopefully provide some convincing pictures. Note that species ID is quite difficult, especially for arthropods due to incredible diversity and many similar body plans for distinct species (and even genera).


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How dirty are bugs? And is it okay if they touch food?
Sometimes I see people throw out an entire drink or bowl of food because a small bug was in it. Are they justified in doing this? Is there enough bacteria on common species of bugs (like ants, flies, beetles, dragonflies, caterpillars, moths, etc) to warrant any kind of health concern for a larger amount of food than what the bug was in contact with, or at all?

Most people don't care about hygiene. It's mainly the "eww" factor. However common houseflies often sit on fecal matter, so that's an issue though.

You actually eat a lot of insects without even knowing it:
https://blogs.scientificamerican.com/but-not-simpler/i-hate-to-break-it-to-you-but-you-already-eat-bugs/

Well, first of all you should consider that insects and generally animals don't have so much hygiene, like us humans. Some of them, let's say the ants, yes some kind of hygiene is present, but not in the human degree. In fact, most insects are responsible for the most dangerous deseases in the world such as malaria , yellow fiver, sleeping sickness (espacially found in Africa because of the tsetse fly) and many kinds of encephalitis. This article claims that most of insects are carriers of deadly deseases. Also, about the second part of your question, you mentioned " If it is okay for bugs to touch food"... Well the answer is ofcourse no, because you don't know:
1. what the insect was touching before it "lands" to your food
2. If it has dropped any fecesto your food
3. And last but not least if the insect layed any kind of eggs to your food.
4. Some insects carry fungi that if a human being consumes them he might have serious problems, because some fungi are responsible for poisoning or infection.
The third one that I mentioned is responsible for the most cases of Tapeworm infection. This means that the eggs and larvae pass straight to your digestive system and create the infection. To sum up, unknown factors (like bugs) must not touch our food, because there is a chance of infection. To help you here's a wikipedia list that shows the most easily transmitted diseases to humans fron insects: List of diseases caused by insects.

A lot of the carried disease you mention depend on insect bites, not food contamination.

If bugs are really that bad, how come so many people eat them raw or nearly raw without getting negative side effects?

@DaneJoe Each human has different hygiene rules....

@The_Mad_Fish No matter who you are, if you just eat a slice of raw chicken that's been sitting out for a day, you will get sick. This is not dependent on some cultural preference, there is at absolute statistical answer at least for individual species of bugs.

This answer is misleading; the mosquito is the most deadly insect by numbers on the planet, and it doesn't result from landing (or pooping) on your food.


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What is the meaning of pygo and pagus in the word pygopagus?
I know definition of the disease pygopagus but I want to know the meaning of separate parts of it, in fact what's the meaning of pygo- and -pagus in terminology?

I'm voting to close this question as off-topic because it is a question of ethymology and should be asked on english.SE. Note also, that biology is not medicine anyway. So,if you were looking for a definition of this disease, you should ask on Health.SE.

Firs of all, etymology not ethymology! as I mentioned I know the definition so I am not looking for the definition of disease! and as far as I know prefix and suffixes are studied in terminology, so I wanted to ask that is pagus a suffix or not?

First of all, First not Firs! Joking... thanks for correcting me on that. I'm sorry if you thought I said you were looking for a definition. I said if you were looking for a definition of this disease, you should ask on Health.SE. It was only indicative. Terminology (study of the terms of their use) questions (about terms used in biology) are on-topic. I don't think etymology questions (the study of the origin of words) are on-topic. I am voting to close. I think your question would be on-topic on english.SE or maybe linguistics.SE

Gr: Pygo/pyge (tail, rump) + pagus (fixed). Any decent dictionary will give you the etymology of the word.

According to Wiktionary.com:

pygo- means "rump" or "posterior" from Ancient Greek πυγή (pugḗ, “tail, rump”).

According to dictionary.com:

-pagus means "fixation" or "something fixed or solid" from Greek  págos.

So literally, pygopagus (or conjoined twins attached at the butt) means "fixed rumps".


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Is pith a ground tissue with no specialized function?
Here is a question from the book My Max Score SAT Biology E/M Subject Test (where the SAT is the exam taken by American high school students):

Ground tissue with no specialized function
  A. Xylem
  B. Phloem
  C. Cambium
  D. Bark
  E. Pith

Here, I can eliminate A, B, and D because these are dermal and vascular tissues while a ground tissue is what's between those.
As for the remaining variants, cambium is a tissue that gives rise to other tissues and is responsible for the plant's growth up and to the sides. Pith is a tissue in the very center of the plant stem and is responsible for storage of nutrients. While trying to understand the question, I even found info that it is a type of vascular tissue because it is involved in plant transport (https://www.quora.com/What-are-the-functions-of-piths-in-a-plant) although I'm not sure if it's correct (yeah, I know that Quora is not the website with absolutely credible info).
So, as I can see, both cambium and pith have their function.
Then, I decided to determine whether they are a kind of ground tissue. Pith definitely is a ground tissue, according to its definitions. However, I could not find what kind of tissue cambium was considered to be.
With all that said, I can't be sure to choose either answer. First, both tissues have their functions. Second, pith is a ground tissue, and cambium is undetermined for me.
Here is the answer, however:

E. Pith is a source of unspecialized ground tissue that adds structure
  to a stem at the very center.

I can't be sure about this answer because unspecialized means "not designed for a particular purpose." But, as I've pointed out, both pith and cambium have their purposes/functions.
Please explain why pith is written to be unspecialized. Is it because "storage" is not an "active" function like growth or transport; this tissue just exists and is able to store different substances in addition to that?
Also, is cambium a ground tissue or some other type (dermal, vascular)?

Short answer: it's not the greatest question.
Long Answer:
So there are three primary tissues in a plant: ground tissue, dermal tissue, and vascular tissue. See below for how they sort out:

However, some sources refer to the tissues of plants slightly differently, and indicate that the three basic tissue types are parenchyma, collenchyma, and schlerenchyma.

Example: "Botany: A Lab Manual" by Pfluger 2014:

The three fundemental tissues of plants are parenchyma, collenchyma, and sclerenchyma

Since these are all "ground" tissues, this approach to classifying plant tissues would suggest that all plant parts consist of some kind of ground tissue (including all the plant parts you mention in your post). In fact, this is often the case...

Again, from Pfluger 2014:

They [parenchyma] can be found in virtually any part of the plant and are the most common cell type in a plant.

Of the parts you mention, xylem is "specialized" to move water through the plant via tracheids, pits, and vessel elements; phloem moves sugars/sap through sieve tube cells which are supported by companion cells; cambium acts in secondary growth of wood and bark via the vascular and cork cambia; and bark is a water-proof protective layer.
However, "pith" is simply the central parenchyma cells in the stem, and therefore are primarily just used for storage like "all unspecialized" ground tissue.
As for cambium: from here:

Interfascicular cambium differentiates from parenchyma or collenchyma cells located between the vascular bundles (mainly in stem)


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Can an Ichthyologist identify this Canadian freshwater fish?

This will be very simple for a lot of you! But I been getting mixed answers about his catch. Is this a chinook salmon or brown spotted trout? Caught in Angus, Ontario, Canada. (Hwy 90 Bridge)
I appreciate the help!

Caught in a upstream river in Angus, Ontario (Hwy 90 Bridge)... Canada. This shot was from yesterday, Sunday sept. 17, 2017

Judging from the curved caudal (tail) fin, which is more square in brown trout, this appears to be a chinook salmon. The mouth also appears to be black whereas in brown trout the mouth is white.
Sources: Michigan Department of Natural Resources


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What is this tree that displays sycamore like characteristics but appears to be too small?
I have been wondering about this tree:

It's bark/leaves make me think it's a sycamore, but it seems too puny. I don't think they'd plant a sycamore there... What is it?
The tree is in a park/residential area in Orange County, Southern California.
Reasons I think it looks Sycamorish:

Alternate leaves
3 lobes
Mottled/patchy/peely bark

https://www.thoughtco.com/identify-maple-sycamore-yellow-poplar-sweetgum-leaves-1343480

When dealing with species ID, Africans indicate the country and the continent, Americans indicate the county and an abbreviation to indicate a region within the state (now corrected) $\ddot \smile$ I personnaly did not know SoCal meant South California. +1 otherwise!

probably the london planetree. that is my best guess

Adding photos of bark, and fruits/flowers if available might help.

"Mottled/patchy/peely bark" suggests me https://en.wikipedia.org/wiki/Platanus

This is very likely a London planetree (Platanus × acerifolia), a hybrid species of Platanus often planted in cities.

 Source: Cuyamaca College

 Source: Wikimedia
The tree is a hybrid between Platanus orientalis and Platanus occidentalis (the sycamore tree), and has characteristics intermediate between the two species.

Smaller (heights of only 20-30 m vs 30-40+ m for parent species).
More deeply lobed leaf than P. occidentalis but less so than P. orientalis
Seed balls typically two per stem (one in P. occidentalis, 3-6 in P. orientalis)

Note: seed "balls" = aggregate of many small seed-like fruits called achenes

VERY OFTEN PLANTED IN URBAN AREAS

Because it's very tolerant of atmospheric pollution and root compaction

Description:

Leaves: alternate, simple, 3-5 lobes, maple-shaped, 10–20 cm long, 12–25 cm wide
Bark: pale grey-green (or brown), smooth and peeling (sometimes not peeling)


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Why is this Cuscuta compacta purple?
I was recently browsing the web and came across this site abut the compact dodder.

https://gobotany.nativeplanttrust.org/species/cuscuta/compacta/
The image used to identify the plant shows it as purple. This struck me as odd, as those are usually a greenish-yellow. Why is this plant purple? Is it a special sub species? Is it perhaps another type of dodder entirely, and gobotany simply messed up? I think this image might actually show the Cuscuta glomerata, but I'm not sure. Please explain this discoloration. Thanks in advance!

Is this another gold-white/blue-black dress moment? I dont see any part of the plant in the foto as purple. The ground in the background is blue. My brain interprets this as photo being taken in havily purple tinged lighting, posibly grow lights. My brain performs sort of light balance and the plant appears to me yellow/brown (fruit) and green (leafs). Only part that seems slightly purple is the leaf underside. What part of the plant do you see as purple?

the Genus Cuscuta has over 200 species varying in color from yellow, to orange, and purple (sometimes but rarely can also be green).
The organism in the photo is not likely to be a subspecies of the usual dodders you find in your area, instead it is likely to be a different species entirely (while still belonging to the same genus).
The rope dodder (Cuscuta compacta) is very possibly the species you are looking at. However, I am also convinced that Cuscuta europea is a possible candidate, particularly due to this photo of the species that I got from the European Nature Information System (EUNIS) web site:

I must admit that I do not know nor have access to photos of all the different species of the Cuscuta genus to make a truly objective analysis of your image however I hope this information as a minimum leads to some new insight on the matter.


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What specimen of caterpillar is this?
Early this morning, I found this beautiful caterpillar specimen crawling over a leaf:

This specimen was found today morning (spring season) in Brazil at Porto Alegre City 30°01′59″S 51°13′48″W. With approximately 1 Inch long.
What kind of specimen is this?

This appears to be a "Monkey slug" caterpillar (Phobetron spp) of the family Limacodidae (or slug moths).
According to these sites (here and here), caterpillars of this type are commonly referred to in Portuguese as "Lagarta-Aranha" (or "lesma-macaco") [literally, "spider caterpillar" and "monkey slug" in English].
The most common Phobetron species I can find in Brazil is Phobetron hipparchia.

The caterpillar of this species appears to be quite variable (ranging from browns to reds in color) as is made apparent by here, here, and here

 Phobetron hipparchia  (Source: http://caterpillars.unr.edu/)

They're quite interesting as adults as well: https://www.flickriver.com/photos/140413390@N06/39589933685/


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Leaf parasite/pathogen species identification
What kind/species is this?

Brasília - DF - Brazil (Winter)

These are telia of the telial stage of a pathenogenic fungus called a rust.
I wrote a similar post about the aecia (a defferent reproductive stage) of a similar rust species in the US many years ago here
I'm less familiar with Brazilian organisms, and without a full image of the plant (or more ideally ID of the plant species) or more circumstancial info provided by OP, IDing this particular rust to species would be annoyingly difficult.
Lucky for you, there is a publicly available key (Hennen et al 2005) for Brazilian species (link is PDF):
Catalogue of the species of plant rust fungi (Uredinales) of Brazil.
I encourage you to both update your post with more detail (especially regarding location and type and image of plant) and to start working through they key. After an update, I'd be willing to dive in deeper...


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Photolysis in the Light Reactions of Photosynthesis
I'm a bit confused concerning photolysis. During the light reactions, photons are used to excite the chlorophyll molecules so they are passed to the primary electron acceptor. The electrons initially come from a split water molecule. Is water split by the photons?

Does this answer your question? Photolysis of Water?

@tyersome the post you link to is about photolysis, but that post is about the chemistry of the process. Another post, Photosynthesis: What Powers the Splitting of Water?, appears to also ask about photolysis but from the perspective of the role of ATP. This current post, though related to the aforementioned posts, seems to be -- at least in my understanding -- more focused on the mechanism involved. I have provided an answer below that reflects this interpretation of the OP's question.

Regardless, the OP should sufficiently have received a response to their question from any of these three posts which are now linked as being related. Thanks.

A catalytic site on a subunit of Photosystem II is responsible for splitting water via photo-oxidation. This site, called the Oxygen-evolving complex (or OEM), uses energy from sunlight (which is converted to electrochemical potential energy in the photosystem's reaction center) to accomplish this task.

 Source: Wikimedia
See Barber (2012)1 for an explanation. The abstract (my emphasis):

The oxygen in our atmosphere is derived and maintained by the water-splitting process of photosynthesis. The enzyme that facilitates this reaction and therefore underpins virtually all life on our planet is known as photosystem II (PSII), a multisubunit enzyme embedded in the lipid environment of the thylakoid membranes of plants, algae, and cyanobacteria. During the past 10 years, crystal structures of a 700-kDa cyanobacterial dimeric PSII complex have been reported with ever-increasing improvement in resolution--the latest at 1.9 Å. Thus, the organizational and structural details of its many subunits and cofactors are now well understood. The water-splitting site was revealed as a cluster of four Mn ions and one Ca ion surrounded by amino-acid side chains, of which seven provide ligands to the metals. The metal cluster is organized as a cubane-like structure composed of three Mn ions and the one Ca2+ ion linked by oxo bonds. The fourth Mn is attached to the cubane via one of its bridging oxygens together with another oxo bridge to an Mn ion of the cubane. The overall structure of the catalytic site provides a framework to propose a mechanistic scheme for the water-splitting process and gives a blueprint for the development of catalysts that mimick the reaction in an artificial chemical system as a means to generate solar fuels.

My understanding is that we are still not totally certain how this actually works...

Cady et al. (2008)2 wrote a review in 2008 of various functional models trying to explain the chemistry of the oxygen-evolving complex of photosystem II.

A quick Google Scholar search reveals plenty of proposed mechanisms published since.

Most currently proposed mechanisms do, however, incorporate the 4 oxidation steps proposed by Kok et al. (1970)3 (now referred to as the Kok Cycle, or Kok's S-state cycle).

From Kern et al. (2013)4:

The oxidation equivalents generated by the absorption of four photons by the PS II reaction center are stored in the four consecutive redox states of a Mn4CaO5 cluster, known as the Si (i=1 to 4) states. The accumulated energy is used in the concerted oxidation of two molecules of water to form dioxygen (1) returning the catalyst to the most reduced S0 state in the Kok cycle (Scheme 1).

 Scheme 1 from Kern et al. (2013) explaining states of Kok Cycle.

You can learn more here.

Works Cited:
1 Barber, J., 2012, January. Photosystem II: the water-splitting enzyme of photosynthesis. In Cold Spring Harbor symposia on quantitative biology (Vol. 77, pp. 295-307). Cold Spring Harbor Laboratory Press.
2 Cady, C.W., Crabtree, R.H. and Brudvig, G.W., 2008. Functional models for the oxygen-evolving complex of photosystem II. Coordination chemistry reviews, 252(3-4), pp.444-455.
3 Kok, B., Forbush, B. and McGloin, M., 1970. Cooperation of charges in photosynthetic O2 evolution–I. A linear four step mechanism. Photochemistry and photobiology, 11(6), pp.457-475.
4 Kern, J., Alonso-Mori, R., Tran, R., Hattne, J., Gildea, R.J., Echols, N., Glöckner, C., Hellmich, J., Laksmono, H., Sierra, R.G. and Lassalle-Kaiser, B., 2013. Simultaneous femtosecond X-ray spectroscopy and diffraction of photosystem II at room temperature. Science, 340(6131), pp.491-495.


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What small insect is this?
Lately, lots of these little bugs have been lurking in my house in Italy. Should I worry?

I'm curious to know what they are.
For reference, the 2 cent Euro is 18.75 mm in diameter.

Possible duplicate of Bug Identification: Is this small tubular, black bug a bed bug?

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It looks like a carpet beetle larvae(Anthrenus verbasci) to me. This seems to fit considering you found it in your house, which is one place they are fairly common. I would not be able to tell you if you should be worried, I am not a biologist.


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The colour of aquatic plants found deep under oceans
I have read that many aquatic plants found in deep oceans are red in colour, however, I do not understand why. As red is the color which gets the least scattered it should be the only light available to them. Thus reflecting red light would deprive them of any light. Yet they appear to be in red color. Why is this so?

Would there even BE plants in the deep oceans, since there isn't enough light for photosynthesis below 100-200 meters?  NOAA explains why many deep ocean animals are red: http://oceanexplorer.noaa.gov/facts/red-color.html

@Deepakms you say I have read that [...] Can you please link to your source (even if it is not a peer-review paper)?

Is the red Colour the physical appearance or satellite imagery?

@Remi.b I read it in Class 12 NCERT Biology book, chapter on ecology.

Certainly,it was from NCERT. Also it is not just any plant ,but the algae.

You're right that certain wavelengths of light are more capable of penetrating deeper depths of water. However, it turns out, blue light typically travels to deeper depths than all other visible wavelengths of light (and red light does not travel deeply at all).

See my previous SE answer for more details about plant coloration due to this phenomenon.

So that leaves the question of why are these plants red?
Plant life itself cannot exist without the ability to photosynthesize, so actually no plants exist beyond a few hundred meters down. And in fact, many of these plants are still green (e.g., see here and here).
However, some red algae represent an example of a red "plant" (not actually a plant, but quite closely related) that can live fairly deep. According to the University of California-Berkeley:

red algae are red, "because of the presence of the pigment phycoerythrin; this pigment reflects red light and absorbs blue light. Because blue light penetrates water to a greater depth than light of longer wavelengths, these pigments allow red algae to photosynthesize.

Interestingly, this 'reddening' phenomenon is shared by many deep sea organisms, though more often for the sake of protection from predation.
Red light does not reach ocean depths, so deep-sea animals that are red actually appear black and thus are less visible to predators and prey.
See this NOAA page for more:

All objects that are not transparent or translucent either absorb or reflect nearly all of the light that strikes them. When struck by white light (containing all colors), a red fish reflects red light and absorbs all other colors.
The deeper you and the fish go, the less red the fish will appear, because there is less and less red light to reflect off of the fish. At 100 meters, red light does not penetrate and, at this depth, a red fish is difficult, if not impossible to see. Instead, the fish appears blackish because there is no red light to reflect at that depth and the fish absorbs all other wavelengths of color.

@theforestecologistTHANKS,for the answer;but I didn't understand why blue is able to penetrate better.Could you please explain it?

@Gerardo right, though it's actually more complicated than that. The taxonomy of red algae is still debated.  See here for a brief explanation. Regardless, I just simplified that discrepency here and just said "plant." I'll edit my answer to add a link to something to address  this,  though.

@Gerardo fair. And I tend to side with you. I've updated my answer to at least aknowledge this :p. I'll let these comments serve the purpose  of further acknowledging  this point  so as not to distract  from my answer (which extends beyond plants anyway).  And thanks for the dartmouth link.

To be honest, I should just go down the hall and ask  Max H. Hommersand his pinion about it :p


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Is spiders building webs on plants an example of mutualism or commensalism?
In one section of the GED study book I'm looking through to prepare myself for exams, they define parasitism, mutualism, and commensalism, and give examples.
One of the examples they give for mutualism is ants living in an acacia tree. The ants get a home, and they defend the tree.
One of the examples they give for commensalism is a spider building a web on a plant.
Is this actually an example of commensalism? This seems more like mutualism to me. The spider benefits from being able to put its web somewhere, and the plant benefits from protection from bugs (as the spider's web will catch them).
Is this relationship an example of commensalism or mutualism?

You're thinking too broadly and rigidly about these concepts -- both commensalism and mutualism are types of interspecific interactions.
Commensalism is when one species in a given interaction is benefited while the other is neither benefited nor harmed. In a mutualistic interaction, both species benefit from their interaction with each other.

Like any interaction between two organisms, these interactions can vary between individuals. Although some species pairs will consistently undergo the same type of interaction (e.g., shark and prey -- predation), some groups of species may vary in their paired interactions. This variation may result from two different scenarios:

Variation in interaction type between different species within a taxonomic group

E.g., one type of spider catches insects that don't harm the plant -- commensalism -- while another spider species catches insects that would harm the plant -- mutualism. In other words, not all spider-plant interactions are the same, and the interaction type may be dependent on the species involved.

Variation even from the same individual in different circumstances.

E.g., A spider catches an insect that doesn't eat the plant it's growing on (commensalism) but at another time it catches an herbivorous insect that does eat the plant the spider has built its web on (a mutualistic behavior). In this scenario, the interaction type between the same two species (even the same individuals) can vary based on circumstances.

Put differently, commensalism, mutualism, etc. are not behavioral traits, but interactions, and so are dependent on not only the species involved but the circumstances as well.
Note: To further complicate things, each given interaction can be qualified in various ways. For example, from Wiley ELS:

Positive interactions can be trophic and nontrophic, can act directly or indirectly (mediated by a third species) and can be symmetric (species have equal effects) or asymmetric (species have unequal effects).

For the scenario you laid out, the short answer is yes.
Like @theforestecologist pointed out, interactions can be complex and contingent.
Although, in the example you give, it can be easily tested: grow plants with spiders and without, and see if there is a difference in plant fitness. Fitness can be measured directly by looking at, for instance, the number and quality of seeds the plants in each group produces. But fitness can also be measured indirectly by looking at the amount of herbivory on the plants (e.g., scars), the number or area of leaves before and after the spider treatment, photosynthetic rates, etc.
If a fitness benefit can be demonstrated with both species involved, then it is considered a mutualism.

Great experimental/application point! +1. Very clear that this fitness experiment could be used to begin getting at the predominant interaction type. Thanks


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Leaf-curling type spider southeastern US
I have a spider in my backyard in Mobile, AL.  It seems to have sewn itself up inside of a living water oak leaf.  I tried googling it but only came up with this Austrailian spider that does a similar thing, but not exactly.  Notably, there is no attendant web, just the folded leaf container.  The leaf has been folded twice into a perfect little tetrahedral home.  Here is a picture... I didn't want to disturb her too much:

What species is this beautiful geometer?

Scott, please try to get another image of the spider -- one in which we can actually see the spider :p. Thanks

I would expect this to be an orbweaver, as I've seen numerous examples of leaf shelters for these spiders.  Usually, they're associated with a big orbweb, though.  It's not going to be anything with an unpleasant bite, though, so it should be fine to gently open up (maybe have a bowl underneath to catch the spider when she drops out) and expose the occupant for a photo.


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Re-Plumping Dried Insects
I have begun to display some of my soft bodied insects and as I am trying to rehydrate some of them that were plump in the abdomen, they appear to have shrunk and the bodies have sunk into themselves.  Does anyone know how to avoid this or what can be done to plump the bodies back up?

using a serynge of silicone?

"Soft bodied" can come from a number of conditions, but generally, soft bodied insects are kept in ethanol. Adult insects should not need any kind of treatment before being pinned. Nymphs and immature insects should be in ethanol, and I suspect this is what you have. However, they can be freeze dried for a nice effect. One technique that works for females that are full of fatty eggs (such as Orthoptera) is to make an incision on the ventral side with an exacto-knife, and scrape out the contents of the abdomen. Then stuff with cotton, and close the incision. I think you likely have immatures, which should be in ethanol, but this technique would work if you are careful.

Sorry, I may have not fully explained what I am trying to do.
I have just re-hydrated, pinned and dry mounted some rather large bodied insects (spiders and soft bodied leaf cutters and the like) and their abdomens are beginning to dehydrate.  I believe I had seen that you could inject them with something  (not sure what) and it would dry and keep the body in shape.  I was hoping for some suggestions.
Nothing like a caved in body to show your friends!

Also, I have tried Purell for a few black widows that I got as a gift, but they are starting to look as if they are fuzzy. I do not normally use ethanol, is there another suggestion of something readily available.  Thank you again... Jenn B

I guess if I were you, and did not have access to a freeze drier, than I would use trial and error. Try injecting different things on some common spiders you don't care about. Like silicone (as suggested above), or even Elmer's glue.


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Can anyone identify what is the name of this plant?
I found this plant on the side of the street in Melbourne, Australia. Looked like someone just removed it and threw it from their garden. So I took it home and planted it.
The plant had damaged leaves which I removed. (https://i.sstatic.net/htnbK.jpg)

Welcome to Biology.SE! If possible clearer, closeup photos (or a description) of the leaves and the stem from multiple angles might be helpful. In particular, I wonder whether the leaves thick (fleshy) and waxy like a succulent or are they relatively thin? ——— Please also take the [tour] and then go through the help pages starting with [Ask] questions effectively on this site. Thanks!

There are so very many succulents in the world (and you now have one in your garden!) Wait until the roots have established themselves well, then cut the stalks back to about two inches. You'll be able to post a better identifiable picture when it starts to grow back.


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What is this bug I found at my house?
I found it on my door. I live in Southeast Texas. What is it?

Can you include more information in the question itself (not as a comment). For example, the size, how fast it moved (if at all) time of day, time of year...

It looks like an insect larva, maybe a dipteran. The white tree-like structures on its side could be its trachea (respiratory system).


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What are the brain structures directly on top of the brain stem?
I have been trying to learn the anatomy of the brain, and some information on their functions, through an iPad app called 3D Brain.  Whilst going through the different parts, I have noticed that one area doesn’t seem to be mentioned.
If you look at the image below, you get the brain stem (colour highlighted and labelled).

Going from the brain stem upwards, I am then trying to identify the structures in medium grey which sit on top of the midbrain.
I have seen that the bulbous areas left and right are the basal ganglia.

What are the rest of the structures?  I would like to know what all the mid grey structures are in the first image, but I am especially curious to know what I have drawn around below.

Can I ask why I am getting downvoted?

I'm not one of the downvotes, but I think this question comes off as a bit under-researched and poorly motivated, while also being quite broad. Basically this approach to studying the brain doesn't make a lot of sense, and there are lots of sources besides this app to learn basic brain anatomy.

You're looking at many structures in this area.
The region directly above the midbrain is the diencephalon (meaning "across + brain"). From inferior to superior it's composed of the hypothalamus, thalamus, and structures that developed from a developmental region referred to as the epithalamus that include the pineal gland, habenular trigone, and choroid plexus. Between the hemispheres of the thalamus/hypothalmus lies the third ventricle (which may be "bridged" by a structure called the interthalamic adhesion).
Of each of these structures, only the thalamus and hypothalamus are truly visible from your images -- with the hypothalamus articulating with the midbrain and the thalamus emerging superior and slightly lateral to he hypothalamus. The following structures are also visible in your image:
The most inferior structure you see is the pituitary gland, while the "X" shaped structure superior to it is the optic chiasm with cut optic nerves anteriorly and optic tracts continuing posteriorly out of view.
It's not entirely clear, but I believe the two protruding structures posterior to the pituitary are the paired oculomotor nerves.
Finally, the two long ribbon-like structures that extend anteriorly are the olfactory tracts of cranial nerve I that terminate anteriorly in optic bulbs.


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What is an example of a plant species that is a halophyte with seeds that germinate quickly?
I’m doing an experiment on the effect of salt concentration on the germination of seeds from halophyte plants. What would be an example of a species that is suitable for such an experiment? I would prefer a species the seeds of which germinate relatively quickly under not very difficult conditions.

where have you tried looking for the answer to this question?

It turns out that your research question about halophytes has been asked many times before. You should learn from your predecessors...
Seed germination in halophytes displays a high degree of inter- and intra-specific variability. However, Khan & Gul (2006) report that germination patterns respond to a number of environmental factors (including temperature, NaCl concentration, and presence of different regulating chemicals).

Their paper has over 100 citations, many of which cite germination studies of numerous halophyte species. I'd recommend you start your search there.

You'd also probably benefit by perusing the sources in Ungar (1978) and Panuccio et al. (2014).

Citations

Khan, M.A. & B. Gul. 2006. Halophyte Seed Germination. In Halophyte Utilization and Regional Sustainable Development of Agriculture. pp.11-30
Panuccio, M.R., S.E. Jacobsen, S.S. Akhtar and  A. Muscolo. 2014. Effect of saline water on seed germination and early seedling growth of the halophyte quinoa. AoB PLANTS 6: plu047
Ungar, I.A. 1978. Halophyte Seed Germination. Botanical Review 44(2): 233-264

Thank you for your helpful post, it was exactly what I was looking for.


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What is the diet preference of American cockroaches?
I found a research article1 on the diet preference of German cockroaches. It reveals that those cockroaches prefer to eat bananas most. I wonder if it is the same for American cockroaches. And also, can American cockroaches survive on wood and water alone?
 1. El-Sharabasy, H.M., Mahmoud, M.F., El-Bahrawy, A.F., El-Badry, Y.S. and El-Kady, G.A., 2014. Food preference of the German cockroach, Blattella germanica (L.)(Dictyoptera: Blattellidae). Cercetări Agronomice în Moldova, 2(158), pp.81-88.

Bananas? In Germany? Bananas!

American cockroaches (Periplaneta americana) are omnivorous and opportunistic feeders, and as a result, they eat a large variety of foods. They will eat almost anything.
Favorite foods: They are particularly fond of fermenting foods$^{4,6}$ and also prefer sweets$^2$.
Common foods they eat: plant materials, dead animals, sugar, oil, cheese, beer, tea, soap, leather, bakery products, paper, starch in book bindings, manuscripts, glue, hair, flakes of dried skin, soiled clothing, glossy paper with starch sizing and generally most human or pet moist food or other organic matter $^{1,3,5}$. They have also been observed feeding on dead or wounded cockroaches of their own or other species as well as their own cast-off skins and egg-capsules$^6$.
 According to EOL:

 Some of [their food] items, such as cellulose, can not be digested by normal means. However, like cows and other grazing animals, cockroaches have a symbiotic relationship with a bacteria that allows them to digest such substances.

As a result, they could almost certainly survive on just wood and water.

Citations:
 {1}  Bell, William J. and K.G. Adiyodi. (1981). American Cockroach. Springer. pp. 1, 4. ISBN 978-0-412-16140-7.
 {2} Barbara, K. A. 2014. American cockroach. University of Florida Institute of Food and Agricultural Sciences. Retrieved 11 February 2017. http://entnemdept.ufl.edu/creatures/urban/roaches/American_cockroach.htm .
 {3} Jacobs, Steve. "American Cockroaches". The Pennsylvania State University. Retrieved 11 February 2017. http://ento.psu.edu/extension/factsheets/american-cockroaches .
 {4} Jones, Susan C. 2008. Agricultural and Natural Resources Fact Sheet: American Cockroach (HYG-2096-08). Ohio State University. http://ohioline.osu.edu/hyg-fact/2000/pdf/2096.pdf.
 {5} Milne, L. & M. Milne. 1980. National Audubon Society Field Guide to Insects and Spiders. Knopf, New York, NY. p 393. ISBN: 0-394-50763-0.
{6} Periplaneta americana: Palmetto bug. Encylopedia of Life. Retrieved 11 February 2017. http://eol.org/pages/1076920/hierarchy_entries/51102706/details .


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How does the body regenerate nerves?
If neurons come from neuroblasts which come from neuro stem cells that are embryonic, how is it possible for an adult to regenerate nerve tissue? Are neuro stem cells created during later stages of life, and, if so, where? Or is it solely a finite repository of stem cells somewhere?