13
votes
2answers
4k views

How will rising carbon dioxide levels in the troposphere affect photosynthetic producers?

Much discussion has been had about the affects of climate change on plantlife, but how will rising carbon dioxide concentrations affect the photosynthetic process itself? Since CO₂ is a reagent in ...
13
votes
2answers
394 views

Evolution in 37 years, is it possible?

I am confused, can evolution ( speciation ) really occur in such a short time ? In 1971, biologists moved five adult pairs of Italian wall lizards from their home island of Pod Kopiste, in the ...
13
votes
3answers
543 views

Why is there a difference in the rotation of the tail fin in fish compared to marine mammals?

I've been thinking about this one, but I can't seem to find what causes this difference. All fishes that I've seen have their tail fin positioned vertical: But all the marine mammals I know have ...
13
votes
2answers
496 views

Intrinsically disordered proteins as potential drug targets

Intrinsically disordered proteins (IDPs) are a class of proteins that do not adopt a stable secondary or tertiary structure under physiological conditions in vitro, but still have biological ...
13
votes
3answers
1k views

What implications has the missing 2'-OH on the capability of DNA to form 3D structures?

The chemical difference between RNA and DNA is the missing 2'-hydroxyl group in the nucleotides that build DNA. The major effect of that change that I know of is the higher stability of DNA compared ...
13
votes
2answers
6k 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 ...
13
votes
2answers
630 views

Does testosterone increase female sexual behavior?

According to my lecture notes testosterone generally increases sexual behavior. Given that it's generally thought to be the male hormone I'm not quite sure whether they mean that it also increases ...
13
votes
2answers
3k views

What effect does vortexing have on a fluid sample that simple mechanical shaking does not?

Some protocols call for fluid samples to be mixed with a "vortexer" on the high setting. What effect does the vortexing have on fluid samples that mechanical shaking does not? Does it shear long ...
13
votes
2answers
256 views

Percentage of genome devoted to regulating gene expression

Recently I've been studying the p53 tumor suppressor gene as a model for regulation of gene expression. It's amazing how many different post-translational modifications are known to regulate p53 ...
13
votes
1answer
3k views

How does a plant grow before photosynthesis is possible?

During photosynthesis, a plant translates CO2, water and light into O2. I assume the carbon C is further used for the growing process. I wonder how the plant grows before the time where photosynthesis ...
13
votes
2answers
917 views

Is the EC50 of an activating protein for an enzyme a good indicator for the binding affinity Kd?

We work with a membrane protein system where measuring the affinity between the enzyme and the upstream activating protein has been difficult, and when measured in detergent solution, it is almost 100 ...
13
votes
1answer
3k views

Why does Penicillin only affect bacterial cell walls

I was quite fascinated by the feature Should Science Pull the Trigger on Antiviral Drugs—That Can Blast the Common Cold? in this month's Wired magazine. They explain that Penicillin is effective at ...
13
votes
3answers
788 views

Why do restriction enzymes tend to have an even number of bases in their recognition site?

When reading my textbook I noticed that in all examples but one from eight the recognition site was an even number of bases. I wondered if this was just a co-incidence, so I took the data from this ...
13
votes
2answers
543 views

Are there neurons that can sense light shining in your ears?

I know someone who bought earphones that shine light in you ears. According to what he was told, there are neurons that sense light and then make you feel wide awake when activated, which seemed like ...
13
votes
4answers
2k views

Why is the Hydra Biologically Immortal?

I have heard that the Hydra organism is biologically immortal (later I found that there are more immortal organisms). Now I know that its immortality is related to its telomerase. The thing is that we ...
13
votes
2answers
13k views

Possible? When a pregnant woman suffers an organ damage, fetus would send stem cells to the damage organ to help repair it?

I am quite sure that there is this blood-placental barrier between the mother and the baby so that nothing (except a type of antibody) can pass through it. But I remember reading somewhere that when ...
13
votes
2answers
490 views

Which is more important for protein expression mRNA structure or codon optimization?

The field seems extremely divided on the debate. On one hand, artificial experiments have suggested that synonymous mutations don't correlate with gene expression but rather, the mRNA 5' structure is ...
13
votes
2answers
421 views

What is the morphological difference between Leydig cell in human and pig?

The pig is only an example, just an animal. Leydig cells have protein inclusions (Reinke crystals) that are mostly made of crystallised lipofuscin. They are secretory inclusions i.e. cells formed in ...
13
votes
2answers
187 views

How is menstruation not suicide in the wild?

Watch any wilderness special for more than a few minutes, and you'll notice a familiar pattern: when a predator catches the scent of blood on the wind, the hunt is on. Wounded animals make the best ...
13
votes
3answers
287 views

Can plants get cancer?

I can't think of any reason why plants wouldn't be able to get cancer, but I've never heard of a plant growing a tumor. I've also never seen a plant with a noticeable abnormal growth. Can plants get ...
13
votes
2answers
3k 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. ...
13
votes
1answer
905 views

Are human bodies programmed to die?

Following from this question: What is the evolutionary advantage of death?: Is there any evidence that human bodies have systemic self-destruction built into their developmental program? I'm not ...
13
votes
2answers
426 views

Why are there N's after Sanger sequencing?

After sending a DNA sample for sequencing, the resulting sequence had N's in the beginning and end of the sequence. I know the N's mean that the computer can't tell what the base pair is, but why is ...
13
votes
1answer
9k views

What effect has changing pH and salt concentration on protein complexes?

I'm struggling to find peer reviewed literature that explains the effect of changing the pH and the salt concentration on protein/protein complexes in solution. What effect does the pH and the salt ...
13
votes
1answer
488 views

How do porcupines keep from pricking each other while mating?

How do porcupines keep from pricking each other while mating? It seems like they would constantly be scratching each other.
13
votes
1answer
622 views

How many people's DNA were involved in the compilation of the reference human genome?

I know that the reference human genome is complied from DNA portions from different people, most of whom were European. Do you know how many of them were involved? Do you know which ones were ...
13
votes
2answers
325 views

When does BLAST fail to align 2 DNA sequences?

This is an assignment that had confused me for a long time. So I think you guys who study computational biology might be interested. The original question is: Find the two most similar DNA ...
13
votes
1answer
1k views

Why do we have five fingers?

Humans (and other humanoid mammals) have five fingers in each hand. Curious to know, why five? Wouldn't more fingers be more useful? Is there any evidence that it used to be different and natural ...
13
votes
4answers
285 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 ...
13
votes
2answers
383 views

What kind of fruit is this?

Just spotted this fruit while walking to school. It's the size of a small coin.The taste is almost sour and tangy and somewhat sweet (I only tried one of them and very little of it). I admit, ...
13
votes
1answer
220 views

How does herpes (HSV) infection suppress HIV?

HIV compromises the human body to defend against infection. Yet people who are infected with herpes are at less risk of developing AIDS. How does this work?
13
votes
2answers
226 views

What is the contribution of viruses to the evolution of mankind?

I'm interested in horizontal gene transfer in bacteria, viruses, and organisms such as Bdelloid Rotifers. I've just read in Carl Zimmer's 'A Planet of Viruses' the following passage: As a host ...
13
votes
1answer
15k views

Are mosquitoes repelled by high frequency sound?

I am totally confused whether ask this question to physics or biology stackexchange. I downloaded a mobile application which claims to repel mosquitoes. This application basically produces sound from ...
13
votes
2answers
1k views

How does a tree trunk sprout and grow after being cut?

After I cut trees into logs and remove the branches in winter, they start growing. They sprout out and grow completely normal looking stems and leaves and maintain them all summer. The sprouts mostly ...
13
votes
1answer
197 views

What is the prehistory of amino acids in cells?

As a followup to Why 20 amino acids instead of 64? and What is the smallest number of amino acids required for life?, I am trying to understand the prehistory of amino acids in cells. All living ...
13
votes
1answer
570 views

What light intensity starts melatonin release in humans?

I'm interested in whether any studies have determined the intensity of light at eye level that starts melatonin release in humans. I know that: melatonin release is suppressed by blue light with ...
13
votes
1answer
3k views

Why do we grow so much hair on our heads compared to our bodies?

I've been wondering about head hair, facial hair in particular. Human males can grow very extensive beards should they choose to not shave - however you do not really see this in our chimpanzee ...
13
votes
2answers
2k 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 ...
13
votes
1answer
79 views

What is the mechanism responsible for the periodicity of hiccups?

Hiccups (singultus) are caused by involuntary spasm of the intercostal muscles and diaphragm, producing a sudden inspiration with associated glottic closure. It seems the neurobiology of the reflex ...
13
votes
1answer
926 views

How does evolution produce complex organs

I've been wondering lately how evolution manages to produce complex organs. It is pretty obvious to me how evolution would select some minor traits like size, resistnce to illness or climate. There is ...
13
votes
1answer
105 views

Does a theory exist for the formation of thylakoid structure?

I'm interested in how the structure of the thylakoid forms into its characteristic highly rugose stacks of grana. What causes the thylakoid to invaginate and self-associate, albeit with what appear to ...
13
votes
1answer
196 views

How straightforward is in vitro compartmentalization?

in vitro compartmentalization (IVC) is one of those technologies that everyone knows about, talks about, but never actual does due to the rather technical difficulties in setting the system up. I was ...
13
votes
1answer
266 views

Do the majority of fish lack scales on their heads?

Based on pictures, it seems to me that a vast majority of fish species that have scales do NOT have scales on their heads. Is that fact true? To make this properly answerable: lets' define a ...
13
votes
1answer
362 views

Looking for a cancer drug target database to guide sequencing of patient tumor DNA

I have a question I would like to pose to the community. I have recently received access to a bench-top ion torrent DNA sequencer. Our idea is to use this machine to sequence the DNA from patient’s ...
12
votes
6answers
1k views

Human evolution: Where *exactly* did the first human come from, whose parents were not?

Layman here. So I have never really quite understood this facet of human evolution, (or any other for that matter), in that, I understand the evolutionary process, but I get lost on the 'border' ...
12
votes
7answers
2k views

Is there a biological mechanism for evolution encoded into our DNA?

Throughout high school, I remember learning about Darwin's theory of evolution as if it were near-fact. But something always seemed wrong about the ideas presented. Survival of the fittest Random ...
12
votes
10answers
915 views

A good book for history of biology/biotechnology for lay people

I have many friends who are interested in Biology and want to know more about the subject in general (like a history of biology, from Darwin's theory, to DNA structure discovery, to the human genome ...
12
votes
5answers
331 views

Is it the case that all changes in phenotype during life are not inheritable?

This came up in a talk with a friend. I wanted to clear this doubt. I've read about it before and did again after her remark (my thoughts didn't change: her concept is Lamarck's, not Darwin's), but ...
12
votes
3answers
2k views

Why is high fructose corn syrup unhealthy?

I understand that high fructose corn syrup was found to have detrimental effects on peoples' health. Why is this so?
12
votes
4answers
306 views

Online repositories of scanning electron microscope photographs?

I have looked at every single Wikimedia commons photo in the category 'scanning electron microscope'. Unfortunately, I could not find any other repositories of such photos, but I would readily look at ...

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