5
votes
2answers
40 views

How and why can cold inflict pain?

I was carrying a can of very cold liquid, had something heavy in my other hand so couldn't switch hands. After a few minutes, I started to feel very intense pain. I was very surprised. cold is just ...
5
votes
1answer
167 views

What physics knowledge can be applied to biology of organisms and ecosystems?

In the wiki page of Biophysics: Biophysics spans all scales of biological organization, from the molecular scale to whole organisms and ecosystems. But after searching on the internet; the ...
5
votes
1answer
87 views

What's the worst that can happen from too much sleep deprivation? Can you die?

It is well known that sleep deprivation causes considerable discomfort in humans (and has even used as a form of torture), but nevertheless there have been people who went through protracted sleep ...
5
votes
2answers
117 views

Can you tell the sex of a white willow when it's not flowering?

Can you tell whether a salix alba tree will produce male flowers or female flowers by looking at it, touching it or generally using your unaided senses? If not, is there any way to do that without ...
5
votes
3answers
182 views

How easy is it to carry out de novo sequence assembly?

Today a colleague of mine asked the following question: " Assuming I need to build from 0, a chromosome of a fish, with short reads but no other reference whatsoever [de novo assembly]: ...
5
votes
1answer
239 views

Variations in Genome Sizes

Why is there wide variation in genome size amongst groups of protists, insects, amphibians and plants, but less variation within groups of mammals and reptiles?
5
votes
4answers
415 views

What is the viability of Intelligent Design as a supplement to chemical abiogenesis and Darwinian Evolution?

First of all I am not endorsing Intelligent Design (Wikipedia link); I'm asking this because I (someone who does not have a background in biology, organic chemistry, or philosophy) got into a ...
5
votes
2answers
144 views

How is gene expression estimated?

I'm reading this fantastic article on estimating body time: Molecular-timetable methods for detection of body time and rhythm disorders from single-time-point genome-wide expression profiles and one ...
5
votes
1answer
905 views

Why our body does not produce polyunsaturated fatty acids?

Our body does not produce two polyunsaturated fatty acids (PUFA): linoleic acid and alfa-linolenic acid. I am thinking reasons for it. Saturated fatty acids have more energy than unsaturated. ...
5
votes
1answer
190 views

What is a Mitochondrial Eve and Y-chromosomal Adam

I've read this question: What kind of event would cause the current Mitochondrial Eve to be replaced by a new one? And the values in Wikipedia about Mitochondrial Eve and Y-chromosomal Adam and I am ...
5
votes
1answer
140 views

What protocol does the nervous system use?

I just read How does an inhibitory synapse communicate to the cell body of a neuron? and found myself asking this question ... hopefully I'm not asking the same thing Any body possessed of a nervous ...
4
votes
1answer
109 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 ...
4
votes
2answers
658 views

Importance of Double Helix DNA Structure

Gene expression involves transcribing only one strand of DNA molecule. So i was wondering what are some biological advantages of the double stranded DNA?
4
votes
2answers
228 views

The gender of offspring of Twins?

Given identical twin males, Michael and Douglas, Douglas and his wife have four children, all of whom are girls. Michael and his wife have only one child, a boy, and are expecting another. What are ...
4
votes
2answers
264 views

What determines the autumn leaf color?

It is autumn out there. Green, brown, red, yellow, and mixed-colored leaves drop from the trees to the ground. What determines the colors of the leaves? Wikipedia tells me Leaf senescence is the ...
4
votes
1answer
102 views

What is the physiological difference between cortisone and cortisol?

There is only hydrogen bond different. Cortisol is synthesized by our body, while cortisone is given to the patient. Why you cannot give cortisol directly to the patient? I think the reason is ...
4
votes
2answers
588 views

Why doesn't the human skin grow back exactly how it was before being damaged?

Very simple: Why (and how) is regenerated skin different from original ? As we know we lose skin cells that becomes the dust in out homes and it always grows back to full thickness right ? So when I ...
4
votes
2answers
176 views

Effect of testosterone hormone on cell signalling and behaviour?

A steroid, testosterone was injected in female body which led to development of secondary sexual characters but these characters were not developed over night (Response was very slow). What could be ...
4
votes
3answers
167 views

Does anyone know a good software for producing tanglegrams?

I'm trying to look at relationships between parasite and host phylogenetic trees. I have done a bit of searching for a software in which to do this with, and I have tried using Dendroscope and ...
4
votes
3answers
340 views

Fisher's Fundamental Theorem of Natural Selection

Ronald Fisher discovered what he, with humility, called the Fundamental Theorem of Natural Selection. This theorem says (in its modern terminology): The rate of increase in the mean fitness of any ...
4
votes
1answer
364 views

Effect of single nucleotide deletion or insertion on primer annealing

How is primer annealing, and, consequently, PCR amplification affected by single nucleotide deletion or insertion inside the primer ? Imagine a primer like this: GCGTCATAAAGGGGACGTG (primer) and ...
4
votes
2answers
189 views

How does the colinearity of the HOX genes determine the body plan of an organism?

I was recently reading about colinearity in the HOX genes that give an organism its high-level body plan (where the order of the HOX genes on the chromosome follow the head-to-tail order of body ...
4
votes
1answer
100 views

Randomness in living systems

The point of my question is not to talk about events that are uncontrolled by living organisms. My question is about controlled randomness, or I'd like to say adaptive random process. Process that are ...
4
votes
2answers
311 views

Are there dangers to Teflon and aluminium cookware?

I've been reading some articles on the internet about dangers of Teflon and aluminium to the body. My family say I'm just exaggerating the situation, and maybe I am, though I'm not sure because not ...
4
votes
2answers
331 views

Extraretinal photoreception in mammals? [duplicate]

A Finnish firm Valkee sells light-ear-plugs against thing such as jetlag. I asked a researcher in Aalto university how do they really work and he responded ...
4
votes
2answers
2k views

Why does alcohol cause the hemolysis of RBC in a large proportion?

I had today an experiment that we put 95% alcohol to the blood which made it completely transparent so hemolysis must have occurred. I started to think about the reasons. I think that this is because ...
4
votes
1answer
105 views

What light intensity determines the start/end of a photoperiod in humans?

I'm reading this article, which discusses the influence of Long Photoperiod (LP) and Short Photoperiod (SP) on melatonin production: HIOMT drives the photoperiodic changes in the amplitude of the ...
4
votes
0answers
112 views

If D1 receptors stimulate adenylate cyclase (through GPCRs) and D2 receptors inhibit it, then why do mutations in both have similar effects?

D1 and D2 both refer to specific types of dopamine receptors. I'm sure it has something to do with the fact that the D1 receptors are in regions different from D2 receptors. I know that adenylate ...
3
votes
1answer
18 views

How does Trifluralin kill newly germinating seeds, with almost no effects on established ones?

Trifluralin (2,6-Dinitro-N,N-dipropyl-4-(trifluoromethyl)aniline) is a pre-emergent herbicide used in landscape beds before the application of mulch (my use for it, anyway). It kills the weeds as they ...
3
votes
1answer
82 views

How to inhibit formation of specific antibodies (to antisera)?

Is there a way to inhibit an antibody response to a specific antigen using immunosupression? I am interested in reducing the anti-antibody formation to animal antibodies such as murine antibodies in ...
3
votes
3answers
176 views

Why does a cockroach not die even after decapitation?

Why does a cockroach not die after its head is cut off?
3
votes
2answers
75 views

How did aquatic dinosaurs go extinct?

Dominant theory is that 'normal' dinosaurs went extinct from ether super volcano or meteor impact or combination of both. However there were aquatic dinosaurs that are not present at this day. Was it ...
3
votes
1answer
55 views

Mechanisms of bone growth

The length of a bone is caused by growth of hyaline cartilage which is then replaced by bone tissue. How do cells know whether they should grow the hyaline cartilage? What are the key molecules that ...
3
votes
2answers
58 views

What is an Ihh-/- mouse?

This one is too basic question: I just came across $Ihh^{-/-}\ $ mouse. Is that means this mouse devoid of that gene Ihh. What is this sign called and are there other such representations?
3
votes
0answers
36k views

Does CPH4 exists? [closed]

I just see the film Lucy, it talks about a molecule called CPH4 which increase human capabilities. Of course it's a film and so it's not scientific facts. During an interview the producer says that ...
3
votes
2answers
111 views

Human Evolution in Modern Times

I understand that evolution occurred to form the current hominids from a common ancestor millions of years ago. As evolutionary processes take a long time, is there proof of evolution occurring with ...
3
votes
1answer
271 views

Where do butterflies sleep?

Do butterflies (insects) sleep, and if so, where?? I have googled for information but didn't get an exact answer.
3
votes
3answers
97 views

Does a reduction in stem cells mean possible earlier death?

The basis of this question relies on my understanding of these 2 facts: ...
3
votes
1answer
88 views

Inbreeding depression and dominance

From this article, second paragraph of the second page A classic theoretical result is that the mean of a character controlled by a single locus i with two alleles Ai1 and Ai2 is only affected by ...
3
votes
1answer
195 views

Why do cockroaches burst from soapy water?

(careful, disturbing!) I was experimenting with some stray cockroaches that ended up falling in my bath tub overnight (there is currently an infestation undergoing in my apartment building) and I ...
3
votes
1answer
114 views

Why insects are so small compared to mammals?

I was wondering what biological limitations make the dimension of the insects small compared to the dimension of the mammals. I know in other eras insect were bigger!
3
votes
1answer
358 views

What is needed for a G-matrix?

I have been doing a lot of reading on quantitative genetics and the G- (and B-) matrix lately. I get the principle behind performing the analysis now but I am still not sure how to do it. I'd like to ...
3
votes
2answers
221 views

Changing the definition of life?

Viruses at this period of time do not fit the current definition of life. Much of the reasoning behind this is that we currently believe that all life must be made up of cells. Also, many ...
3
votes
1answer
374 views

What hair color will result in someone inheriting both blond and ginger genes?

Both the genes for blond hair and ginger hair are recessive, so they need both parents to give the same gene for it to take affect. What happens when a person has 1 copy of a recessive gene and ...
3
votes
1answer
293 views

Is there a difference between pig and cow anatomy that makes religious slaughter of the latter less painful?

This question is not for the squeamish. I was told that non-Kosher animals like pigs have a different anatomy in their neck compared to kosher animals like cows such that the Shechita method of ...
3
votes
1answer
177 views

What is the difference between vegetable and fruit?

Is there any exact definition of vegetable and fruit? How can new plant be classified?
3
votes
1answer
249 views

Is there an “Adam and Eve” for each new trait during (not just human) evolution? [duplicate]

Do new beneficial mutation evolve simultaneously and independently with several individuals of the same specie or only with one specimen who then transfers it to all of the specie? In other words, ...
3
votes
1answer
175 views

Does an allergic reaction kill body cells?

I have wondered what actually happens in an allergic reaction that causes the symptoms such as pain, rash etc. Is it possible that the human body actually kills its own cells in the process?
3
votes
4answers
740 views

Which came first: The Chicken or the Egg? [closed]

Has there been any serious scientific inquiries into answering this age old question?
2
votes
1answer
32 views

Identification of unknown bagworm (Singapore)

This bagworm was found in Singapore (near McRitchie Reservoir) some time in June 2012. This is the plant from which the bagworms were obtained: A few examples of the bagworms: The bagworm when ...

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