17
votes
3answers
302 views

What is the reason behind choosing the reporter gene when experimenting on your gene of interest?

I noticed within example experiments in class that different reporter genes are chosen to be inserted near your gene of interest to prove whether or not the gene is being expressed. For example, you ...
17
votes
2answers
605 views

Why should a tumor look like a crab?

Origin of the word "cancer" The disease was first called cancer by Greek physician Hippocrates (460-370 BC). He is considered the “Father of Medicine”. Hippocrates used the terms carcinos and ...
17
votes
4answers
1k views

Why does the cold make us sick?

From the moment we learn to communicate, we always get told, whether by our parents, or our teachers, or by anyone else, to avoid the cold, or to put a jacket on to avoid catching a cold, to dry our ...
17
votes
1answer
421 views

How does Sodium Valproate cause neural plasticity

I have been reading a fascinating paper: Valproate reopens critical-period learning of absolute pitch 18 individuals were given Sodium Valproate (VPA) for a fortnight during which they trained on a ...
16
votes
3answers
2k views

Do animals exist with an uneven total number of digits?

I recently finished reading Contact by Carl Sagan. In the book they talk about a pattern in the transcendental number like pi or e, and comment that it is found in base 10 or however many fingers the ...
16
votes
9answers
6k views

Why didn't the polar bear change its color from white to black during evolution to absorb heat?

Polar bears are white in color and white color is not a good absorbant of heat. Why then didn't they evolve a black color to absorb more heat?
16
votes
4answers
2k views

Where’s the flaw in my proposed TB Treatment?

Ten years ago, I emailed a prominent lung specialist with my suggestion for a treatment for Tuberculosis. His lack of response led me to believe that the idea had no merit whatsoever – but I had no ...
16
votes
4answers
2k views

How can homosexuality evolve despite natural selection?

I would imagine that the answer to this question would be population control, especially since even if one sibling is homosexual this does not necessarily mean that the other siblings will be too.
16
votes
3answers
1k views

Are there cats with black skin?

Some mammals can have a black, pink or spotted skin, depending on race - see for example humans or pigs. But I recently learned that this is not the case with mice. Even black furred mice have pink ...
16
votes
4answers
4k views

Why do parasites sometimes kill their hosts?

It's bothered me for a while now. I understand why a parasitoid would do this, as it only temporarily requires the host, and that not all parasites kill their hosts. There seems to be no evolutionary ...
16
votes
2answers
1k views

How do plant galls form?

I am curious how Gall Wasps, bacteria and other organisms induce galls to form. Specifically, what chemicals induce gall formation?
16
votes
4answers
2k views

Could we transmit smells electronically?

We can encode sound and images in radio waves and send them, but presumably there's some physiological reason that we can't easily make a picture or video of a smell. Could we realistically break ...
16
votes
3answers
69k views

NADH vs. NADPH: Where is each one used and why that instead of the other?

I know NADH is used in cellular respiration and NADPH is used in photosynthesis. What difference does the phosphate group make that the same one isn't or can't be used for both? Is there a greater ...
16
votes
2answers
13k views

Why do people have antibodies against other blood types?

The ABO blood type divides each blood type according to whether they have the "A" and "B" antigen(s) (AB has both, O has none). People also have antibodies against the antigens they don't have (AB has ...
16
votes
1answer
5k 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 ...
16
votes
2answers
1k views

Are single-celled organisms capable of learning?

I've read that the amoeba is capable of learning. Since these protists have no nervous system, it's safe to assume that even highly simplified learning mechanisms of the Aplysia are miles off in the ...
16
votes
1answer
813 views

Do large animals often evolve into smaller animals?

There are several examples where the largest animals were killed off preferentially due to a major ecological shift: The KT extinction event The Holocene extinction, as well as the major megafauna ...
16
votes
2answers
4k views

How many humans have been in my lineage? Is it almost the same for every human currently living?

If I were to count my father, my grandfather, my great-grandfather, and so on up till, say chimps, or the most common ancestor, or whatever that suits the more accurate answer, how many humans would ...
16
votes
3answers
3k views

What causes a 'stuffy' or 'runny' nose when you have a cold?

When humans get the common cold, a common symptom is a stuffy or runny nose. Is that the body's immune response or is that the virus's doing?
16
votes
3answers
2k views

Do probiotics survive digestion?

Pretty much this. I've been wondering if any of the yogourt and other "health" foods containing living probiotic cultures survive digestion to populate our intestines? If so, is there peer-reviewed ...
16
votes
2answers
264 views

Why is there now only one Salmonella species?

Once upon a time, I chanced upon an old microbiology book that detailed the rather colorful world of enterobacteria. Salmonella in particular stood out, as it seemed there were a lot of species: typhi ...
16
votes
1answer
1k views

How old is the oldest intact DNA?

DNA fragments are known from bone fragments from the Mesozoic, but these don't count. I'm guessing the oldest DNA is recovered from permafrost, but how old exactly?
16
votes
2answers
17k views

What is the difference between local and global sequence alignments?

There are a bunch of different alignment tools out there, and I don't want to get bogged down in the maths behind them as this not only between softwares, but varies from software version to version. ...
16
votes
3answers
2k views

What is this fish?! Is it even real?

According to a guy in a Facebook group I belong to, this fish was caught in the Missouri River near Omaha, NE, US. I have never seen one like it in my life, not in person or photo or anywhere. What on ...
16
votes
2answers
9k views

How many people are required to maintain genetic diversity?

Imagine humans were to colonize a distant planet and it was a single one-way trip. How many people would they need to bring? Obviously 2 is the minimum, but that would result in a lot of inbreeding. ...
16
votes
1answer
387 views

Why does mint oil feel cold on the skin?

When putting (japanese) mintoil on the skin it produces a cool feeling. You can experience this, when adding it to your bath or using a spray with mint oil on your skin. The cool feeling occures ...
16
votes
4answers
428 views

Machine learning for light microscopy — problems to solve?

I would like solve some biological problems that would improve the state-of-the-art of biology or bioinformatics. In particular, I want to apply machine learning on light microscopic images. The ...
16
votes
4answers
1k views

Why do we laugh?

Why is it that the reaction we get from absurdity is laughter? Everyone does it, even babies. Is there a reason why it is our instinct to laugh when we see or hear something absurd/humorous
16
votes
1answer
27k views

Fish “coming back to life” after being frozen

I've encountered a clip on Youtube showing a goldfish thrown in liquid nitrogen and immediately after to normal water and swimming normally. In the explanation to the clip it says: For everyone ...
16
votes
2answers
4k views

Is there an advantage to linear chromosomes?

The DNA copying enzymes have a hard time working to the end of a chromosome. For circular chromosomes this is not a problem, since there is not a sharp 'end'. However, for a linear chromosome, without ...
16
votes
2answers
6k views

Why is glucose our primary source of energy?

Is there any evolutionary reason for glucose being the "main" molecule used as a source of energy, beginning with glycolysis and subsequently cellular respiration (after being converted to two ...
16
votes
2answers
7k views

How many organisms have ever lived on Earth?

I've looked for some information on this, but couldn't find anything useful. Has there been any noteworthy attempt to estimate the sum amount of individuals of all species that have ever lived on ...
16
votes
2answers
491 views

Can parts of a human brain be asleep independently of each other, or vary in the times required for them to fall asleep?

I know that some birds and marine animals can continue complicated activity (swimming, flying?) while one hemisphere of their brain is asleep. I'm interested if human brain has some parts of it that ...
16
votes
5answers
11k views

Origin, or source, of rhesus negative in human blood

This is my first post here, so please be gentle. I recently learned that I have Rh- blood (I'm A-), and was idly looking into blood types on Wikipedia. I was surprised to find that relatively few ...
16
votes
1answer
525 views

Do marine deep sea life forms exhibit circadian rhythms? If so, what entrains them?

I've been reading a lot about circadian rhythms, when suddenly this question popped into my head: do circadian rhythms exist for deep sea organisms (3000 ft / 1000 meters+)? For land mammals, the ...
16
votes
1answer
129 views

What effect does a bat's echolocation have on other bats?

Bat echolocation is a perceptual system where ultrasonic sounds are emitted specifically to produce echoes. By comparing the outgoing pulse with the returning echoes, the brain and auditory nervous ...
16
votes
1answer
630 views

Additive genetic variance components from LMER in R

I've set up some dummy data in R which makes 40 genetically related lines, they are all siblings within a line so are genetically related by a factor of ½ thus additive genetic variance should be ...
15
votes
1answer
7k views

Why doesn't water enter my body through my anus or genitals when swimming?

So when we swim, we can make water not enter through our nose and mouth, simply by holding our breath. However, the mouth and the nose aren't the only cavities. What about the anus and the genitals? ...
15
votes
3answers
62k views

What is a coupled reaction and why do cells couple reactions?

I was wondering what exactly a coupled reaction is and why cells couple them. I read the wikipedia article as well as several others, such as life.illinois.edu but I still don't get it. Could ...
15
votes
3answers
1k views

What evolutionary explanations are there for death?

I know death and cancer doesn't hurt humans' reproductive success. It's not helping either. Why do we die? Why dying humans (all of us) are common? What's the point of dying?
15
votes
6answers
1k views

Could Junk DNA be used as a Turing Machine by nature?

In what ways has DNA been studied to see if there a "programmable" aspect to it? Has nature produced anything resembling a Turing machine within the cell, perhaps using the "junk DNA" as its code? I ...
15
votes
2answers
5k views

How and why did mammals go back to the oceans?

If I understand evolutionary biology correctly, mammals first evolved on land as small, rodent-like creatures, in a time when reptiles were dominant on land. Eventually, they diversified into the ...
15
votes
4answers
4k views

Height and natural selection in humans?

I watched the documentary "Evolve" recently and in the segment on "size" Scott V. Edwards, Harvard evolutionary biologist mentioned the idea that humans might evolve to be 7' tall in 'hundreds of ...
15
votes
4answers
3k views

Why would a single celled organism evolve to be multi-celled?

I read a story this week on Richard Lenski who has been 'evolving' E. coli for more than 50,000 generations now. One comment I read was from someone who doesn't accept Evolution who pointed out that ...
15
votes
3answers
4k views

Are there any motile plants?

There are numerous examples of sessile animals (sponges, barnacles etc.) but are there any examples of motile plants? If not, why not? Surely mobility would have conferred an evolutionary advantage to ...
15
votes
3answers
616 views

What is the most difficult feature to explain evolutionarily? [closed]

I wonder what are examples of organs/structures/behaviours/cooperation that evolutionary biologists themselves find most difficult to explain -- to explain how they could appear evolutionarily -- ...
15
votes
2answers
2k views

Why is 70% ethanol preferred for aseptic techniques?

Are other concentrations (say 80%) less effective,or is this just for convenient manufacturing? Is the concentration chosen only because it is less volatile than 100 percent ethanol and hence safer?
15
votes
2answers
2k views

What's the difference between male and female?

As long as we only look at humans the differences are clear: males have chromosomes XY, produce sperm and don't get pregnant. Females have chromosomes XX, produce egg cells and bear babies. But when ...
15
votes
3answers
2k views

Transmission of epigenetic regulation through surrogate mother

I know the basics of epigenetics, but I do not know how epigenetic mechanisms are transmitted from parents to children (or if there is even enough literature to derive a consensus). My question is ...
15
votes
2answers
5k views

Do identical twins have the same fingerprint?

When there is every thing same from their genes to their phenotype so then why they don't have same fingerprints?

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