All Questions
17
votes
2answers
212 views
How do fairy rings propagate?
It was somewhat new to me that mushrooms usually aren't individual organisms, but are merely the visible bodies of a bunch of fungi living in the soil. I know that mushrooms emit spores to reproduce, ...
17
votes
3answers
138 views
How crowded is the bacterial cell?
I was wondering what is the protein concentration in an E. coli cell. When studying enzyme kinetics and activity in vitro, I would argue that the substrate and enzyme concentrations resemble those in ...
17
votes
2answers
1k views
Do gene expression levels necessarily correspond to levels of protein activation?
I have seen a lot of research into molecular mechanisms of diseases/phenotypes use measures of RNA as a 'proxy' for the level of protein available in the cell. Is this actually valid?
My problem ...
17
votes
2answers
910 views
How long do your eyes need to adapt to darkness and reach full contrast?
I heard you should wait some time until your eyes adapt to darkness and are able to see smallest luminosity differences, otherwise you might overlook faint objects in the ocular. Are there any rules ...
17
votes
1answer
197 views
Is there any convincing evidence for the existence of nanobacteria?
The existence of nanometer scale microorganisms has been proposed and used explain several phenomena including morphological structures in a martian meteorite (ALH 84001) and implication in the ...
17
votes
1answer
324 views
How, on a physical level, does ATP confer energy?
When ATP is used as the energy currency to make, say, reaction X + Y → Z happen, is what happens on a physical level down at the molecular scale that during the reaction
ATP + H2O → ADP + Pi ...
17
votes
1answer
5k views
How does cerebrospinal fluid circulate in the central nervous system?
Cerebrospinal fluid (CSF) is produced in the choroid plexus of the lateral ventricles and in the 4th ventricle of the brain. CSF then circulates through the ventricles of the brain and the ...
17
votes
1answer
247 views
Why do ants live so long?
I was surprised to learn that worker ants in some species live many years. I would have expected a lifespan of a few weeks or months (which is apparently the case for many species).
What factors ...
17
votes
2answers
73 views
How is duration of efficacy estimated for vaccines?
Vaccines, especially those given in adulthood, usually have term limits attached, eg: 10 years for yellow fever or 3 years for typhoid. Since presumably the time course of an immune response is no ...
16
votes
4answers
445 views
How to understand influenza strain designations?
What do the strain designations for flu mean?
For example avian flu is classified as H5N1, what do the letters H, ...
16
votes
2answers
240 views
Why would diffusion be faster across a non-specialised tissue?
The standard protocol for a person experiencing chest pains is to chew a 300mg aspirin tablet, the argument being that chewing rather than swallowing the tablet results in the aspirin entering the ...
16
votes
2answers
396 views
Can rats pass on memories of a maze to their offspring?
A friend of mine told me once about a documentary movie he saw some years ago. On this movie he saw scientists talking about particular experiment. This experiment involved rats and probably ...
16
votes
3answers
318 views
How does the immune system “learn” from a vaccine?
According to Wikipedia:
A vaccine typically contains an agent that resembles a disease-causing
microorganism, and is often made from weakened or killed forms of the
microbe, its toxins or one ...
16
votes
3answers
512 views
Are single-celled organisms capable of learning?
I've read that the amoeba is capable of learning. Since these protists have no nervous system, it's safe to assume that even highly simplified learning mechanisms of the Aplysia are miles off in the ...
16
votes
1answer
393 views
Is kissing a natural human activity?
The word natural here is meant in contrast to it being a sociological construct.
Is kissing in all its forms something natural for humans? Is it instinctively erotic? Or is it just a conventional ...
16
votes
2answers
17k views
What's the maximum and minimum temperature a human can survive?
This is a question that has been in my mind since I was a kid. I'm not a doctor, nor even a biology student, just a curious person. What is the minimum and maximum temperature a human body can stand ...
16
votes
2answers
239 views
Can an adult without genetic lactase persistence still develop a tolerance for dairy foods?
While investigating the rise of adult lactose tolerance, I came across the news that China has been encouraging its citizens to drink more milk, even though most of the Asian population lacks the SNP ...
16
votes
1answer
490 views
Why do stars disappear when I look at them?
I've noticed that when I'm out at night stars seem to vanish when I focus on them. I assume the reason is physiological and not astronomic. Why does this happen? I would expect that things would be ...
16
votes
1answer
427 views
Do insects' muscles become stronger with exercise?
I am curious to know if insect muscles become stronger with exercise, because I have seen many insects get tired out, but I have never seen one get stronger. They always seem to become permanently ...
16
votes
3answers
210 views
How is the blood volume of a living organism measured without killing it?
How is the blood-volume of an organism measured without killing it? NOTE: The blood-volume of an organism is defined as the total volume of blood present inside that organism.
16
votes
3answers
141 views
What is the optimal frame size for protein secondary structure prediction methods?
The whole question is
What is the optimal frame size for the second and third generation protein secondary structure prediction methods? Justify your answer.
I remember it has something to do ...
16
votes
1answer
2k views
How does laughing gas (N2O) work?
Laughing gas (N2O), well, makes people laugh.
How does just a gas make us do that, there has to be some hormones at work...
So, I wanted to know how this works? What is the mechanism?
16
votes
1answer
368 views
ATP cost for gene expression
How would you estimate the number of ATPs required to transcribe, export and translate a single eukariotic protein?
16
votes
1answer
1k views
What is the criticality of the ribosome binding site relative to the start codon in prokaryotic translation?
In prokaryotic translation, how critical for efficient translation is the location of the ribosome binding site, relative to the start codon?
Ideally, it is supposed to be -7b away from the start. ...
16
votes
2answers
154 views
What is the reason behind choosing the reporter gene when experimenting on your gene of interest?
I noticed within example experiments in class that different reporter genes are chosen to be inserted near your gene of interest to prove whether or not the gene is being expressed. For example, you ...
16
votes
2answers
2k views
What causes fingerprints to form and why is the pattern formed unique?
I've found research that suggests that the reason we develop fingerprints is because they aid us with feeling surfaces (Scheibert, et al. 2008) and not to increase friction and help with the gripping ...
15
votes
2answers
1k views
How do the brain and nerves create electrical pulses?
I have heard that information is sent between the brain and peripheral nerves via electrical pulses or signals, but I don't understand how they create them in the first place.
15
votes
2answers
703 views
Which organism has the smallest genome length?
Which animal/plant/anything has smallest length genome?
15
votes
4answers
367 views
How do trees manage to grow equally in all directions?
I was walking down a road with these beautifully huge trees when this question occurred to me.
Large trees with many thick branches have to grow equally in all directions, or they would tip over. Is ...
15
votes
3answers
450 views
Is “computational biology” different from “bioinformatics”?
Are "computational biology" and "bioinformatics" simply different terms for the same thing or is there a real difference?
15
votes
5answers
470 views
Online Molecular and Cellular Biology Video Lectures?
I am looking for video lectures to go through to guide my reading in intro molecular and cellular biology. I've had intro bio and I study evolutionary theory, but my molecule- and cell-level knowledge ...
15
votes
3answers
199 views
Is exon order always preserved in splicing?
Are there any cases in which the splicing machinery constructs an mRNA in which the exons are not in the 5' -> 3' genomic order? I'm interested any such cases, whether they involve constitutive or ...
15
votes
2answers
232 views
What are the major evolutionary pressures for Bioluminescence?
What are the major evolutionary pressures for Bioluminescence?
15
votes
2answers
2k views
What is the mechanism behind “acquired” alcohol tolerance?
I can understand natural variation in alcohol dehydrogenase (ADH) in a population leading to variation in rate of inebriation (after controlling for other variables -- e.g., mass, food consumption, ...
15
votes
2answers
224 views
Smallest viable reproducing population
What is the smallest viable reproducing population, such as in a human population. By viable I mean a population which keeps genetic defects low (enough).
A very strongly related question: what is ...
15
votes
4answers
754 views
Why are there exactly four nucleobases in DNA?
Does someone know why DNA is composed of four nucleobases? In particular, is there an explanation for the number? Why four and not two, or eight?
15
votes
3answers
236 views
Defining paper(s) in epigenetics
For someone who is interested in learning about the discovery of epigenetics, which are the foundational defining papers in the area?
15
votes
2answers
400 views
How long can I store extracted RNA?
If I extract RNA from a (leaf tissue) sample using a one-step phenol:chloroform extraction, how long can those samples be stored at -80°C? And how many times can I defrost and refreeze them before ...
14
votes
4answers
1k views
How many genes do we share with our mother?
Somewhere I have read we share more than 99% of our genes with every other other person and 98% of our genes with chimpanzees. What does this mean? Don't we share 50% of our genes with our mother and ...
14
votes
5answers
273 views
Can species back-evolve?
One of the tenets of Darwin's theory is the survival of the fittest, ie adaptation of features that allow a species to adapt better to its surrounding environment. I am wondering that given the right ...
14
votes
6answers
607 views
Could Junk DNA be used as a Turing Machine by nature?
In what ways has DNA been studied to see if there a "programmable" aspect to it?
Has nature produced anything resembling a Turing machine within the cell, perhaps using the "junk DNA" as its code? I ...
14
votes
5answers
389 views
How is evolution possible in contemporary humans?
I would like to know if evolution is continuing to happen in modern humans, assuming things like existence of the nuclear family structure, fidelity to one partner, etc. It seems to me the answer ...
14
votes
2answers
638 views
How and where, in the human brain, are memories stored?
Background
I am a computer programmer who is fascinated by artificial intelligence and artificial neural networks, and I am becoming more curious about how biological neural networks work.
Context ...
14
votes
3answers
792 views
Why are there no wheeled animals?
In physics, "almost everything is already discovered, and all that remains is to fill a few unimportant holes." (See Jolly.) Therefore, on Physics SE, people are veering off into different directions: ...
14
votes
3answers
309 views
Are human fetuses more likely to be male?
Question: From a physiological point of view, when sex is determined in a human fetus, is it equally likely to be male or female?
Studies in this area typically measure age at birth, where the data ...
14
votes
3answers
482 views
Transmission of epigenetic regulation through surrogate mother
I know the basics of epigenetics, but I do not know how epigenetic mechanisms are transmitted from parents to children (or if there is even enough literature to derive a consensus). My question is ...
14
votes
2answers
352 views
Intrinsically disordered proteins as potential drug targets
Intrinsically disordered proteins (IDPs) are a class of proteins that do not adopt a stable secondary or tertiary structure under physiological conditions in vitro, but still have biological ...
14
votes
1answer
6k views
Why is coffee a laxative?
How does caffeine (or any additional agents) act as a laxative when ingested? I'm interested in the metabolic/signaling pathway.
14
votes
1answer
185 views
How fast does the rotor in ATP synthase spin?
I'm sure the exact frequency varies, but does anyone know roughly how many revolutions per minute / second the rotating center part makes?
14
votes
1answer
638 views
Why do we get runny noses in the cold?
The most annoying thing for me about being cold is a runny nose. Is there an advantage to having a runny nose when cold? What does having a runny nose achieve?
