5
votes
2answers
587 views

Why did the urinary bladder evolve?

Sure it's convenient to decide when to urinate but not essential for survival or reproduction, as I understand. But just convenience is not a drive for evolution. Does the bladder serve any essential ...
7
votes
2answers
272 views

Can spider silk be synthesized for 3D printing with spider silk?

With the recent rise in 3D printing, I keep hearing about more novel ways to use the technology: cell 3D printing, liquid aluminum or plastic 3D printing. For example, this Ted talk deals with ...
3
votes
1answer
118 views

Why seeds won't sprout given excess water?

What would cause a seed to not sprout despite showing signs of germination given excess water? Oxygen, temperature, and light were sufficient for germination and sprouting in seeds of a slightly ...
2
votes
2answers
119 views

Lactose Intolerance

What nutrition is given to infants who are lactose intolerant? I understand, in today's day and that age we have non-lactose formula milk, but what happened, before lactose-free milk was created, to ...
4
votes
1answer
60 views

HSL Lightness vs Eye sensitivity

In a monochromatic spectrum, is the human eye equally able to distinguish between lighter colors just as it is in distinguishing between darker colors? I mean is there really a linear relationship ...
1
vote
0answers
27 views

Can Opioids Attenuate some of the symptoms of Psychosis?

Can Opioids Attenuate some of the symptoms of Psychosis? I ask because there's a dead link on the Wikipedia page http://en.wikipedia.org/wiki/Opioid_dependence#Causes that's meant to support the ...
4
votes
1answer
450 views

Are there predators evolved to eat puffer fish?

Puffer fish is known for having a anti-predation defense mechanism of having toxin-exuding spikes. Are there predators which evolved specifically to prey on puffer fish? (presumably, by evolving ...
4
votes
2answers
187 views

Gas from bacteria that's not methane

Is gas produced by bacteria always mainly methane? Or, are there bacteria out there that produce some biogas composed mainly of hydrogen, natural gas, propane, butane?
6
votes
1answer
195 views

How was the first ribosome theorized to have been made?

Seeing as ribosomes are what help perform the act of translation itself, and the blueprints for they themselves are in nucleotide sequences, how was the first ribosome theorized to have been made? ...
3
votes
1answer
1k views

How much does donating blood affect the amount of oxygen in your blood stream at high altitude?

I am a regular blood donor and I am also a skydiver. We normally go to around 13,000 feet AGL (above ground level). Depending on how high above sea level the ground is, altitudes could be as high as ...
1
vote
0answers
25 views

Which Enzymes Degrade Dynorphins and what drugs are there available to inhibit said enzymes?

Which Enzymes Degrade Dynorphins and what drugs are there available to inhibit said enzymes?
4
votes
1answer
265 views

Does frequency of eye blinking reveal anything about human biology/nervous system?

I'm looking at an output of a single dry sensor EEG headband with the sensor positioned above left eye. As a side effect of it's placement, the device picks up eye blinks, and some eye motion as ...
4
votes
1answer
65 views

Do ant pheromones indicate the direction to go?

I know that ants communicate with pheromones but I am wondering if these pheromones can indicate in which direction to go. For example the ants leave pheromones to indicate a food source and when they ...
0
votes
3answers
216 views

Can this theory on the evolution of human appearance be flawed?

This is what a friend of mine said: When there's human offspring, it will look a rough 'medium' between the two parents, with it sharing features from the two. well if the offspring of one set ...
8
votes
1answer
221 views

Are animals that live in areas where avalanches happen equipped to deal with that?

Humans take courses to learn how to assess the risk of avalanches and how to deal with it. Additionally, they often use special gear to survive avalanches if they got caught in the middle of one. ...
1
vote
1answer
377 views

What is the difference between abiogenesis and spontaneous generation?

As we all should know, abiogenesis and spontaneous generation are far from identical. For one, spontaneous generation was disproven with Pasteur, and abiogenesis seems to be a solid scientific theory. ...
5
votes
1answer
2k views

How does plant grafting work?

Plant grafting is a process whereby a piece of one plant is inserted into another and results in a change of the original plant. For example, grafting a piece of a lemon tree into a bitter orange tree ...
1
vote
0answers
51 views

Polymerase Observations [closed]

DNA polymerase I (PolI) contains polymerase, 3'-5' exonuclease, and 5'-3' exonuclease activities in a single polypeptide chain of molecular weight 109 kDa. If E. coli Pol I is exposed to the protease ...
1
vote
1answer
3k views

How does inorganic phosphate inhibit alkaline phosphatase?

I want to know how is inorganic phosphate able to inhibit alkaline phosphatase.
11
votes
2answers
545 views

Do plant-animal cross races exist?

Plants and animals have the following distinct properties: Plants live from solar energy by photosynthesis, they use solar energy to make sugar and oxygen out of carbon dioxide, which gives them ...
2
votes
1answer
51 views

Confusion related to the DAVID tool

I am trying to use the DAVID tool to do some gene analysis. I have some probe set intensities for some cancer cell lines. I found this link in the DAVID tool http://david.abcc.ncifcrf.gov/tools.jsp. I ...
0
votes
1answer
99 views

Do women have greater reproductive success than men? [duplicate]

What proportion of men who go through their whole lives and never find a mate at all, and what proportion of women do? And is the proportion of men greater than the proportion of women?
0
votes
1answer
86 views

What species of bird is on this coin? [closed]

What species of bird is depicted on this coin? http://www.artic.edu/aic/collections/citi/images/standard/WebLarge/WebImg_000100/139651_846511.jpg Thanks in advance for your help!
5
votes
3answers
175 views

What are the limitations of commercial-grade DNA genotyping compared to full sequencing?

I've heard about services like 23andme, which offer genetic testing to the general public. As a person who knows very little about genetics, I'm interested in the subject and would like to know what ...
2
votes
0answers
42 views

Can the Human body Synthesise Vitamin D from Phytosterols?

I know that the human body can synthesise vitamin D from cholesterol, but can it do so from phytosterols?
3
votes
1answer
607 views

Difference between “transcriptional activity” and “RNA expression”

I am working with a network object where the nodes are different events in molecular biology. Specifically; Catalytic activity of X, RNA expression of X, GTP-bound activity of X, Kinase activity of ...
7
votes
5answers
343 views

Are there examples of encryption in nature?

There are examples of mathematics in nature such as Fibonacci number, fractals, etc. Are there examples of encrypted information? What I am looking for is a pattern that seems random on the ...
6
votes
2answers
2k views

Very high 260/230 absorbance ratio of an RNA sample

After my most recent RNA extraction, the RNA samples had very high 260/230 absorbance ratios, (ranging from 5 to 25). I've never gotten numbers like this and I know the ratio is supposed to be ~2 in ...
5
votes
1answer
401 views

Solvent Accessibility, the 20% cut-off method

I'm reading the papers linked below and all three of them mention a 20% cut-off for buried/exposed residues, by calculating a relative solvent accessibility (RSA) value. I understand how the RSA is ...
8
votes
3answers
3k views

Why doesn't recombination occur in male Drosophila?

"Males do not show meiotic recombination, facilitating genetic studies." For a while I have known that this phenomenon occurs, this quote comes from the Wikipedia page on Drosophila melanogaster, ...
7
votes
2answers
512 views

Does every human eye see the same visible spectrum?

It is said that human eye can see light with wavelength approximately between 400nm and 700nm. Are these upper and lower bounds same for every human? If not, what are the means and standard ...
10
votes
1answer
10k views

Can a person really die quickly from biting their tongue?

A common trope in certain circles (like Eastern martial fiction), is someone committing quick suicide by biting his or her tongue. But is this really possible? The internet turns up millions of ...
4
votes
1answer
178 views

How can the child and the mother have different blood types?

As far as I know the fetus is fed by the umbilical cord which basically connects his/her circulatory system with the mother's in order to supply oxygen and nutrients. But how is this possible if they ...
3
votes
3answers
81 views

When can I assume individuals marrying into a pedigree are non-carriers?

If I'm not told that they're non carriers, and if I don't have proof of their geneotype based off of progeny, when can I assume they're non carriers for a trait?
2
votes
1answer
4k views

Melting point of a fatty acid?

What factors determine the melting point of a fatty acid? Chain length The number of methylene group The ionized state of the fatty acid Its degree of saponification Its ability to alter the ...
5
votes
1answer
106 views

Is 1 g/l living biomass for a Biogas fermenter plausible?

A usual number for a healthy biogas fermenter is $10^9 - 10^{10}/mL$ Bacteria, 10-15% of which would be methanogenic archae. Exceptionally healthy fermenters have more total bacteria and up 25% ...
2
votes
1answer
15k views

I'm 20. Can I still grow taller? [closed]

I'm 20, in about 6 months I turn 21. For some time I've been wondering whether there are natural, non-surgical and non-pharmaceutical ways that humans can continue to grow after reaching adulthood. ...
6
votes
1answer
228 views

Primary cilia: what cell types have non-motile cilia that migrate?

My understanding is that there are two broad categories of cilia: motile and non-motile (also called primary. Examples of the former include sperm flagella and the cilia of epithelial cells that ...
3
votes
1answer
22 views

How long does it take for the Opioids listed in the Description to induce Analgesia when Administered via IV?

How long does it take for the Opioids listed in the Description to induce Analgesia when Administered via IV? Now I don't mean how long it takes for euphoria to come on but analgesia. The opioids I ...
5
votes
1answer
459 views

Are there grass or fiber eating birds?

My understanding, that may be wrong, is that cellulose/fibre has little nutritional value to many animals because it's hard to break down thus making consumption inefficient. However, Ruminating ...
2
votes
0answers
52 views

What's the Efficacy of Ampakines in the Treatment for ADHD?

What's the Efficacy of Ampakines in the Treatment for ADHD? Ampakines are a class of drugs that serve as potentiators of the AMPA glutamate receptor. By so doing they serve as nootropic, anxiolytics ...
4
votes
3answers
189 views

How does natural selection favour large body mass and size (or so it seems)

I was walking through a park this afternoon and observed a few birds having fun flying around and it got me thinking why would natural selection favour birds with flesh at all if it hinders their ...
4
votes
1answer
348 views

What plastic eating organisms are there to help with plastic in landfills problem?

I see some popular science articles on the plastic eating bacteria and fungi appearing on the web since 2009. Most of the articles praise discoveries, because such organisms promise to break down ...
8
votes
3answers
7k views

Why can ATP not be stored in excess?

I just learned that ATP can not be stored in excess and is only made by the body when it is needed. What makes ATP, like glucose and fat is what is stored under the skin or wherever. Now why cant the ...
1
vote
1answer
105 views

What factors must be taken into account for the maintenance of the immunogenicity of ovalbumin antigen?

What factors must be taken into account for the maintenance of the immunogenicity of ovalbumin antigen? If the ovalbumin is aggregated, could we inject it for induction of immune reponse?
7
votes
1answer
78 views

Cell Respiration and Oxidative Phosphorylation

Why and how does the proton travelling through the stalked particle in the inner mitochondrial membrane, cause a conformational change in the ATPase?
5
votes
2answers
3k views

Does ethanol destroy RNase?

I've gotten conflicting advice on this: some people believe one can remove RNase contamination simply by spraying the bench, pipettes, gloves, etc. with ethanol. Others think ethanol does not destroy ...
1
vote
1answer
209 views

Is it true that oxygen has a diffusion rate in air 10,000 times greater than in water? [closed]

According to the Wikipedia page on the design of gills, oxygen has a diffusion rate in air 10,000 times greater than in water. Is that true? The WP entry refers to: M.B.V. Roberts, Michael Reiss, ...
3
votes
0answers
862 views

What are the factors to consider when determining the sample size for a given study?

Say I'm designing a retrospective study (where I'd collect data from various schools for the last 5 years) to see if consuming milk can contribute to childhood obesity. How do I decide on how many ...
2
votes
1answer
203 views

Where would Saccharomyces cerevisiae be found in highest concentrations in environment?

I have bakers asthma specifically to 'Sc' yeast, and know to avoid bakeries, breweries, etc... I have figured out to not disturb rotting leaf piles, and fermenting bark mulch. Where else? What ...

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