All Questions

3
votes
1answer
408 views

Ka/Ks (dN/dS) analysis module for Python?

From this wiki article: In genetics, the Ka/Ks ratio (or ω, dN/dS), is the ratio of the number of Nonsynonymous substitutions per non-synonymous site (Ka) to the number of synonymous ...
7
votes
3answers
157 views

How should I put a large phylogeny into a scientific paper?

I've been trying to put a phylogeny tree into a scientific paper. This tree includes ~220 species, which is too too large for one page for journal articles (Letter or A4 size). But in my paper it is ...
1
vote
1answer
45 views

Clownfishes and Sea anemones

Relation between clownfishes and sea anemones is a classic example of mutualism. I wanted to list the species of sea anemones that are involved in this mutualism but I got lost.. Could you help me ...
4
votes
4answers
178 views

Why has evolution made neurons use spiking?

I'm going to be forward and say that I'm not a biologist. I don't claim to fully understand the functionality of a neuron from an electrical/chemical perspective... I'm curiously gazing from the ...
8
votes
1answer
97 views

Dogs bark at familiar person in Santa costume. Why? Don't dogs trust smell over vision?

Last night 10 humans and 2 dogs spent Christmas together. At some point, one human dissappears for a few minutes and comes back wearing a full Santa outfit. Upon respawning, the dogs start barking ...
3
votes
2answers
70 views

Identifying whether ELISA kits are authentic or fake

What methods can be used to determine whether they are authentic or fake?
1
vote
0answers
16 views

When do chimeras happen?

If one developing twin absorbs another, when does that happen? Is it possible for an appendage or organ to develop and be the only remaining vestige of an absorbed twin, such as a hand or a mouth, or ...
3
votes
1answer
109 views

Is there a limit to twinning?

Can developing twins further divide and subdivide and become identical quadruplets or octuplets or...? Can twinning be induced, either in utero or in vitro? Might it be possible to just keep ...
2
votes
1answer
70 views

When does identical twinning happen?

What is the window during which division into twins is possible (for instance can it still happen after implantation in the uterus)? Is one twin the "original" and the other its clone?
3
votes
1answer
42 views

Why genes are assumed to follow multivariate normal?

I wonder why gene expression data are very frequently modeled by multivariate normal distributions. What is the reason for those strong assumptions that the genes follow multivariate gaussian? Are ...
2
votes
1answer
59 views

The arrangement of retinal cells?

The section of retina shows a layered arrangement of the various retinal cells. Starting from the inside (where the light strikes first) is the nerve fibre layer, ganglionic layer, amacrine cell ...
-2
votes
2answers
77 views

Why it is rare for person to get infected with two Pathogens?

Why is it rare for a person to have 2 (or more) infectious diseases (for example: Flu & Cold together at the same time)? Although it's rare, it happens when the immune system is weak (e.g when ...
4
votes
1answer
44 views

Are original x-ray diffraction data available

Is it customary for investigators to publish the original x-ray diffraction data used in macromolecular structural determination? If not, why not; and if so, is there an online database where these ...
7
votes
1answer
104 views

Can cancer cells in the same person, organ, and origin have different DNA?

Is it possible for cells from the same tumor to have different genetic material, and if so, to what degree is it possible (how fast do they mutate) ?
3
votes
1answer
89 views

How Much Longer For The Gene For Blue Eyes?

In the year 1900 roughly 50% of the people in the United States were homozygous for the gene for blue eyes. By 1950 the number had dropped down to 30%. Just now, (2013) barely 12% of the people living ...
4
votes
2answers
115 views

How do detergents get in hydrophobic membrane interior?

According to Molecular And Cellular Biology (Stephen L. Wolfe), Membranes disperse almost instantaneously if exposed to a nonpolar environment or to detergents, which are amphipathic molecules ...
4
votes
2answers
66 views

Is the empty GI tract a hollow tube with air inside, or is it generally collapsed until food is eaten?

I have heard that "air in the GI tract" results in flatulence and burping etc, however I initially assumed that the "empty" GI tract was a hollow tube filled with air anyway. So on an empty stomach ...
1
vote
1answer
38 views

Is this maritime plant a species of zostera?

This photograph was taken on the intertidal mudflats at Lindisfarne, Northumberland, UK today. It was about 40m from the shoreline at low tide. Is the green plant a species of zostera? Can anyone help ...
1
vote
2answers
86 views

Are there free electrons in muscles, hair, or skin?

Electric shock occurs upon contact of a (human) body part with any source of electricity that causes a sufficient current through the skin, muscles, or hair. In metals many electrons are said to be ...
2
votes
2answers
3k views

Why is dimethyltryptamine (DMT) being released during death?

I'm not very well informed about all the things related to biology and the current achievements of science in this field so if I'm wrong in anything I say, please let me know. Many times I've come ...
1
vote
0answers
27 views

How far does the diaphragm stretch when it contracts?

I have been wondering about this for this entire day today and I can't seem to find an answer. How far, exactly, does the diaphragm stretch for tidal breathing and what is its maximum stretch length?
0
votes
1answer
91 views

Current human behavior as a genetic heritage

People: I have doubts about genetic heritage, but let me explain the context which has shown up this doubt for you: I was debating about sexism and the following question were put on the discussion: ...
1
vote
1answer
64 views

Determining limiting nutrients from a graph

The question was Which of the following statements is supported by these data? A. Phosphorus was the first limiting nutrient followed by nitrogen. B. Nitrogen was the first limiting nutrient ...
0
votes
1answer
52 views

How does a prophage leave the host cell's genome?

I understand that, unlike a prophage, a provirus never leaves the genome, but I don't understand how the prophage "leaves".
2
votes
1answer
83 views

Is light required for seed germination?

Is light required for germination of every seed? If not, why don't some plants require it? Is there any difference in the quality and duration of light required ? It would be interesting if someone ...
1
vote
1answer
71 views

What is a phospho-protein binding domain?

Is this just a domain that binds proteins that have been phosphorylated? And it mediates signalling between an activated/phosphorylated protein? How is this significant with BRCA1?
1
vote
1answer
63 views

Colchicine addition to cells

When is colchicine added to dividing cells for karyotype studies? I know that colchicine inhibits polymerization of microtubules. 2 So, why should it stop the cell cycle at metaphase when ...
1
vote
0answers
91 views

Transcription takes place from the 5’ to the 3’ end of the m-RNA. Why?

Only one side of the DNA ladder is copied (the sense side). The sense side starts with a 3’ end. This means the corresponding mRNA will have to assemble starting from the 5’ end. This is my initial ...
3
votes
1answer
35 views

When was it determined that Type 1 Diabetes is an autoimmune disease?

I just found out today that type 1 diabetes is an autoimmune disease. When was this discovered?
5
votes
2answers
57 views

Standard Classification of Disease

I am working on a project for health center. It involves the creation of a database of all diseases. Currently I want to classify disease on the base of their category based on international standard. ...
1
vote
0answers
51 views

What is the life span of southern versus northern animals? [closed]

How long do wild animals of the northern hemisphere live compared to those of the southern hemisphere and based on their growth span. Particularly large mammals and particularly animals of similar ...
1
vote
0answers
35 views

Paired-end mapping exercise

Pair-end mapping (PEM) is a technique that allows to detect structural variants in DNA by obtaining paired-end reads and the comparison of their positions in a reference genome. Then among libraries ...
7
votes
2answers
495 views

Can humans transdermally absorb minerals from ocean water, and if so how much?

According to several studies quoted here, chemicals can be absorbed by the skin transdermally, at least under certain conditions. When it comes to elements in seawater like sodium, magnesium, ...
1
vote
0answers
24 views

Temporal effects on pathways?

I was wondering whether or not there exist certain pathways that are triggered by a temporal signal. We're almost at the winter solstice now. Does animal or plant function involve signals that are ...
5
votes
2answers
86 views

Confused at what is happening with these action potentials

Ok so for a bit of a background, I am doing a science project looking at the action potentials of the earthworm. I anaesthatized the worms then hooked them up to a spiker box ...
0
votes
0answers
21 views

Does amylolysis occur in vegetables if stored under 0 Celsius?

Assume that we have a plant, e.g. kale, which is prone to amylolysis if not harvested during a frost period. If it is harvested and put in a household freezer, such that it is frozen solid slowly ...
0
votes
1answer
283 views

Why temporal lobe is called temporal?

http://en.wikipedia.org/wiki/Temporal_lobe Does this have something to do with tempo (time?) Temporal lobe is behind (posterior) to frontal lobe, inferior to parietal lobe and is in front of ...
2
votes
0answers
42 views

Autoimmunity and central tolerance

Where in the body are self antigens important? In terms of central tolerance and autoimmunity, but also in terms of T cell activation?
3
votes
1answer
118 views

How much influence does toxoplasmosis have on personality and intelligence?

Latent toxoplasmosis effects up to 1/3 of the human population, and up to 40% of the population in Australia. I have heard that latent toxoplasmosis has many significant undesirable effects on ...
1
vote
2answers
88 views

Photosynthesis: Splitting Water

The splitting of water is an endergonic (non-spontaneous) reaction, and thus would require energy (chemical work to be done) in order to happen. In Photosystem II, an enzyme catalyzes this splitting, ...
2
votes
2answers
96 views

Phospholipid Bilayer structural reversal

What would happen if the phospholipids in the phospholipid bi-layer were reversed, the fatty acid tails now facing outwards and the phosphate heads facing inwards? I'm assuming this will not affect ...
1
vote
1answer
41 views

reason for “not for diagnostic use” advice in protocols

I read "not for diagnostic use" in every protocol i saw. why is it so? which differences have the kits and material that are used for diagnostic purposes?
3
votes
3answers
76 views

Is there a downloadable list of all species along with their traditional classification?

I'm looking for a downloadable list of all known (or better said, online documented) species in this straightforward format, as an example the European Frog: Kingdom: Animalia Division: Chordata ...
1
vote
1answer
60 views

Can pets catch the cold?

Last night I was drying my cat with a towel after shenanigans in the rain and she sneezed! Questions Can cats/dogs/hamsters or other pets catch the cold? How quickly do they recover?
1
vote
2answers
116 views

How likely is it that Earth has millions of different species?

I know that the probability of life existing on a habitable planet is pretty slim. But, how likely is it that it hapenned millions of times in the same planet? Or was it only a few species that ...
4
votes
1answer
84 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 ...
3
votes
1answer
81 views

Is there a molecular basis to intelligence?

Is there any explanation, gene(s) or whatever detected, that are co-related or explicitly related via mechanical bio-molecular (or at any other level) models that explain the higher or lower ...
4
votes
2answers
101 views

Ethidium bromide and mutagenesis on cloning

When performing a DNA cloning, sometimes PCR amplicon is run in agarose and it is detected by ethidium bromide marking under UV light. After that, gel is sliced, DNA extracted from gel....... until ...
5
votes
2answers
97 views

How much DNA of mitochondrial origin is incorporated in main cell's DNA?

And especially three points : in which chromosomes is it located (especially for the human case) ? how do we know about it ? does the proportion and composition vary a lot from one eukaryot to ...
3
votes
0answers
43 views

Database of Medical Assertions

Can anyone point me toward a computationally-accessible database of medical assertions? I'm looking for something where each row in the database contains a single unit of knowledge. It could either be ...

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