3
votes
2answers
228 views

How does the brain know where a signal came from? What is the addressing system

I am an electronic engineer so I am thinking about this from an electronics outlook. How does the addressing system work, As I see it, the nervous system is small parallel branches attached to larger ...
3
votes
1answer
146 views

Empirical evidence for Group Selection?

A controversial concept in Biology "Group Selection", has caused confusion and conflict amongst scientists since the since the mid 1990s. The more general realm of study is termed the "unit of ...
2
votes
1answer
88 views

What's the purpose of colorful mushrooms' caps?

What's the purpose for many mushrooms to have colorful caps? Is not it is in their interest to hide as well as possible? Or there are mushrooms that propagate by being eaten, like fruits? Why not all ...
2
votes
1answer
92 views

Does recombination increase the additive genetic variance for fitness?

On this article, first column, eighth line of the introduction: By bringing together favourable alleles from different chromosomes, sex and recombination increase the additive genetic variance for ...
1
vote
2answers
211 views

Has medical progress stopped human evolution? [duplicate]

We can cure many diseases nowadays, and thus the natural selection is very limited. Plus, mankind spent the whole beginning of its existence in almost the same hostile environment, and that's where he ...
0
votes
2answers
709 views

Why have humans evolved conciousness?

Why did humans/animals evolve to become self-aware of their own thoughts. That is, why don't humans act and compute like a machine, or walking zombie. In my mind, such creatures would still be as ...
18
votes
2answers
334 views

Can an adult without genetic lactase persistence still develop a tolerance for dairy foods?

While investigating the rise of adult lactose tolerance, I came across the news that China has been encouraging its citizens to drink more milk, even though most of the Asian population lacks the SNP ...
13
votes
2answers
981 views

Why do we get runny noses in the cold?

The most annoying thing for me about being cold is a runny nose. Is there an advantage to having a runny nose when cold? What does having a runny nose achieve?
12
votes
2answers
2k views

Will humans and animals be harmed by frequencies outside their hearing range?

The human ear (for example) is sensitive to frequencies from 20Hz to 20kHz. Any sound beyond that limit would not be heard by us naturally. Will it harm us (effect our ability to hear) when we hear ...
11
votes
4answers
5k views

What nutrients can humans absorb in the mouth?

For instance, I realise being able to absorb simple sugars in the mouth is pivotal in the rapid action of oral glucose gel. Thus I was wondering what nutrients in general can be absorbed directly ...
10
votes
1answer
2k views

How to DIY preserve pet DNA today so that it can be used in 20 years

I know that there are companies that offer a kit+storage of your pet DNA for around $2k. My question is if there is any other option for doing this yourself with a thought in mind that in 20+ years ...
10
votes
2answers
2k views

How is eye color in humans inherited?

In high school we studied the inheritance of eye color, as it was explained to us in the most simple way: blue eye color is a recessive, monogenic, autosomal trait. Now I know that it is a bit more ...
9
votes
2answers
1k views

What percent of your blood can you lose before you need a transfusion

Losing a little blood is okay. If your a normal healthy person, and got into an accident, how do they know if you need a transfusion or if you'll be okay? This is hypothetical.
9
votes
1answer
179 views

Seeing strange things in light

I have noticed that if you look directly at tubelight (I have only white ones in my home) and close your eyes little, you see little random shaped colourless things sometimes with slow speed and ...
9
votes
3answers
4k views

Why does human facial and head hair continue to grow?

Many people can grow extremely long head hair and facial hair. Are there evolutionary theories as to why this is the case? It seems like having long hair could be a disadvantage, and extremely long ...
9
votes
1answer
345 views

Does DNA react in all of the ways most other acids do?

As I understand it from my basic chemistry, there are some fundamental reactions that exist between any acid and other substances for example acid-base reactions that form a salt, and the existence of ...
9
votes
1answer
92 views

Which patterns do I have to avoid when modifying the 3'-UTR?

I want to change a pre-miRNA sequence (in my case the pre-miRNA is encoding in a 3'UTR of a gene) and then put it in a lentivirus to see if it is still processed. After modification (permutation of ...
9
votes
1answer
564 views

How does laser surgery correct accommodation problems?

When someone undergoes laser surgery to improve eyesight, how does it correct accommodation problems? Why does it not help presbyopia?
8
votes
1answer
3k views

Why can't humans drink sea water?

Why can't humans drink sea water? It would seem to be a huge evolutionary advantage for an animal to be able to drink sea water rather than have to rely on fresh water, and it's provably not ...
8
votes
2answers
660 views

Is it possible to live without health problems sleeping one day and not the other?

Basically, I want to know if it would be humanely possible to sleep one day, skip the next, sleep, skip, sleep, skip, etc, with a 8 hour sleep time. If you need any extra information, let me know.
7
votes
1answer
2k views

Why aren't organelles considered alive?

I'm taking a 3-week Bio I summer course, and my textbook says the cell is the smallest/basic unit of life. I asked my professor why organelles aren't a living unit, and her reply was that they aren't ...
7
votes
2answers
507 views

How do we know the brain flips images projected on the retina back around?

Why do we turn images upside down again rather than dealing with them directly, still vertically rotated after passing through our lens? I don't see how that would cause any problems, and how we'd ...
6
votes
1answer
176 views

Why did humans lose their fur?

The little amount of body hair humans have don't seem to be of much use for keeping warm. Our Simian cousins on the other hand sport thick furs. At which point during the species evolution and why ...
6
votes
1answer
94 views

Sugar as a defence against bacteria?

An answer on another SE site mentions that sugar "at a certain level acts as a preservative". I've always been taught that microorganisms eat sugar and expel acids, that is why sugary food are ...
6
votes
2answers
210 views

Can forensic DNA analysis be used to generate a visual approximation of a suspect?

In light of the current US supreme court case, I'm curious if enough information can be teased out of a DNA sample to get a "reasonable" approximation of the suspect (never mind the legality). I ...
5
votes
2answers
98 views

Functions of the CFTR gene?

I am a senior in high school and I am studying cystic fibrosis. I don't quite get the function of the CFTR gene as this is my first time dealing with this type of heavy scientific info. I had ...
5
votes
3answers
105 views

If someone were to die on the moon, would their body decay?

I heard that the footprints of Neil Armstrong are still there, so I was wondering if someone were to die there, would they remain preserved, too? If not how long would it take for them to decay?
5
votes
3answers
262 views

Can extinct animals be cloned?

Scientists have found mammoth blood, and are planning to clone a mammoth. How does one go from having its blood to a full blown living mammoth? Is it possible? Why does it matter if the blood is ...
5
votes
2answers
7k views

Why are 3 nucleotides used as codons for amino-acid mapping in DNA?

DNA is made of 4 unique nucleotides. When coding for a protein, a sequence of 3 nucleotides is used to code for each amino acid. Why are codons 3 nucleotides in length? A related question can be ...
5
votes
2answers
150 views

HIV Rapid Tests

The hiv antigens that are used in the oral rapid tests, are they infectious? The tests do not contain any actual virus but I am curious if the antigens themselves could somehow create the virus on ...
5
votes
1answer
877 views

The genetic and physiological origins of laughter?

This Wikipedia article defines laughter in many terms, such as... "a visual expression of happiness, or an inward feeling of joy" and "a part of human behavior regulated by the brain, ...
4
votes
2answers
56 views

Can the human eye distinguish colors in the periphery?

In the back of my mind I have the idea that human eyes can't notice the color of objects in the far periphery, and that any subjective perception of colors is done by the brain that tries to fill in ...
4
votes
1answer
51 views

Microbial Fuel Cell Reaction

I found a formula online which explained the reaction which occurred in the anode chamber of a microbial fuel cell but there was a typo $\small NADH + Ferredoxin_{(ox)} (NADH-Ferredoxin\ ...
4
votes
2answers
442 views

In biosynthesis of cysteine and methionine, where does the sulfur come from?

Methionine and Cysteine are the two amino acids containing sulfur. According to wikipedia, cysteine is built from methionine. However, the wikipedia also claims that methionine is synthesized from ...
4
votes
3answers
2k views

What is the equivalent of shutter-speed in Human eye?

I just learned that in video cameras, every frame of the video has its own shutter speed. And I know how frame-rate in human eye works out, well, not completely, hence the question. ...
4
votes
3answers
460 views

Identification of an Insect (Hemiptera)

I found a a few of these guys on my composter, so they could have easily been eating bugs or decaying organics (or both): To me it looks like a stink bug with oversized legs, not like the ones I'm ...
4
votes
1answer
247 views

How quickly can the human heart rate rise and fall?

How quickly can the human heart rate rise and lower? For example lets say a human heart rate is rested and is at 60BPM and that person is suddenly scared to trigger their fight or flight reaction. ...
4
votes
2answers
2k views

How would a plant sprout and grow in a zero gravity environment?

Have any experiments been carried out involving sprouting and growing plants in a zero gravity environment? If so, what was the outcome? How did the plants sprout out of the soil without gravity? Did ...
4
votes
1answer
2k views

What are differences between formation of embryonic disc in chick and mammal embryo?

Exam question which got lowest average points in my university: 1/5 average. No markscheme available so my attempt below. I assume that embryonic disk prefers to germ disk such that Formation prefers ...
3
votes
1answer
67 views

If two definitive ovums are fused will they form an organism?

Pretend that somehow in a laboratory two definitive ovums (finished 2nd miotic divisions) are are fused together. Will they form a new species?
3
votes
1answer
50 views

What is the film that covers the tongue?

What is the film that covers the tongue in the mornings, even after brushing the teeth and tongue the night before and why does it have color variations? Do the different colors mean anything?
3
votes
2answers
86 views

Humidity for wood rotting

If I put a piece of wood in a humid environment (basically humid air), it will start to rot. Does the humidity influence the rotting speed, and if so, what is the relation between the rotting speed ...
3
votes
1answer
2k views

Why do you need you room dark for melatonin release?

There is a light pollution movement that says lighting at night obstructs melatonin production. They say: What makes you fall asleep are changes in the level of the hormone melatonin ...
2
votes
0answers
61 views

Why Mammals are unable to produce Essential Fatty Acids?

While we have to get them from our diet and if they aren't taken in our diet we will face disease.Then why we don't have the enzymes which are require for EFA synthesis???
2
votes
1answer
155 views

Why are hybrids infertile?

Let's take a quote from Wikipedia about zebroids. Donkeys are closely related to zebras and both animals belong to the horse family. These zebra donkey hybrids are very rare. In South Africa, they ...
2
votes
1answer
155 views

List of heritability estimates in humans?

Many people on this site ask questions that directly or indirectly have to do with heritability in human. Do you know a list of estimates of heritability of various traits in humans? Or could you try ...
2
votes
2answers
97 views

Real time PCR normalization algorithm

When performing normalization of real time PCR results, I found two ways of doing it: In my lab they follow the next layout: $efficiency^{-(CT\ interest\ gene - CT\ housekeeping)}$ each time ...
2
votes
1answer
134 views

What insect is this..?

Can anyone tell me what kind of insect (if it is one) is this...!! Or is it the pupa of some insect? Well I don't think that the whole big thing is the insect itself, it appears to be just a kind of ...
2
votes
2answers
123 views

Sources for common laboratory Saccharomyces strains?

I'm used to working with bacteria - some of the more common laboratory strains sometimes come with an order from some vendors. What's the most convenient source to order common straings of ...
2
votes
1answer
546 views

Is there any advantage of having a mitochondria for aerobic respiration?

If we consider the pathway of breakdown of glucose which includes glycolysis, the citric acid cycle and the electron transport chain, all these processes takes place in some prokaryotes and ...

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