7
votes
2answers
489 views

Which phylum appeared most recently

I'm aware that our earliest records of many major animal and plant phyla come from the Cambrian or Precambrian periods, and I'm also vaguely aware of some of the objections raised with general concept ...
4
votes
1answer
37 views

Are common eye defects inherited?

If one parent is nearsighted and the other is farsighted. One parent developed nearsightedness later in life, while the other was born farsighted and they are both the first ones in their family to ...
1
vote
2answers
59 views

Maintaining purebred pedigrees and how to lessen chance of getting disease?

Many breeds of dogs are known for a high incidence of genetic disorders. German shepherd and Saint Bernard dogs are predisposed to developing a crippling condition called hip dysplasia. Q: What ...
0
votes
1answer
39 views

To what extent is it possible to understand if a bacteria can produce a protein? (in silico only!)

I have to answer a question about a sub-task of my thesis: Can the bacteria X produce the protein Y? I searched of course Google and BLAST. There is no data supporting that this specific bacteria ...
4
votes
4answers
103 views

E-value BLAST cut-off

What is the best cut-off for e-value in BLAST? Some say 0.01 ,others 0.0001? Even BLAST tutorials don't give a very clear idea about which cutoff suits which purpose? Could some experts give me a ...
0
votes
0answers
17 views

coevolution by physical interaction between RNA sequences

There are several items that relate to the concerted evolution between pairs of sencuencias (especially structural) rRNA as a consequence of physical interaction in tertiary, or even quaternary ...
1
vote
0answers
16 views

detection of primary origin (natural selection or genetic drift) on alterations in sequences

I recently had a question about how to distinguish the origin of variations in the sequences of rRNA as to whether alterations are generated by genetic drift or natural selection. For me it has not ...
5
votes
1answer
123 views

A question about the intersection of evolution and thermodynamics

From this 2014 article in Quanta magazine by Natalie Wolchover there is a quote from a physicist with an intriguing idea about evolution: “You start with a random clump of atoms, and if you shine ...
2
votes
1answer
502 views

Lyonization and X-linked disorders?

Lyonization or X-chromosome inactivation is the conversion of all but one, X-chromosomes in Females into non-coding heterochromatin (i.e. deactivated) leading to the formation of one or more Barr ...
3
votes
1answer
38 views

Equation for accurate prediction of PCR yield

It is a cliche of freshman biology labs to point out that "every cycle of PCR doubles the DNA, so the yield will be $2^{cycles}$ times the template amount". However, if this were true, 1 ng of ...
3
votes
1answer
27 views

Regarding apoptosis and inhibitors

If there is an apoptosis shut-off mechanism of any kind, one could call it a null-apoptosis mechanism. If this is possible, could there be a null-apoptosis inhibitor? Something that inhibits an ...
31
votes
4answers
13k views

Death because of distilled water consumption

One of my friends said that I would die if I drank distilled water (we were using it in a chemistry experiment) I gave it a go and surprisingly did not die. I did a bit of Googling and found this ...
-1
votes
1answer
67 views

What is the outcome of a human population starting with only 2 individuals? [closed]

Starting with a human population N = 2, is there any way the genetic variability seen today could have come about? I don't know that much about meiosis, but isn't there a very limited number of ...
2
votes
1answer
25 views

Regarding signalling pathways

Do all signalling pathways have something that can inhibit them? If the signal pathway is benefitial and it is inhibited would the inhibitor be caused by a biological problem? Are all inhibitors ...
4
votes
3answers
188 views

Are humans the only animal that requires “clean water”?

I've seen a number of animals - dogs, cats, squirrels, ducks and geese, etc drink from puddles, some of them were muddy, others had green flora growing under water. Same goes for lakes and rivers. A ...
4
votes
2answers
377 views

Does making yogurt from non-pasteurized milk work against possible disease bacteria?

In the past, when there was no pasteurization, could making yogurt from milk lower the chance of getting infected by bovine tuberculosis (or other diseases from infected milk)? For example, would ...
13
votes
2answers
2k views

How many organisms have ever lived on Earth?

I've looked for some information on this, but couldn't find anything useful. Has there been any noteworthy attempt to estimate the sum amount of individuals of all species that have ever lived on ...
7
votes
1answer
408 views

Perspiration after drinking water

If we don't drink water for a long period of time(say,10 hours), as during fasting and then when we break our fast by drinking water why is it that our body starts sweating?
2
votes
2answers
64 views

Is it theoretically possible to treat filaggrin deficiency with a dietary supplement?

http://f1000.com/prime/reports/m/3/2/ "Filaggrin is a highly abundant protein expressed in the uppermost part of the epidermis that is critical to the formation and hydration of the stratum ...
0
votes
1answer
59 views

Prokaryotic Ribosomes

During bacterial protein synthesis, when ribosomes attach to the cytoplasmic membrane and form a polysome, to what molecule are the ribosomes attaching? Is the polysome held to the cytoplasmic ...
15
votes
3answers
394 views

Why do some trees have a life span, while some don't?

I have heard that there is no limit on the growth of trees, but then why do some trees, such as boxelders and poplars, tend to live shorter than redwoods, for example? Some advertisements for improved ...
2
votes
3answers
61 views

Can 'hardware' thermalization explain memory decay?

Often we are able to memorize very precise bits of information (exact addresses, birthdays of inlaws, number of dirty socks under the bed), but over time our recollection tends to become fuzzy. We no ...
1
vote
1answer
41 views

About the quality of microsatellites

I built a script to detect microsatellites in a FASTA file. However, there are thousands of possibilities. So, my question is: what are the markers of a "good" or "useful" microsatellite? - How ...
0
votes
0answers
17 views

Book recommendation on mammal (or just primate) behaviour, especially in relation to child-rearing

I have a growing frustration with the lows 'new-age' parenting is reaching, along with asininity of so much of our public schools' (and summer camps') philosophies and policies in relation to our ...
3
votes
1answer
259 views

Is there any size limit to the amount of information a human (or other) brain can hold

Im not sure how this would ever be tested but is there a limit to how much the brain can 'hold' before it reaches capacity ? I guess this could also be interpreted in terms of memory, as how well ...
0
votes
1answer
28 views

Is there a correlation between total neurons and intelligence?

Thanks for looking. First off, I am not a biologist, just a curious layman, so I apologize in advance if this isn't a "good" question. Please don't downvote me into oblivion. I read today that the ...
2
votes
1answer
68 views

The mechanism of mechanoreception?

I am interested in knowing the molecular mechanism behind mechanoreception/mechanotransduction (i.e. mechanism behind receptor potential generation on mechanical stimulation). I know that most ...
2
votes
1answer
22 views

Currency metabolites vs. current metabolites: What's the right term?

I have seen the two terms currency metabolite and current metabolite used interchangeably. Is there a consensus on which is the ...
2
votes
2answers
49 views

which signalling pathway is involved in cancer?

Columnar epithelial cells from the colonic mucosa are studied to identify abnormalities in cell signaling pathways. Abnormal epithelial cells from colonic adenocarcinoma are shown to have a mutation ...
1
vote
0answers
110 views

How does a TOPflash/FOPflash assay work to detect beta-catenin protein expression?

I am reading an article (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3596711/) wherein a TOPflash/FOPflash assay is used to detect beta-catenin protein levels in a COS-7 cell line. I can't find a good ...
7
votes
2answers
226 views

Why does Hunger lead to the aggressive behavior?

I have observed that frequently when people are hungry; they tend to get angry more easily on pointless issues. Does this mean that our fight or flight response is more active when a person is hungry? ...
7
votes
1answer
326 views

Yellow/Orange Fungus on Oak Tree

What is the fungus pictured below? The photo was taken October 6, 2013 near San Antonio, TX. I have Googled it and my results suggest Laetiporus root rot (Laetiporus sulfureus). According to this ...
7
votes
2answers
110 views

How do ants sense imminent rainfall?

I have always been told to watch to see if ant-hole mounds are built up as a sign of imminent rainfall. My questions are, if what I have always been told is true, then by what mechanism do ants ...
6
votes
0answers
120 views

Birds placing sticks on train tracks?

I live in a semi-rural area in Germany, close to a park which trains go through every 20 minutes. Today, I saw something that left me perplexed. There is a large population of birds that look like ...
4
votes
2answers
5k views

Does sour food cause sweating?

While eating sour food or candy, I start to sweat if it's sour enough. My body feels much hotter although my actual temperature is the same, my forehead starts sweating a lot and I feel like it just ...
5
votes
1answer
93 views

Are there any cases of observed extreme speciation [closed]

Is there an observed (direct not indirect) speciation on record showing a species shift within the span of history of recorded science?
3
votes
0answers
45 views

Why does pasta really boil over? [migrated]

I was making pasta, and I noticed the pasta boiling over. I thought about it some more, and I realized I had no idea why this was happening. When the lid is on, the foam rises. When the lid is off, ...
10
votes
4answers
3k views

What nutrients can humans absorb in the mouth?

For instance, I realise being able to absorb simple sugars in the mouth is pivotal in the rapid action of oral glucose gel. Thus I was wondering what nutrients in general can be absorbed directly ...
1
vote
1answer
40 views

psychological database with sequenced DNA records

I'm looking for an epigenetic database which includes for each example the psychological history of the persons DNA. Right now I can only find DNA and epigenetic databases. Sadly none of the databases ...
1
vote
1answer
16 views

Question regarding 2 constructs of tobacco plant

Six independent transformation experiments of tobacco leaf explants were carried out using two different constructs - (1) construct I containing only a Hygromycin-resistance gene $(HYG^R)$ as a ...
2
votes
2answers
73 views

Ni-NTA purification, problem with the chaperone protein

I'm trying to purify the protein by Ni-NTA affinity chromatography. It seems that my protein (size about 54 kDa) is co-purified with chaperone protein (probably GroEL - as the band is around 57kDa). ...
3
votes
1answer
59 views

Getting xyz co-ordinates from a .map file (CCP4 format) in VMD

I have a .map file which contains x-ray crystallography data of a bacteriophage. The format of the file is CCP4. I can open the file using VMD. However, I am unable to get the xyz co-ordinates. It ...
1
vote
1answer
19 views

Formation of peptide bond..?

Proteins peptide bond is made by condensation process in which a molecule of water is released and according to this process it is not favorable in water systems than how peptide bond is formed by ...
2
votes
1answer
58 views

Is there any research paper state the pros and cons for human to be taller?

Is there any research paper state the physical health pros and physical health cons for humans to be taller? For example, shorter people seems to more likely to get involved in heart diseases and ...
2
votes
2answers
40 views

TB disease - treatment and infection

Background: I'm currently performing research in mathematical biology, specifically on the treatment dynamics of HIV and TB co-infection. Question: Can a person infected with TB disease, who are ...
2
votes
1answer
139 views

Why are men stronger than women?

What are the evolutionary explanations for why women are weaker than men (on average), and is this difference adaptive? I suppose that something puts pressure on men to be stronger than women, but I ...
3
votes
1answer
105 views

Optimization of annealing temperature

I am trying to optimize annealing temperature for some primer pairs. I have tried optimization using cDNA, genomic DNA, Taq polymerase, phusion polymerase etc., but every time I am either getting ...
3
votes
1answer
37 views

In the endomembrane system, after a protein leaves the rough ER, where does it go?

It can either go to the smooth ER then to the Golgi or it can go directly to the Golgi, right? Also, the smooth ER gets all of its material to synthesize things from the rough ER, right? Sorry, I ...
2
votes
1answer
16 views

Classify chemotherapy drugs?

I'm studying a TCGA dataset trying to find correlations between gene expression and clinical data which might shed light on some pathways. One column of the clinical data provides a list of ...
7
votes
2answers
955 views

Why do humans find baby animals cute?

Why do humans find baby animals like cats, dogs, ... so cute? As these are potential competitors or even natural enemies (like e.g. tigers, leopards, ..), the protection instinct (reasonable for the ...

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