4
votes
1answer
108 views

All-or-nothing-law: law or general principle?

The all-or-nothing principle indicates that a nerve cell fires at maximum potential or not at all, based on a threshold on the stimulus. Is this a statement which is always true, or only ...
0
votes
1answer
37 views

What is the best way to block cigarette smoke from the body? [closed]

Would it be better to hold your breath after smelling the presence of it or quickly inhale and exhale to get rid of it in your system(body)? EDIT: Changed from carbon monoxide to cigarette smoke.
15
votes
3answers
7k views

Can the dead be brought back to life by viruses?

Zombies have been a part of popular culture for decades. The living dead rising up to take over the world is a terrifying concept, worthy of Hollywood blockbusters and television hits. Some of those ...
3
votes
0answers
72 views

Why doesn't lard taste good? [closed]

I mean looking from evolutionary perspective sugar tastes sweet and individuals that had this perception ate more sugar and survived and those that didn't perceive sugar as sweet didn't eat it and ...
1
vote
1answer
27 views

How does Organ Transplant work well despite having Foreign DNA

My question is little bit related to this one Why does organ transplant work although it seems organ's motor neuron isn't connected to recipient's CNS but only little bit. Problem ...
1
vote
2answers
55 views

Difference between DNA and Genome

Can we safely use the terms DNA and Genome interchangeably or is there any (even slight) difference between the two?
1
vote
1answer
61 views

Difference between LH and ICSH

Are Luteinizing hormone and Interstitial Cell Stimulating Hormone(ICSH) the same?
3
votes
0answers
38 views

How hard would it be to synthesize a virus in 1960? [closed]

Assuming 1960 technology, how hard would it be to synthesize a virus? Im curious as to how developed technology was back then and the amount of cost and effort it would take given the fairly basic ...
3
votes
1answer
102 views

Which literature/study/myth spurred the idea that urine is sterile?

There is a seemingly unfounded mantra that a person's urine is sterile who is not suffering from a UTI. So far I have found convincing evidence to the contrary; urine is not sterile. This poster ...
8
votes
1answer
99 views

Aquarium snail identification

Many of these little snails suddenly appeared in our aquarium from nowhere. I suspect that some snail eggs hitched a ride with some recently purchased plants. Can anyone identify the species? I am ...
0
votes
0answers
28 views

Why does human waste still contain nutrients for plants?

The question is motivated by the Martian movie, in which the main character (Mark Watney) uses human waste to fertilize Martian soil and grow potatoes. Following the idea that energy can only ...
4
votes
0answers
54 views

How do animals with fur get enough sunlight to produce vitamin-D? [duplicate]

How is vitamin D synthesized in animals with fur; how do the cells get enough sunlight? If vitamin-D cannot be synthesized because of limited sunlight reaching the skin, do these animals have to ...
1
vote
1answer
141 views

Difference between negative allosteric regulation and non-competitive inhibition

Both connect to some site other than the active site which controls the shape of the active site and causes the enzyme to be less active. So what is the difference?
1
vote
0answers
11 views
0
votes
0answers
24 views

Diffusion coefficients of glucose in mammal tissues?

Where can I find estimates/experimental measurements of the diffusion coefficient of glucose in mammal tissues? Specefically I mean the inter-cellular space. I'm not looking for a specific tissue, so ...
1
vote
0answers
25 views

What niche was humanity theorized to fill before we possesd weapons and coordination to hunt & kill large prey?

I'm really interested in evolution, and for a err 'hobbyist' I think I understand a good bit of evolution and adaptation and the role it has played in many species. However, I feel I'm rather ...
0
votes
1answer
35 views

How does protein enter bloodstream?

If a hemophiliac patient injects his factor 8 through the veins directly into the bloodstream to provide the body with clotting factor... Why don't they just make the drug as a pill and have the liver ...
0
votes
1answer
42 views

Normal cell diffusion in normal organism?

We know, that cancer cell can travel across an organism. Is this ABSOLUTELY impossible for NORMAL cells? For example, is it EXACTLY ZERO probability to find some bone cells inside liver or some skin ...
1
vote
2answers
144 views

Density of cells in human tissues?

Where can I find values, or estimates, of the density of cells in human tissues? Maybe an overall estimate, or distinct values for distinct tissues? Or maybe not human, but mammal tissues (which ...
4
votes
3answers
37 views

Identifiying a conserved residue in multiple PDB structures

I have a few hundred PDB structures of the same protein, and I need to identify a specific conserved residue in all of them. Originally I wanted to extract the sequences from the PDB files with ...
4
votes
1answer
66 views

What determines the shape of the center-surround receptive fields of retinal ganglion cells?

The wikipedia article about receptive fields of visual system tells us the following: The receptive field is often identified as the region of the retina where the action of light alters the ...
2
votes
1answer
40 views

What kind of changes “stays” in the neuron after the nervous impulse happened?

I often see in neuroscience textbooks about how the brain controls everything in the body with different tracts and etc, and it seems that information is always being transmitted, like there's no ...
5
votes
1answer
83 views

What is the purpose of THC for a Cannabis plant?

Why does a Cannabis plant produce THC? This question is brought up drawing an analogy to nicotine in tobacco, where nicotine is developed by tobacco plants as a pesticide. Is THC a pesticide as well? ...
0
votes
1answer
39 views

Aspirin - does it inhibit enzyme of thromboxane?

This is a diagram a friend showed me about the drug aspirin, where we were arguing which enzyme it prevents. Aspirin is known to inhibit the production of prostaglandins. However, it also serves ...
4
votes
1answer
79 views

Why do children prefer sweeter foods?

As we get older, we tend to lose our sweet tooth and become more tolerant to bitter foods, like vegetables. However, I never understood how this works. Why is it that children prefer sweeter foods, ...
0
votes
0answers
17 views

Human walking biomechanics: is it pushing, pulling, or subjective?

The horses are divided in various species. Some are genetically better built for traction, others for speed. How about humans? How is our motion, traction like, pushing focused, mixed, or is ...
2
votes
1answer
76 views

How do you know which organisms are keystone species?

I know that keystone species are those that play a crucial role in an ecosystem, but since all species are interdependent upon each other and each occupy their own niche, aren't they all important? ...
1
vote
1answer
40 views

How does cytochrome c oxidase inhibition cause cell death?

I realise the inhibition of cytochrome c oxidase prevents the release of H+ ions into the intermembrane space, and that the ion gradient is required for ATP synthase action. However, I'm not sure how ...
0
votes
2answers
22 views

Can an enzyme be activated without allosteric inhibition or activation?

Are there ways by which an enzyme may be activated or inhibited by non substrate molecules other than allosteric activation or inhibition?
4
votes
1answer
132 views

What is a tardigrade “in tun form”?

While reading this article about tardigrades that had been previously frozen, I came across some verbiage I wasn't sure of and couldn't find any real explanation given the context. The article kept ...
1
vote
1answer
35 views

BWA-MEM single strand or doublestrand alignment

In whole genome secondary analysis does BWA-MEM use a double stranded fasta reference or are reads aligned to only one, single stranded fasta reference?
1
vote
0answers
14 views

What fills the spaces between non-fused sacral vertebrae?

What is in between the sacral vertebrae before they are fused? I have looked and found no specific descriptions. If it is simply cartilage, what type of cartilage?
3
votes
1answer
140 views

Why does Citric Acid occur in Citrus fruits?

Why is there so much citric acid in citrus fruits? And how did it evolve i.e. what did it come from? Is it a by-product of the ripening process? Why have citrus fruit evolved a particularly high ...
0
votes
1answer
25 views

“Heterozygotic expection” - when heterozygote differs from both homozygotes, but homozygotes are similar

For simple 2-alleles genetic model {a,A} and corresponding quantitative trait Q is typically true that Q(aa)>=Q(aA)>=Q(AA) or conversely Q(AA)>=Q(aA)>=Q(aA). For example, dominance means that ...
0
votes
0answers
29 views

Hair whitening with age explanation

I don't understand, why the hairs are whitening with age? Popular explanations look formal to me. For example, an explanation by stopping of melanin production is just a rephrase. Melanin is a ...
6
votes
1answer
40 views

Why aren't plants and animals capable of assimilating $\ce{N2}$ directly from the atmosphere?

From a E-book written by Hungary scientists, the reason is $\ce{N2}$ is inert. Is this correct? How does the chemical properties of gas species ($\ce{SO2}$, $\ce{O2}$, $\ce{NH3}$, etc) ...
1
vote
1answer
54 views

Reason for aquatic plant roots

My question is about why aquatic plants have roots. At first they seem a bit superfluous to me because leaves of the plants could just absorb nutrients directly from the water thereby skipping a need ...
3
votes
1answer
131 views

HOw are AMP's “recharged” to become ATP's in a cell?

I understand that after the translation stage of ribosomal protein synthesis, tRNA molecules are floating in the cytoplasm without attached amino acids until they find the correct aminoacyl tRNA ...
0
votes
1answer
49 views

Will dissolved proteins pass through a 0.2 micron filter?

Given that there may be exceptions, can you usually expect protein to pass through?
4
votes
1answer
78 views

What causes the opaque green colour in Lepidoptera?

Link here to what I mean by 'opaque' colouration on the insect, the colour intensity remains constant despite changes in light intensity and angle (not shown by the picture but the moth exhibits this ...
2
votes
1answer
364 views

Examples of animals with 12-28 legs?

Many commonly known animals' limbs usually number between 0 and 10. For example, a non-exhaustive list: snakes have 0 Members of Bipedidae have 2 legs. Birds and humans have 2 legs (but 4 limbs) ...
1
vote
0answers
52 views

Making mistakes in the laboratory [closed]

I have just started an internship in a microbiology laboratory. I have had a rather small amount of laboratory experience before this so had to learn mostly everything from scratch. I have been there ...
0
votes
0answers
11 views

Where to Find Pedigree-Linkage Data for Computational Pedigree Analysis

I'm currently working on a project that uses graphical models (Bayesian networks) for pedigree analysis. My group developed a few models several months ago, but the original data used to develop the ...
0
votes
0answers
24 views

Determination of Ageing by ECG inclusions/exclusions?

I am studying ageing and considering ECG signal because of its high sensitivity in theory (escardio). Some factors Sensitivity Gender Medical treatment ... Benchmark: RTG dental + wrist ...
1
vote
1answer
41 views

Examples of seeking behavior by brainless animals

Are there any examples of brainless animals (e.g. jellyfish) exhibiting seeking behavior, such as following smell or light gradients towards food, or following hormones towards mates?
0
votes
1answer
72 views

How much do crocodiles eat`?

How much do crocodiles eat? The closest I found to an answer was on german wikipedia, where it says that adult nile crocodiles eat "only about 50 full meals a year." While interesting, without knowing ...
0
votes
0answers
14 views

examples of animals losing their brains when losing their mobility

I'm looking for examples of animals with central nervous systems that start out mobile, but then become permanently attached to something, and lose their brains. One famous example is that of some ...
2
votes
0answers
40 views

Does medication make the body dependent? [closed]

First of, I know of course that certain medication can cause an addiction if incorrectly used. But as far as I understand it, drugs prone to cause addiction have some agent in it, that makes them ...
3
votes
1answer
68 views

Why are sequencing reads shorter than PCR products?

I have desinged and tested primers for RT-PCR, then purified the PCR products from the gels and send them to sequence at GATC (SUPREMERUN) using the forward primers. After blasting the reads to ...
1
vote
0answers
13 views

Does this habit present any harm? [closed]

Sometimes I am able to put one knee down on the floor, rest my weight on that knee, and then relax it in order to make the knee cap go up and "crack" the knee. I can do this with both knees, I think ...

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