2
votes
1answer
961 views

Do bigger animals have more testosterone?

I was wondering the other day outside, thinking about varieties of species and their aggression levels, etc. I had a theory that since these highly aggressive, powerful, and viciously advantageous ...
3
votes
1answer
57 views

Common Ancestry of ETCs and ATP Synthase complexes

Rickettsiales are widely regarded as the ancestor of eukaryotic mitochondria through endosymbiosis. Cyanobacteria are widely regarded as the ancestor of eukaryotic chloroplasts through endosymbiosis. ...
0
votes
1answer
439 views

Which surfaces contain no epithelial tissues and which epithelial tissues are vascular?

Epithelial tissues are found on all the surfaces of the body; including external surfaces and surfaces of organs etc. Are there any surfaces which do not have epithelial? I have read in my book that ...
0
votes
2answers
87 views

Is the poly(A) tail added while transcription is still underway?

I read in Campbell that ....splicing and poly A tail addition may also occur while transcription is still under way. How can the poly(A) tail be added while transcription is still going on?
1
vote
1answer
2k views

Why is the function of lacA (encoding thiogalactoside transacetylase) not clearly understood?

It's almost half a century since the lac operon was discovered but isn't it weird that the precise role of transacetylase isn't clearly understood ? Here a wikipedia article with a link to a journal ...
7
votes
1answer
4k views

Why is ATP the preferred choice for energy carriers?

Why is ATP the most prevalent form of chemical energy storage and utilization in most cells?
0
votes
1answer
81 views

Are there any enzymes in cytoplasm to help the newly-synthesized polypeptide to form tertiary structure?

Polypeptides made by ribosomes which attach to rER will go into the rER to form the tertiary structure. Those polypeptides made by free ribosomes usually stay in cytoplasm. So are there any enzymes in ...
1
vote
1answer
91 views

Attaching suspension cells to coverslip duing mycoplasma contamination detection

I am planing to screen my cell cultures for mycoplasma contamination using the Hoechst 33258 DNA staining method. This method is suitable for adherent cultures. Is this method suitable for ...
1
vote
1answer
92 views

What in neurons and their connections changes during the process of learning?

I'm not sure if this question belongs more in physics or biology (or maybe even computer science)... but biology seemed to fit more. What changes in the state of our brains when we learn things? ...
3
votes
1answer
955 views

How does blue white screening work in selecting E coli that have taken up a plasmid vector?

The plasmid vector I am referring to is pCR 2.1 - TOPO. I added the vector to the E coli and plated them up onto LB+amp+X-gal plate, then incubated. After incubation the plates had two types of ...
1
vote
0answers
63 views

Why did the yeast rise?

Here are the notes I made for an experiment I was doing (I didn't put it here as it is too long) (please ignore the numbers at the end of the pdf file) The graph looks like this: As you see on ...
2
votes
0answers
51 views

Is an antivenom venomous?

What happens when someone takes an anti-venom for an animal they weren't bit by, either for incorrect identification of the animal they were bit by or if they weren't bit at all? I am looking for the ...
6
votes
2answers
7k views

What is the difference between local and global sequence alignments?

Obviously there are a bunch of different alignment tools out there, and I don't want to get bogged down in the maths behind them as this differs from software version to version. I am aware that ...
2
votes
1answer
36 views

Function of an VEGF inhibitor in the treatment of macular degeneration

I'm working on a short presentation of treatments of macular degeneration for a biomedical optics seminar on macular degeneration. Since I don't have any relevant medical or biological background ...
1
vote
2answers
117 views

Examples of virus originated from a living system

Do you know some examples of virus or a viroid (or a prion) that originated from a known living organism? How does the virus/viroid/prion lives? Does it paratize the organism from which the virus ...
2
votes
1answer
460 views

Why were dinosaurs not as smart as we are?

According to http://en.wikipedia.org/wiki/Dinosaur, Dinosaurs were the dominant terrestrial vertebrates for 135 million years. They had a lot of time to evolve. My question is: why were dinosaurs not ...
1
vote
1answer
61 views

How does ultraviolet light influence the decay process of wood?

Given a piece of wood, how does putting it in the sun or not influence the rate of decay due to rot (assuming that it's in an otherwise humid environment)?
3
votes
2answers
90 views

Humidity for wood rotting

If I put a piece of wood in a humid environment (basically humid air), it will start to rot. Does the humidity influence the rotting speed, and if so, what is the relation between the rotting speed ...
5
votes
2answers
357 views

Correlation between genome size and mutation rate?

Martin Nowak in his book "Evolutionary Dynamics" talks about a given correlation between genome size and mutation rate. What correlation does exactly exist between these two concepts? Is it a ...
3
votes
2answers
138 views

How does smoking, an environmental factor, cause cancer, fundamentally a genetic disease?

If cancer is fundamentally a genetic disease, how might an environmental factor such as smoking cause cancer?
6
votes
3answers
192 views

What does it mean for a distribution to be “consistent with a two rate-limiting stochastic steps”?

I'm reading a study (full text here) that examine the dynamic of nuclear translocation of a transcription factor in budding yeast, in response of calcium stress. They found that it occurs in bursts, ...
2
votes
2answers
2k views

Does endo- and (or) exocytosis require energy? Do they belong to active / passive transport?

I expect vesicle formation and fusion to require energy input; however, I'm not sure about which of endocytosis and exocytosis require energy and how they use the energy input. Do they belong to ...
5
votes
2answers
143 views

Transitivity of Species Definitions

There are many definitions of "species" which usually take the form Two individuals are of the same species if ... An implied (rarely made explicit) property of any sensible species definition ...
1
vote
1answer
69 views

Radial Basis Function Network (RBF Network)

In the Wikipedia article on radial basis function network, I didn't understand what was meant by "center vector for neuron i", in other words "center of the RBF units called also prototype".
8
votes
2answers
368 views

What does fitness really mean?

Fitness is certainly the most important concept in the theory of evolution. My question does not have to do with practical measures of fitness but with the theoretical definition of it. I am a bit ...
1
vote
1answer
61 views

Dimethyltryptamine binding site on Sigma 1 type opioid receptor?

I asked this question Dimethyltryptamine and Sigma 1-type opioid receptor interaction but it seems that I didn't express myself well. I was looking for the place on Sigma 1 type opioid receptor where ...
5
votes
3answers
2k views

What is the relationship between sexual and and natural selection?

In http://www.nature.com/nature/journal/vaop/ncurrent/full/nature12701.html, they say: Thus, it seems that the diverse coloration in this species is promoted by both natural and sexual selection. ...
1
vote
0answers
13 views

issues with MultiPipMaker

I would like to use MultiPipMaker for testing a genome alignment between two sequences, each sequence is in .fasta format, but the problem is that when I submit the couples of file that I need, the ...
3
votes
0answers
25 views

What is the origin of viruses? How could they get both living and non-living characteristics? [duplicate]

I read that viruses are called intermediate between living and non-living particles. Well, if so, then where did they originate from? From living or non-living? If they originated from either living ...
1
vote
2answers
148 views

How was the heritability of IQ tested?

I have read that IQ is highly heritable. How could this be tested? For honest testing, it seems to me that only children who were abandoned should have been tested, to exclude education effect. Was ...
2
votes
2answers
226 views

How much natural genetic variation is there between bacteria of the same species?

There are lots of questions about how and why there is genetic variation between organisms of the same species, but I haven't been able to find a numerical value for the expected amount of genetic ...
1
vote
1answer
792 views

What is the physiological difference between snorting/swallowing cocaine

I know that mucosa inside the nose absorbs cocaine molecules when snorting cocaine, but what difference is there compared to swallowing? Also more cocaine administration equals more cocaine molecules ...
4
votes
1answer
88 views

Is it true that there is a spider that eats parasites from caterpillars

I think I once saw a video of a caterpillar that could get infected by a parasite, and could die of that, unless a specific kind of spider would eat the parasite, and so once the caterpillar is ...
4
votes
1answer
66 views

Which is harder to contract - HIV or AIDS?

I am working on mathematically modeling HIV and Tuberculosis Co-infection dynamics, and am working with 12 differential equations describing the behavior of all of the compartments and parameters. ...
3
votes
1answer
57 views

Non-fatal / low-harm measurement of Drosophila traits

I am trying to generate some candidate traits to measure in a fitness assay of wildtype outbred (lab population) flies. The key trait I will measure is lifespan. I am looking for some additional ...
1
vote
1answer
26 views

What Freshwater Fish Are Affected By Magnetic Fields

I am interested in knowing which freshwater fish are affected by magnetic fields. I've heard that Lake Sturgeon are, but would like more references. This is for a project that will have buried 3 ...
1
vote
1answer
63 views

Dimethyltryptamine and Sigma 1-type opioid receptor interaction

Where exactly do dimethyltryptamine and sigma 1-type opioid receptor interact? I read in this When the Endogenous Hallucinogenic Trace Amine N,N-Dimethyltryptamine Meets the Sigma-1 Receptor but it ...
1
vote
1answer
215 views

Why does beta-2-Thienylalanine inhibit bacterial growth?

I'm trying to obtain a better understanding of the Guthrie Test, which checks whether people have a disease called PKU. The Guthrie test uses bacteria to check for Phenylalanine (the amino acid) in ...
1
vote
2answers
42 views

Does a piezoelectric organic substance exist?

that contracts rapidly, in 10 seconds or less, by .5mm or more, when bombarded by electrons as from a cathode ray tube? or expands? could either be living tissue or dead organic matter. thanks!
1
vote
1answer
947 views

How do the first and second law of thermodynamics adhere to breakdown of glucose?

I know the first law is energy can only be converted from one form to the other, therefore in the breakdown of glucose 40% potential energy is converted to ATP and 60% is converted to thermal and ...
1
vote
1answer
143 views

What is an on-line measurement? What is an off-line measurement?

See it used here: http://en.wikipedia.org/wiki/Fed-batch. In the table giving the different strategies to control growth in a fed-batch culture, one finds, for example: "on-line measurement of ...
1
vote
1answer
63 views

Enzymatic Protein Deglycosylation of TCL

I've done O- and N- linked enzymatic deglycosylation of purified and lyophilized proteins. Following some modifications to the manufacture's protocol, I had great results. I now want a student to ...
-5
votes
1answer
178 views

How is it proved, that antediluvian people didn't live for hundreds of years? [closed]

Bible says that antediluvian people lived for 800-900 of years. Nowadays apologists say that it is possible and that we just can't know the truth. I know that one of the basic science principles is ...
2
votes
0answers
18 views

Are there any antigen electronic sensors? [closed]

Is it possible somehow to attach antibody to silicon or to other electronic component chemical, and have electronic detector of correspondent antigen? Does such devices exist?
2
votes
3answers
490 views

Are all body atoms really recycled several times during a life?

I heard a point, that all (human) body atoms are recycled withing short period like few years. Recycled means "old" atoms are replaced by "new" ones during metabolism, leaving only structure ...
2
votes
1answer
125 views

Should the length of the electrodes in the electrophoresis chamber be proportional to chamber's size?

I am trying to build a small horizontal electrophoresis chamber from scratch. I want to use it for comet assay and I will be using only 1 slide, so it's going to be about 3cm wide, 10cm long and 4cm ...
2
votes
0answers
94 views

What causes a selective shift of colour perception after removing wavelength filtered glasses?

Background To improve sleep by reducing blue-light melatonin disruption, I wear night-glasses that filter short wavelengths (e.g. something like these). With these glasses on, both the top and bottom ...
3
votes
1answer
50 views

Where can I find a full genealogy of human cell types?

It is said on Wikipedia, that the precursor of blastocyst is a morula, and that the precursor of morula is a zygote. This gives us the part of genealogy tree of cell types. Unfortunately, no full ...
6
votes
1answer
67 views

How well supported is the hypothesis that aging is mainly caused by the number of mutations in tissues?

I heard the hypothesis, that the (main) reason of aging is the increasing number of mutations in body tissues. The higher the number of mutations is, the older tissue is. Is this true? And how well ...
3
votes
2answers
3k views

Does bright environment strain eyes more than dim?

I'm trying to figure out how to modify my working conditions so that I can program longer without harming my eyes. Because doing so experimentally hasn't given conclusive results so far, I decided to ...

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