9
votes
2answers
269 views

Are there differences in DNA between humans of today and humans from 2000 years ago?

Are there any significant differences in our genome compared to the genes of our ancestors from 1000-2000 years ago? And if there are significant differences, do they result in significant ...
9
votes
1answer
127 views

Is there a biophysical causation from local field potential (LFP) to spikes?

Many experiments showed that neurons tend to fire at some phase (usually trough) of local field potential (LFP) oscillations, such as theta or gamma rhythm. LFP is supposedly generated by a population ...
9
votes
3answers
193 views

Does GFAJ-1 use Adenosine triarsenate as its energy currency?

Regarding the bacteria found in Mono Lake, CA that scientists believe uses or can use arsenic in its DNA backbone where life as we know it uses phosphorus (according to their experiments depriving the ...
12
votes
3answers
175 views

Why do some fruits have a much wider range of acceptable sizes than others?

Some fruits such as pumpkins can grow to be 100 lbs. Under different conditions, the same variety of pumpkin can produce a 15 lb. fruit. Both plants are healthy, and look the same except for their ...
12
votes
1answer
211 views

Why do people dying of immune deficiency diseases appear sick?

Please forgive the obviously silly appearance of this question, and/or of the tenor which may come across as flippant or dismissive of real world suffering. My intention is none of the above. As a ...
4
votes
1answer
93 views

Are CN3, CN7, CN9 and CN10 the only Parasymphatetic Cranial Nerves?

It has been my thought for a long time that that is the case but I am unsure about it now, since the parasympathetic tract of colon sigmoideum does not seem to have connection with CN 10. It connects ...
8
votes
2answers
171 views

Electricity generated by the body and its applications?

I recently came across this article from Nature. In it, it states that the snails have "tiny biofuel cells that extract electrical power from the glucose and oxygen in the snail’s blood", and that the ...
1
vote
1answer
87 views

Does the Parasympathetic Tract of Colon Sigmoideum Travel with Nervus Vagus and its Nucleus Dorsalis Nervi Vagi?

I have the following tractus now: nucleus parasymphaticus sacrales -> nervus splanchnic -> ganglion terminalis -> colon sigmoideum The tract is parasympathetic. It suggests me that it should ...
9
votes
1answer
228 views

How are there alternative initiation codons?

According to wikipedia and the original complete sequence of the K-12 genome, there are multiple non-AUG start codons such as GUG and UUG. How is this possible? I'm particularly curious about the ...
6
votes
1answer
239 views

Effect of histidine on the binding affinity of HisP

I was asked the following question by my teacher: A gene regulatory protein called HisP regulates the enzymes for histidine biosynthesis in the bacterium E. Coli. HisP is a protein whoes ...
12
votes
1answer
309 views

Quantum mechanics in biology

There is a growing interest in the applications of non-equilibrium quantum dynamics to describe biological processes (I'm not talking here about Penrose's old theories, but new stuff -- quantum ...
8
votes
3answers
217 views

Spatial resolutions in optical microscopy

I have read that different optical imaging techniques such as such as wide-field microscopy, confocal microscopy or STED microscopy can theoretically achieve a different spatial resolution. ...
6
votes
1answer
195 views

Effect of spaying on the female cat organism and health

Veterinarians often recommend spaying a female cat if the owner does not want her to have kittens. What does biology know about the effect of spaying on female cats' organism and health (apart from ...
7
votes
2answers
473 views

How do we know the brain flips images projected on the retina back around?

Why do we turn images upside down again rather than dealing with them directly, still vertically rotated after passing through our lens? I don't see how that would cause any problems, and how we'd ...
4
votes
3answers
141 views

Robotic surgery for treating cancer?

We can localise cancer cells in the body. We can manufacture materials thin and hard enough to penetrate the body without harming it. So what stops us from creating an automated surgery where the ...
7
votes
2answers
547 views

How does Iota-Carrageenan achieve an antiviral effect?

"Cold Defence" nasal sprays are recommended to be taken either preventatively or in the early stages of a cold. The active ingredient in these sprays is Carrageenan. After some research, the active ...
4
votes
1answer
38 views

How do fibers control muscles?

My professor says Nervus troclearis IV somatomotor fibers supply musculus obliquus superior. and similarly for nervus oculomotorius III Nervus oculomotorius postganglionic fibers supply ...
8
votes
1answer
1k views

Effects of beer on muscle recovery after exercise

I noticed it several times that when I drink beer (even one bottle) after some heavy workout, the next day my muscles are more stiff than other times, and not the same way... Is it because that ...
5
votes
1answer
63 views

Somatosensory System

I have a test in my upcoming Neuroscience class, one of the items on the study guide is: Identify 2 means by which a maintained, constant stimulus produces only a transient excitation of the ...
9
votes
3answers
1k views

Species with reproduction barriers that can both reproduce with a third species

To start with, I do not have a sound knowledge in biology or any formal education in the area. I was told that one of the definition of a species is a reproductive barrier, which means that if two ...
6
votes
1answer
189 views

Brain + ethanol experiment suggestions needed

I need to demonstrate the effects of ethanol on a human brain (or other brain with developed telencephalon) in vitro; ideally the effects on vigilance and/or memory. Could you please suggest such an ...
11
votes
1answer
662 views

Alternatives to TBE buffer for denaturing polyacrylamide gel electrophoresis of DNA and RNA?

I just stumbled upon an article promoting 10 mM sodium borate as an alternative to the well-known TAE and TBE buffers for agarose gel electrophoresis of DNA (Brody & Kern, 2004). They claim that ...
6
votes
2answers
629 views

For how long and how cold should I perform ethanol/isopropanol precipitations of RNA or DNA?

Precipitating nucleic acids using either isopropanol or ethanol is a very common operation, and I've read some very different protocols on the duration and temperature the precipitation should be ...
6
votes
1answer
532 views

Do immature fruits perform photosynthesis?

Most immature fruits are green: peppers, pine cones, plums, lots of them. I want to know if the green is from chlorophyll in the cells. Do the fruit cells perform photosynthesis? When you cover a ...
10
votes
2answers
3k views

What is the advantage of using starter cultures for growing bacteria?

Many DNA isolation and protein expression protocols contain instructions to use a starter culture of E. coli that is then used to inoculate the main culture. What are the advantages of using starter ...
10
votes
3answers
777 views

Why do people say that trans fatty acids are bad for your health?

I've heard from several sources that trans FAs are bad for you and their consumption will lead to cardiac problems, and that they are indigestible. But I also learned from biochemistry that they are ...
6
votes
1answer
1k views

Why does the T7 RNA Polymerase require a reducing environment ie. DTT

Every bloody protocol suggests adding in DTT when doing in vitro RNA transcription. Why? The rationale seems to be that the cytoplasm traditionally has a reducing environment but as the only protein ...
12
votes
3answers
455 views

Why is there a difference in the rotation of the tail fin in fish compared to marine mammals?

I've been thinking about this one, but I can't seem to find what causes this difference. All fishes that I've seen have their tail fin positioned vertical: But all the marine mammals I know have ...
5
votes
2answers
136 views

Difference between biological control and introducing species for conservation?

I have a biology assignment and we have to explain various methods and strategies for conservation, two of which are: Biological control Introduced Species What is the difference between ...
5
votes
2answers
93 views

Synthetic biology using existing cells

I was watching the video at this link: http://www.bbc.co.uk/news/science-environment-17436365 The speaker says that a cell is taken and its original DNA content is stripped out and replaced with ...
9
votes
3answers
915 views

Do men have more extreme variations than women?

This question was considered unsuitable for Skeptics and I think it is more suited to BIology than Cognitive Sciences I was reading this article which I found interesting. It is not supported with ...
3
votes
0answers
132 views

Why are trichomes important for both the roots and shoots of plants?

In what ways are trichomes vital to the plant? Why have them on the plant shoots as well?
14
votes
3answers
791 views

What causes a 'stuffy' or 'runny' nose when you have a cold?

When humans get the common cold, a common symptom is a stuffy or runny nose. Is that the body's immune response or is that the virus's doing?
9
votes
2answers
15k views

Why is SOC medium recommended for transformations?

In pretty much every transformation protocol I've seen SOC medium is used to grow the bacteria for a short while after the tranformation and before plating. I've usually substituted LB medium for ...
9
votes
1answer
547 views

What is a inhibitory tone when talking about neurons?

In this SE answer: Could an "overactive" brain increase the chances of Alzheimer's Disease? user @nico used the word inhibitory tone What does that ...
2
votes
1answer
432 views

Is Aspergillus clavatus an unicellular organism?

I could not find the piece of information form Burton Human Parasitology -book and not by Google. Yeast is divided to two phylums: one of them is Ascomycota. Aspergillus clavatus belong to the given ...
9
votes
2answers
314 views

How can I pare down a PDB file in Python to only include specific residues?

I'm trying to make a script that will take a MTZ file (reflections), convert it into a CCP4 map, then pare that map down to only encompass a desired area to cut down on the size of my PyMol session ...
12
votes
2answers
446 views

Is the 'fluttering feeling' when under stress neurological or physical?

I'm sure that everyone is familiar with the sensation commonly known as "butterflies in the stomach". It is commonly experienced during periods of anxiety or stress (e.g. before high stakes job ...
7
votes
2answers
873 views

Why are goosebumps so ineffective at keeping us warm?

If the purpose of "goosebumps" is to keep us warm, why is it so ineffective? Or are the changes subtle, but important?
8
votes
2answers
334 views

Where do the bacteria within the vagina originate from?

I understand that it's feasible the bacteria within the gastrointestinal tract originate from the food we eat and air we breath, but where does this population of microbes originate from?
10
votes
1answer
579 views

Why is the 3'UTR region highly methylated in most of the human genes?

Most of the human genes are found to be highly methylated in their 3'UTR region (0.8-0.9%). I was wondering if there is any specific reason for this?
3
votes
1answer
513 views

What are all possible vectors for unicellular human parasites?

I got the given question. They want the following pieces of information about protozoological human parasites: disease - parasite - vector. There are 10 proteogenic diseases at the Wikipedia. I ...
6
votes
1answer
117 views

On which date did the official name change of Lactobacillus sanfranciscensis change?

When did the change of official name from Lactobacillus sanfrancisco to Lactobacillus sanfranciscensis happen? An answer ((to the exact day OR within a few days) AND the name of the conference at ...
7
votes
1answer
792 views

How to clone and sequence a gene transcript of unknown sequence?

How might I go about amplifying a gene transcript (mRNA) from animal tissue of which little is known about the genome? In some applications, I have used reverse transcriptase PCR to amplify all mRNA ...
7
votes
1answer
117 views

Does the MS2 RNA binding protein have any translational repression effects?

Reposted from Quora: http://www.quora.com/Does-the-MS2-RNA-binding-protein-have-any-translational-repression-effects I'm thinking of the MS2 protein binding to its RNA hairpin target. Would the ...
4
votes
0answers
80 views

What is the distance between the 3' 18s rRNA (the Kozak consensus sequence) and the A-site of eukaryotic ribosomes during protein translation?

Reposted from Quora http://www.quora.com/What-is-the-distance-between-the-3-18s-rRNA-the-Kozak-consensus-sequence-and-the-A-site-of-eukaryotic-ribosomes-during-protein-translation The Kozak sequence ...
7
votes
1answer
7k views

What is the difference between “dikaryotic” and “heterokaryotic” states in the sexual lifecyles of fungi?

Many fungi undergo a reproductive phase in which more than one genetically distinct nuclei (from 2 separate mating types) is present within the same cytoplasm. In the Ascomycota and Basidiomycota, ...
10
votes
1answer
103 views

To which distinctions does the term “hymenoptera” refer?

Hymenoptera is an order of insects that includes bees, ants, and wasps. A quick search gives the following etymological analysis of the term hymenoptera. hymen (membrane) + pteron (wing) Does ...
12
votes
1answer
3k views

Why does Penicillin only affect bacterial cell walls

I was quite fascinated by the feature Should Science Pull the Trigger on Antiviral Drugs—That Can Blast the Common Cold? in this month's Wired magazine. They explain that Penicillin is effective at ...
13
votes
5answers
6k views

Origin, or source, of rhesus negative in human blood

This is my first post here, so please be gentle. I recently learned that I have Rh- blood (I'm A-), and was idly looking into blood types on Wikipedia. I was surprised to find that relatively few ...

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