r/askscience

What I am wondering is what is the mechanism of fentanyl or carfentanil killing someone, how it is so concentrated, why it is attractive as a recreational drug and is there anything more deadly?

And any other deases that kills the host fast?

Maybe my understanding is wrong but I seem to be able to safely eat say lettuce of cabbage “raw” despite having the same exposure to birds as wheat, so what makes “raw flour” dangerous?

Could you destroy the nucleic acid with UV or microwave radiation, while preserving the capsid?

Is there any science behind an herbivore unintentionally consuming things outside of plant material?

I remember watching Grady's practical engineering videos about dams, and how the water has a potential difference and may erode a dam from underneath.

Remembering the science headline about beavers getting stressed by running water, do we know if this underground water flow also stresses them, and causes them do try to plug up the pathway?

For example, monarch butterflies and viceroy butterflies. Monarchs are the toxic ones animals know not to eat, but viceroys are not (I think). If the monarchs go extinct as they're threatened to, how long before the viceroys mimicry is no longer effective?

I.e are they still considered the same species or have they been separated long enough that are two different species?

I’ve read about plant “cancer” but in my research I haven’t found much about fungi cancer. Does it happen ? Through what mechanics? How might it look like ?

If most of the various prion diseases out there affect the same PrP protein, why are there different diseases?

For example in fatal familial insomnia the main initial symptom is the namesake insomnia, but CJD is usually memory problems and behavioral changes, and similar differences for other prion diseases. I understand that the end-state is usually fairly similar, with all of them causing issues in the central nervous system and eventually death, but I'm curious about why they present differently in the beginning.

Is it because of different parts of PrP misfolding causes different symptoms? Or do they affect different parts of the nervous system? Or is it something else entirely?

And do all prion diseases come from PrP or are there other proteins that misfold and become prions, just more rarely?

Surely genes for sexual reproduction would be less successful, as it is generally slower, requires mates, and has a larger chance of infertility occurring, causing them to be selected against? Also, surely a gene causing either a return to asexual reproduction, or simply biasing the fertilisation process, would be successful, as more offspring would have that generally than would not, so would spread, preventing sexual reproduction?

Tortoiseshell cats have a different melanin allele on each X chromosome. Why do we see what appear to be lines or patterns of fur coloration?

One X chromosome is inactivated by Lyonization and becomes a Barr Body, the other is expressed. The expressed melanin allele determines the color of the fur produced by the cell.

When a somatic cell divides, the daughter cells express the same activated X, and suppress the same X in the Barr Body, so the color of the fur of daughter cells is the same its parent cell.

So we shouldn't expect to see a coat where the fur colors are expressed uniformly at random from the set of two possible alleles.

We should expect contiguous "islands" of coloration, from all spacially adjacent descendent cells divided from the earliest progenitor cells, which progenitors selected an X at random to supress.

So finally the question: But why do we also see what appear to be lines or patterns?

Differential growth rates of the descendent somatic cells? Die offs of certain cell lineages? Is this mostly determined in utero or can it change over the lifetime of the animal?

It’s my understanding that in something like a calico cat the X inactivation is random and therefore a calico cat clone would have a different pattern. That’s not at all how brindle coats work in dogs (since you know brindle males are common) so I’m curious.

Many people say "oh the poor tree, don't cut it down" even though it was planted for commercial use. So is there any correlation from the amount of CO2 a tree takes in to its age? Like at age x, the tree takes in y kg of CO2 per month or something like that. And if there is, can somebody point me in the right direction for a study or something like that?

Why hasn't one sex increased/decreased significantly over another?

When observing flies, especially the common housefly, they seem to never fly in a straight line from A to B but they always have this unpredictable fly pattern (that also makes them hard to catch). Why is that? Is that some kind of evolutionary defence mechanism that makes them harder to catch? Is it because of their vision/perception of space? Is their flight so unstable they literally can’t go straight?

I don't understand how point mutations are possible. How can only a single nucleotide in a DNA-sequence change, if A can only pair with T and G can only pair with C? If there is a sequence "ATGCTACG" and the first C changes to T, then wtf :D

In the ABO blood group classification, it is the type of sugar that is produced by an enzyme in the bodies of individuals with those blood types determines their blood type. This enzyme produces sugar, but for what reason? Does the sugar produced become available for use within muscles or something? These sugars are the antigens that are the defining characteristics of the different blood types, so to say they can be consumed by the muscles would seem strange as that would mean that at some point those blood cells turn to O (once rinsed of their antigen by the muscle), so I'm assuming the production of these sugars is not for the purpose of fuelling the muscles. What is the specific purpose of the production of these sugars?

People can tell where a sensation is (arm vs leg vs back vs foot).

These signals travel to the spinal cord and to the brain.

How do these signals carry the location information of a sensation? For instance, is the signal that results from an electric shock to the arm different than the signal from an electric shock to the foot?

Additionally, there are a lot of other information carried to the brain as well such as pressure, texture , etc.

Is this something science has figured out? Are there any current attempts to use ML to decode nerve signals?

If nerve signals are ever decoded, then the potential is massive. You can build devices that replicate sensations of certain things.

I've had about a dozen cicadas land on me and refuse to leave until I physically grab them and pull them off. They're splattered all over my driveway because they land there and don't move as cars run them over.

How does this species not get absolutely picked apart by predators? Or do they and there's just enough of them that it doesn't matter?