5
votes
2answers
53 views

How long can the brain survive during ongoing cardiac arrest?

There was this interesting discussion on CPR and defib in response to the question "Why can't we defibrillate the heart within 1 minute after ventricular fibrillation by electroshock?". Now I was ...
9
votes
1answer
70 views

Does the nervous system have “routers”?

Does the peripheral nervous system have a system of routers that decide where a message is meant to go based on some kind of address, or does a signal from the brain follow a single, unbroken chain of ...
2
votes
1answer
40 views

Safety of using industrial water for hand washing

Industrial water taps are present in most biology laboratories I have been too. There are accompanied by a sign stating "do not drink". So obviously it is not a good idea to drink it. However I ...
2
votes
1answer
34 views

Do bacteria with multiple flagella move faster than bacteria with a single flagella?

Do bacteria with multiple flagella move faster than bacteria with a single flagella? Assuming the flagella are at the same length.
4
votes
1answer
20 views

Mean and standard deviation of human bone density?

Are the human bones about equal in density? Or is there any published data on the mean + s.d. density for a given bone available?
5
votes
2answers
79 views

Why can't we defibrillate the heart within 1 minute after ventricular fibrillation by electroshock?

We mostly can defibrillate the heart before 1 min of ventricular fibrillation by electroshock.Then we often can't do defibrillate it with electroshock. What's the reason and What's the best way to ...
0
votes
1answer
22 views

Why do some cells like myofibrils have multiple nuclei?

I see that myofibrils (muscle cells) contain not one, but multiple nuclei. Why is this so? Do all the nuclei participate in cell division?
5
votes
2answers
67 views

Why don't myopic people see the world upside-down?

I found this image while reading optical instruments in physics. If we look at the uncorrected rays, we see that the image they outline gets inverted. So why don't people with myopic vision see ...
2
votes
2answers
52 views

What effect does the Barr body have, in relation to female Turner syndrome?

Why do persons with Turner syndrome have developmental abnormalities, when normal XX-females do not, even though they only have 1 active X chromosome? From what I know, one X-chromosome is ...
5
votes
1answer
36 views

Why do the size of the phase 1 notch vary among cardiac cells?

The size of the phase 1 notch varies among cardiac cells. It is prominent in myocytes in the epicardial and midmyocardial regions of the left ventricular wall and in ventricular Purkinje fibers. ...
5
votes
0answers
32 views

How does trees know to balance themselves so that they never fall down [duplicate]

Well i was flying kites today I saw a tree and its branches were spread around in random directions... I would like to know that how do these trees know to nourish their branches in some direction so ...
0
votes
0answers
31 views

Is the molecule nitric oxide responsible for healing blood vessels?

Is the molecule nitric oxide responsible for healing blood vessels? How does nitric oxide heal the blood vessels? I watched a documentary about the healing effects of nitric oxide. In the video I ...
7
votes
2answers
80 views

How can we measure cardiac output?

I could find a way which could find it by body oxygen consumption and there is another way to measure it by injecting drugs — measuring cardiac output by the so-called “indicator dilution method,” a ...
8
votes
2answers
100 views

What is the human ear's temporal resolution?

What is the smallest sound duration that the human can hear? In other words, what is the lower duration limit for a sound to be translated into electrical signals by the ear? Suppose the human ear ...
1
vote
0answers
26 views

Eye strain using 3D screens

I don't know if this is a physics or a biology question but this might be better orientated around the element of how the human eye works in a 3D visual situation than physics. Given the rise of 3D ...
4
votes
1answer
201 views

Pasteurisation of orange juice and Vitamin C

In the UK at present, one of the examination boards has set a "controlled assessment" (an experiment that pupils do at school under exam conditions) that involves testing a hypothesis that vitamin C ...
10
votes
3answers
2k views

How much energy does a lion contain? [closed]

I was looking into the following problem: Obviously, the solution lies in how much energy either can output per unit of time. The total energy output of the sun is $3.8×10^{26} \frac{J}{s}$. The ...
6
votes
2answers
42 views

If higher levels of atmospheric oxygen can lead to larger animals, can it also lead to larger plants?

According to some information, in the ancient past (at least some) animals grew larger due to a higher levels of oxygen in the atmosphere. So for example there is this study regarding dragonflies. ...
5
votes
1answer
32 views

What happens when someone is stung by a jellyfish?

What happens in the human body when someone is stung by a jellyfish; namely a box jelly. Judging by what I have heard about the stings I'm guessing that they involve a neurotoxin. But what is ...
5
votes
1answer
32 views

Do people grow shorter as they age, how common is it, and what triggers it?

Is it true that people become gradually shorter as they age? If it is, is it more common in one gender than the other? And is it known what triggers this? (Considering that the "shortening" probably ...
1
vote
1answer
49 views

Why is leucine amino acid used the most in proteins and tryptophan the least?

The amino acid leucine, is used in proteins more than others. Leucine with 9.1 percent (its average in more than 1.150 different proteins) is used most and tryptophan with 1.4 percent is used less ...
0
votes
0answers
20 views

Real Time PCR Test Chemistry

I am working on building a real time PCR machine. Is there any chemistry set that I can purchase online to: Identify if PCR amplification was successfully done. Test fluorescence dyes that could ...
3
votes
2answers
46 views

What virus transforms full grown plants?

I read an article by a gardener describing how a virus had transmitted a negative trait to his plants. It rather shocked me, because I hadn't realized that a virus could transform an adult plant. I ...
2
votes
1answer
64 views

A colony of humans are sent to an alien world, at what point would the descendants evolve to be genetically incompatible with Earth humans? [closed]

I recently heard about the evolution of the London Underground mosquitoes, and how they have changed genetically enough that they almost can no longer reproduce with above ground mosquitos. Since this ...
6
votes
1answer
36 views

Are there ways to speed up the growth of plants?

I'm interested in what humans can do to speed up the rate of growth in a plant. I'm interested in both the context of home gardening and large-scale, institution-backed projects. Obviously, optimal ...
8
votes
1answer
559 views

Why do dog's eyes glow green on a photo?

Taking my current profile picture as a prominent example: This photo has been taken with flash. As I gather, this is the same effect that makes a human's eyes glow red on photos, namely the ...
0
votes
1answer
42 views

Which sex of trees bears fruit? [closed]

Which sex of trees bears fruit? The males or females? And what specifically cause that one to bear fruit. Is it the same as it is with blossoms in trees?
2
votes
1answer
19 views

Plant dependence on CO₂ levels

I was wondering which kind of plants would survive longest without CO2 : plants with fatty, thick leaves or plants with thinner, less fatty leaves? And can we conclude that the plant species that are ...
0
votes
0answers
16 views

Typical in-vivo protein concentration

I am studying RNA-binding proteins involved in RNA granules. I am searching the literature for an order of magnitude of the absolute global concentration in the cytoplasm. Although I am aware this ...
1
vote
1answer
31 views

How to do a whole genome analysis of Multidrug-resistant Mycobacterium tuberculosis

I'm looking for tutorials and software that can help me study whole genome sequence data is and genome wide associations. I have Matlab and Bioconductor R so anything involving those packages would be ...
1
vote
1answer
45 views

How is the reflectance spectrum of solids measured?

I was reading this question about autumn leaf colors. One of the answers refers to an article by Archetti et al. In the article, box 4 (page 5) shows the reflectance spectra of leaves of different ...
4
votes
1answer
145 views

Can concentration of a protein be determined from a gel quantitatively (rough estimation)?

I've got a His-tagged protein in 6M urea, 500 mM imidazole buffer that needs to be quantified before dialysis to ensure there's enough protein worth dialysing. I ran out of my elution buffer which ...
0
votes
0answers
21 views

Does antibody staining / immunolabeling block or inhibit protein function?

In dissociated cells, does staining them with an antibody block the protein's function? How can one assess if the protein is still functional?
1
vote
0answers
19 views

Why didn't we develop senses that allow us to sense radiation, magnetism or any other thing?

Excuse me for my naive question. I just watched one of the episodes of Cosmos, and he mentioned about how we developed eyes during the evolutionary process. The argument proceded by arguing that eyes ...
2
votes
1answer
53 views

Why can't we call dog breeds different species?

I understand this question might fall into opinion based, but I'm trying to write it so that it meets the "Many good questions generate some degree of opinion based on expert experience" part and not ...
3
votes
0answers
22 views

Why does human hair grow and behave differently depending on its location?

Why does human hair behave differently depending on its location? For instance, head hair grows to an indefinite length, but eyebrows maintain a particular length and appearance. Head hair and ...
5
votes
1answer
231 views

What is this plant …?

I would like to know what is this plant ? Does anybody have an idea ? Somebody offered it to me but there is no explanation about how to care about it... Some purple flowers appeared, during 2-3 ...
1
vote
0answers
14 views

negatively charged albumin as major carrier of acidic/negative charged drugs in blood

I reading that orsomucoid (alpha-1-acid glycoprotein) is the major carrier of positively charged (basic) drugs in the blood, while albumin carries negatively charged (acidic) and drugs with neutral ...
4
votes
1answer
68 views

Is a Ginkgo tree a conifer?

I know Ginkgo is a gymnosperm, but I was wondering whether Ginkgo is also technically a conifer. I did a Google search, and found several confident authoritative-sounding answers. Unfortunately, those ...
2
votes
1answer
39 views

Is there any knowledge of physics can be applied in to evolution?

I have asked a similar question in Biology.SE (What physics knowledge can be applied to biology of organisms and ecosystems?), but it just about organisms and ecosystems, not evolution. After watching ...
2
votes
1answer
47 views

What are the requirements for a spectrometer to be used in biological research?

Suppose one would do spectrophotometry on biological materials. What would be the minimum requirements for the measuring device so that the results could be published in a reputable journal? I suppose ...
2
votes
1answer
95 views

How does most of lymph get back into the blood stream? (I don't mean the lymphatic system)

I once read that it was because of osmotic pressure that it returns to the blood stream, by entering the venules. But why? If lymph originated as plasma how come that the solute concentration is ...
2
votes
2answers
95 views

Why do we have more male infant born?

For every 104 male babies,we have 100 female babies and there is a Statistics which is more reliable (we have 997 female infant born per 1000 male infant born). what's the reason? why do we have male ...
1
vote
0answers
20 views

Is this description of etiology of celiac disease correct?

There is a detailed and, to my inexpert eyes, plausible description of the etiology of celiac disease and other autoimmune disorders posted here: http://no-gluten.org/CeliacDisease.htm Is it is at ...
2
votes
0answers
25 views

Double stranded is more 'durable' than single stranded stuff?

I'm struggling with a question I've been asked. "Why is double stranded genetic material more 'durable' than single stranded one?" I know that double stranded genetic material is more stable due to ...
2
votes
1answer
30 views

Is there any disadvantage to having a really low adipocyte count in our times?

The key feature of adipocytes seems to be energy storage. Today humans in Western countries don't have to hunger and have therefore less need to store energy in fat cells. Do adipocytes have ...
7
votes
1answer
72 views

Why is an allele dominant or recessive? [duplicate]

Alleles refer to duplicate genes, where one allele can be dominant over the other. What makes an allele dominant or recessive, given that both code for a single protein?.
5
votes
1answer
64 views

What is the name of this plant? (found in a rock)

I found it in Western Turkey.It was growing on a rock so what's it?
0
votes
0answers
15 views

Retinal eccentricity to colour sensitivity [duplicate]

Colour perception goes out to 50 degrees but is the sensitivity to RGB. Question is it the same in the four quadrants of the retinal field? That is if the red colour sensitivity eg is 30 temporal ...
3
votes
2answers
41 views

What does the gene name “lexA” stand for?

It is an important gene expressed in E. coli that represses the SOS response and also the expression of lambda lytic phase genes. UV light and damage to DNA is responsible for its breakdown and hence ...

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