2
votes
1answer
16 views

For emphysema, which of the respiratory volumes is effected. I have a couple of educated answers

It could be the tidal volume because it effects how a person inhales and exhales normally. It could be the residual volume and functional residual volume, because it increases its amount. Because it ...
1
vote
1answer
24 views

Earwax versus Mucus

Something I have wondered for a while is why have two different primary defense mediums, ie earwax and mucus, that perform the same function? As far as I know, mucus and earwax are both part of the ...
5
votes
3answers
382 views

Evolution: How could all useful traits evolve simultaneously?

I have a basic question about evolution, for which I never found an answer. I understand how evolution works if we focus on one specific organ or trait. With each generation, some organism is more ...
3
votes
2answers
75 views

Heterozygosity under genetic drift

The wright-Fisher model of genetic drift is: $$p_{ij} = \binom{2N}{j}\left(\frac{i}{2N}\right)^j \left(1- \frac{i}{2N}\right)^{2N-j} $$ ,where $\binom{2N}{j}$ is a binomial coefficient. From this ...
4
votes
0answers
20 views

Evolution of Chromosome Numbers

Some species have different numbers of chromosomes, as we all know. Throughout evolution, how was a species able to survive with an extra chromosome? How was this organism able to breed successfully ...
0
votes
0answers
11 views

Which is the best software for Molecular Biology Graphics? [on hold]

Probably you have seen the beautiful graphics that appear on every article in Science or Nature. I want to get the closer to that result making Molecular Biology graphics with a simple and easy-to-use ...
2
votes
2answers
72 views

Is it possible to have life in vacuum?

I just got struck by curiosity now: Intuition says no, but I've never had confirmation of it.
2
votes
1answer
66 views

dopamine paradox in Schizophrenia

If there is more dopamine action in the mesocortical pathway in Schizophrenia, then the patients should always be in euphoric state. But instead patient lacks motivation and don't want pleasure. Why?
1
vote
1answer
24 views

Correlating B-lactamase expression to absorbance

When penicillin-resistant bacteria are grown in liquid culture media, B -lactamase is secreted into the medium. The supernatant of such a medium can be assayed for B- lactamase activity. Culture ...
4
votes
1answer
117 views

What exactly makes bananas go brown?

I know that often oxidation processes are mentioned when referring to the color change from yellow to brown in bananas (specifically: those that you get everywhere in supermarkets, with no seeds). ...
0
votes
0answers
12 views

Distribution of Physarum polycephalum tubes during starvation phase

So I have been trying to find an answer to this question in the literature but to no avail. I am looking at the Tero and other articles on the slime mold Physarum polycephalum. I understand the models ...
2
votes
1answer
115 views

What is the beneficial function of IgE antibody?

Dont tell me the "function" of IgE is to cause allergy ! In whatever texts I have seen it is written that IgE is important to cause allergies but what is the beneficial function of IgE ? Why was it ...
0
votes
0answers
6 views

What are the mechanisms of disabling extrinsic control of heart?

I started this thread by thinking this question but I developed it further below What is the mechanism maintaining refractory period of pacemakers? My conjuncture is that the mechanism is the ...
0
votes
0answers
22 views

Is there a biological reason for spreading food intake into breakfast-lunch-dinner?

I keep hearing over an over how humans can satisfy their entire daily caloric need in one sitting at a fast food restaurant. At the same time I'm looking at the kitchen plates, cups, etc, and they ...
1
vote
2answers
34 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 ...
1
vote
2answers
43 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 ...
0
votes
0answers
7 views

Which reflex arcs work in Heart with extrasystoles?

I am researching what is triggering the extrasystoles - initial idea from this thread about Which ionic channels of Pacemakers can work in very low frequencies in extrasystole? I am interested in the ...
0
votes
1answer
5 views

Which ionic channels of Pacemakers can work in very low frequencies in extrasystole?

At frequency 0-3 Hz. Like computer processors which can work at low frequencies and controlling under- and overvoltage. Normal most significant channels are Ca2+ and K+ that are changing. However, I ...
10
votes
2answers
244 views

How does the genetic code evolve?

After looking at this question, some other questions poped in my mind. The DNA code is redundant, there are 20 amino acids for 64 possible nucleotide combinations. Therefore some amino acid are coded ...
3
votes
1answer
48 views

relative-rate of evolution

I am supposed to calculate the relative rate of evolution of two sequences (human and sheep) with a chicken serving as the outgroup. The sequences are pretty long, so I will just create a short ...
0
votes
0answers
16 views

Book-recommendations on virus evolution [on hold]

I am seeking for a good book on… Virus evolution Viral population genetics Theoretical virus evolution Mathematical modeling of virus evolution Evolution of virulence Intra and inter-specific ...
2
votes
1answer
212 views

Why do three nucleotides code for one amino acid? Why not 5 nucleotides? [duplicate]

We all know why there are 3-base codons, and why there aren't any 2-base codons. But why is there not a 4-base a 5-base codon?
0
votes
1answer
25 views

how many chemcial species on average in a typical plant and animal cell

I want to know what sort of range there is on the number of different chemical species in a typical plant and animal cell. Failing that, some specific examples (with sources please) Thanks
0
votes
0answers
13 views

Simultaneous depolarisation of Sinus Node and AV node as extrasystole in myocardial infarction patient

Assume you have a patient 68 years old with previous myocardial infarction (Actually patient 201 in MIT-BIT arrhythmia database). Assume that AV node depolarises strongly. However, at the same time, ...
1
vote
1answer
25 views

Troubleshooting for Agarose Gel Electrophoresis

SI ran my 2% agarose gel on constant voltage (100 V). For a few times it worked at CV but, after a week or so the machine would automatically switch to constant current by itself. And this only ...
1
vote
1answer
15 views

Usage of the taxonomic classification “Pinnipedia”

According to ITIS the classification Pinnipedia is invalid, and it is proposed to rather use Caniformia. The later group however includes a range of terrestrial animals as opposed to the pinnipeds ...
10
votes
3answers
190 views

How do we know that dinosaurs were related to lizards and/or birds?

Do we clearly know what the living closest relative of the dinosaurs are? And connected to the first question, in scientific manner how do we know these relationship between extinct species and living ...
0
votes
2answers
19 views

Is Sinus node conduction necessary for heart beating?

Assume a patient with previous cardial infaction which SA node not possible to activate action potential anymore. However, SA trying to beat unsuccessfully repeatedly waisting energy. Therefore, I ...
2
votes
0answers
27 views

Why does IUCN classify pistachio as a “Near Threatened” species?

When reading the Wikipedia entry on pistachio, I noticed that IUCN has classified the plant under "Near Threatened". On looking up its entry at IUCN, I see that its population is trending downwards, ...
1
vote
0answers
44 views

What is the name of systemic tension of muscles?

I meat a overtrained friend (25 years old) who cannot rest. He has all muscles and most of the skin very tense. He is practising regularly in gym and sleep badly. He moves like a stick figure and has ...
2
votes
1answer
32 views

Are there any fungi that can digest humic acids?

Humic acids are a complex group of organic substances, that are generally known to be hardly biodegradable. Fungi as agroup are known for breaking down complex organic matter like cellulose or lignin. ...
1
vote
2answers
39 views

How the lungs clear themselves?

Looking at my computer's fan I can say that a lot of dust is collected on it not less dust should be collected in the lungs, not to mention some inhaled parts of food. How the lungs clear themselves ...
0
votes
2answers
45 views

Databases for metabolic pathways of human disease

Which databases contain the metabolic pathway of human diseases? I have searched Metacyc and KEGG but didn't find the appropriate metabolic pathway.
0
votes
0answers
8 views

Calling for Pressure pictures about Right and Left atrium

I am trying to understand the partially patent foramen ovale in patients with right-side heart failure. I am interested how the pressure in right and left atrium change in normal case in abnormal ...
0
votes
1answer
27 views

Manifestations of open foramen ovale in adults

I read that foramen ovale opens in 30% of adults. I do not know how much of these openings can then close again. Probably, none. It is not pathogenic if no symptoms. It allows blood to enter from ...
0
votes
0answers
6 views

Laser surgery to stop damaged Sinus node from beating

I am trying to find any publication about laser surgery to stop the damaged sinus node which cannot anymore beat. I could only find publications which modifies SA node function. I am not sure if it ...
2
votes
1answer
45 views

Additive genetic variance with $n$ loci

The genetic variance of a quantitative trait (the quantitative trait in question is fitness) can be express as the sum of two components, the dominance and additive variance: $$\sigma_D^2 + ...
3
votes
1answer
48 views

Can oil be used instead of water in preparing wet mounts for microscopy?

Is there a reason that oil (e.g., vegetable or clear mineral) is not used to make wet mounts in microscopy? I am not referring to oil immersion technique but substituting oil for water in wet mounts ...
3
votes
0answers
46 views

Did the eugenics program in Nazi Germany have a measurable effect?

Did the killing or sterilisation of people considered as living a "life unworthy of life" in Nazi Germany have any measurable effect on the "average health" of Germany? Is there any statistical ...
1
vote
2answers
76 views

Does Science Say That We Should Die? [duplicate]

Excluding situations where you die from accidents, the main reason for death is -generaly- diseases. And usually it is about an organ which becomes "tired" after many years. These results are all ...
6
votes
2answers
3k views

Is it possible for a brown eyed parent to have blue eyed child?

Here's the story: A young man has stunning blue eyes. On his mother's side are lots of instances of blue eyes, but on his father's side is no history of blue eyes. When he was born with these bright ...
2
votes
1answer
85 views

Earliest ancestor of humans who could integrate into modern society

Assuming the current model of human evolution to be correct, approximately when did the earliest ancestor of humans live, who was intelligent enough, that if raised from a young enough age, could ...
2
votes
3answers
48 views

The effect of pH on enzymes

I am currently studying biology and have a question. I know that as pH increases, enzyme activity increase until the enzyme's optimum pH is reached. However, I would like to know why as pH increases ...
1
vote
0answers
50 views

What is the biochemical pathway of fluoride?

Fluoride is a common active ingredient in tooth paste to prevent dental caries. It is also added or removed from the water supply in some communities for the same reason, but in children only. My ...
2
votes
1answer
40 views

Evolution from Mating types to different sexes

Imagine a lineage of multicellular organisms that had mating types and evolved their mating types into sexes. What are the possible mechanisms that might have brought this lineage to evolve sexes from ...
0
votes
1answer
35 views

About validation process of phenological study

I have recently done a phenological study using remote sensing techniques. Now I need to validate my results and my methods, that is, to determine if the phenology estimated from remote sensing is ...
10
votes
1answer
1k views

How does translational coupling work in prokaryotes?

Today I heard about a phenomenon called "translational coupling", where the translation of one protein influences the translation of another protein. The messenger RNA levels don't seem influenced. ...
1
vote
2answers
108 views

Hardy-Weinberg Equilibrium: To compute probability of finding two siblings (random mating)

I've been working a little with M. G. Bulmer's Principles of Statistics (Dover, 1979) and cannot see how to properly compute half of one question. This should be a basic probability computation, but I ...
4
votes
1answer
109 views

How does a fungus protect itself from digestion by other fungi?

If a fungus releases its digestive enzymes outside its body, how does it protect itself from digestion? How do fungi growing nearby protect themselves? I have tried searching this on google but ...
2
votes
1answer
232 views

What is Luc Montagnier's research on electromagnetic signals from DNA about?

After reading a Youtube comment, I started reading on Luc Montagnier's research on electromagnetic signals from DNA. I haven't been able to find a source that would clearly explain what it's about. I ...

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