Most Popular
1500 questions
12
votes
1 answer
Why does getting certain chemicals in cuts hurt?
More specifically, shampoo. What are the mechanics of detecting a noxious chemical stimulus in terms of which receptors recognise what, how do they do it, and how is this information relayed to the nerve cells?
Why is the pain (and so signal, I…
Meow
- 667
- 5
- 11
12
votes
1 answer
Why do birches have a white bark?
Several species of the tree genres Betula have a white bark,especially when they are young. This is quite peculiar to trees - at least in central Europe; so I'm wondering if there is a ecological reason behind it.
The first idea I have is that they…
and-bri
- 282
- 2
- 10
12
votes
2 answers
Online phylogenetic tree of human lineages
I am looking for a source of information about the diversity of human lineages and their relationships.
With a quick google search it is easy to find this type of tree
A perfect online resource would...
Contain a lot of lineages going to the most…
Remi.b
- 68,088
- 11
- 141
- 234
12
votes
4 answers
Is nicotine toxic to humans?
More specifically, is nicotine in the concentrations that smokers receive when smoking cigarettes toxic? I know that in great enough concentrations it can be toxic (but then, so can just about anything else, including oxygen) and I know that in…
terdon
- 12,803
- 5
- 46
- 73
12
votes
1 answer
Which is the reference 16S rRNA?
Recently, I've stumbled upon a fact, which hasn't bothered me for many years. The fact is that all universal 16S primers are written as "[FR][0-9]+" (in regex notation), that is they have a position with respect to a reference. I've read through…
Eli Korvigo
- 1,007
- 6
- 15
12
votes
1 answer
Has the acronym DNA ever been widely understood to stand for deoxyribose nucleic acid?
I have a friend familiar with evolutionary biology who was recently bragging about how much he knows. I asked him what DNA stood for, and he answered it stood for 'deoxyribose nucleic acid'. When I claimed it stood for deoxyribonucleic acid, he…
MordantHubris
- 123
- 5
12
votes
2 answers
Are there viruses that affect cells across different species?
I'm not a professional in biology nor a student, but I'm curious about this. To be more specific: why doesn't a plant virus affect animal cells?
I suspect that different kinds of cells have different ways to replicate DNA and that this is the reason…
leo
- 223
- 1
- 5
12
votes
0 answers
Anatomical Angle Made by the Fingers of an Extended Palm
Does the angle made by the fingers (excluding the thumb) of an extended palm (as shown in the figure below) have a name (such as the Lovibond or Cobb angle, for instance) ?
I have already checked Modeling the Constraints of Human Hand Motion,…
Lucian
- 229
- 2
- 5
12
votes
1 answer
What is the half-life of dNTPs at 95 °C?
I'm looking for the half-life of dNTPs, either as a whole or broken into individual bases, at 95 °C (or similar). A titration would be great if that exists. I can provide more specifics if need be, but broadly the idea would be 'able to polymerize'…
metaditch
- 121
- 4
12
votes
2 answers
What hair do aquatic mammals have?
I'm reading an essay on the creating of the Mammalia zoological classification (Londa Schiebinger, The American Historical Review, Vol. 98, No. 2 (Apr., 1993), pp. 382-411).
It contains the statement (page 386)
All mammals (including the whale)…
Canageek
- 275
- 1
- 3
- 9
12
votes
4 answers
How do antibiotics combined with a non-Western diet affect weight loss?
Wikipedia describes a Western diet as:
... higher intakes of red and processed meat, butter, high-fat dairy products, eggs, refined grains, white potatoes, french fries, and high-sugar drinks.
In the following article there is information about…
Ein Doofus
- 293
- 1
- 4
12
votes
1 answer
How does the stem-loop cause intrinsic transcription termination?
In this animation, towards the end (about three quarters) the process of transcription termination is shown. It states that the transcribed RNA forms a hairpin loop (or stem-loop), which halts the transcription process.
My question is, why does it…
arik-so
- 223
- 2
- 5
12
votes
2 answers
Why is the microbial ecosystem of the gut so susceptible to disruption by pathogens?
From all accounts, it seems as if the Escherichia, Enterobacter, etc. that live and thrive in the human gut are pretty well entrenched. I know that these microbial populations are often analyzed as an ecosystem.
What surprises me is that it seems…
jonsca
- 4,761
- 3
- 31
- 58
12
votes
1 answer
What really is color and how do we perceive it?
How do our brains actually transform the information that the cones in our eyes receive into the different colors that we can see and imagine?
mateos
- 251
- 1
- 8
12
votes
1 answer
Why is chlorophyll green? Isn't there a more energetically favorable color?
Chlorophyll being green means it absorbs light in the red and blue area of the spectrum. Isn't this the high and low energy light? Wouldn't plants get more energy if they absorbed light in the green area of the spectrum instead of the red one?
Sarah Toufiq
- 121
- 1
- 4