41
votes
3answers
4k views

Why does cracking a joint make noise?

What causes the noise when you crack a joint? Is joint cracking harmful?
0
votes
1answer
3k views

How do ants know where they are going without eyes? [closed]

I know that ants have some sense of direction, but what is the physiology behind this sense?
2
votes
1answer
201 views

Can foxes move their ears independently?

I've read that dogs can do move their ears independently, i.e., point one ear in the direction of a sound without having to point the other one at the same time. Is this a common trait with other ...
3
votes
1answer
441 views

How does sucrose protect bacterial cells in lysozyme solutions?

I have a microbiology question. When we put bacterial cells in sucrose solution with concentration higher than 0.5M we observe plasmolysis - the cytoplasmic membrane detaches from the cell wall due ...
3
votes
1answer
51 views

How much divergence would be needed for classifications as astrobiology?

It is possible that life has invaded mars or the moon by way of probes rovers and other man made tech. How many years or generations of sequential and phenotypical diverge would be necessary to ...
2
votes
2answers
567 views

MOL2 to PDBQT conversion via OpenBabel and MGLTools removes hydrogen atoms

I am trying to convert a MOL2 file (includes partial charges and hydrogen atoms) into a PDBQT file for re-scoring in AutoDock Vina. However, both approaches that I tried don't keep the hydrogen atoms ...
27
votes
1answer
3k views

Is humans' height ideal?

More or less we humans are around 1.70 meters tall. My question is, would it be possible to scale us? that is, is it in principle possible having humans 1 cm tall, or 10 meters tall or is there some ...
1
vote
1answer
382 views

Has anyone used Crispr/Cas to induce a knock-in in MEF cells?

Does anyone have experience with the crispr/cas9 platform performed on MEF? Or does anyone recall any relevent articles? Thanks
5
votes
4answers
10k views

Can nosebleeds cause death?

Can epistaxis or nosebleeds be a of cause death?
3
votes
1answer
267 views

Identify this Harvestman

I spotted this guy in Switzerland. It's clearly an Opilione (Harvestman), but I really know nearly enough about this diverse group to be able to identify the species. Sorry, I didn't think to ...
6
votes
1answer
197 views

Location of nucleotide synthesis and transport

I couldn't find this question directly asked so I thought I would ask it In Fundamentals of Biochemistry 3e (Voet et al), it has a small small little comment about pyrimidine synthesis: (In a diagram ...
3
votes
1answer
138 views

Horizontal gene transfer versus convergent evolution

There are several often noted examples of convergent evolution (eyes, bat/bird wing evolution etc.) How do we rule out horizontal gene transfer in these cases?
1
vote
1answer
287 views

Can I identify this black ant queen?

I have an ant queen in a jar. This is what she looks like: Because I'm planning to start an artificial ant nest, I'd like to learn something about that specific species of ant. This particular ...
5
votes
1answer
182 views

High frequency human genetic oscillators?

The most well studied genetic oscillators in human genomes are involved in regulating the circadian clock (which operates on an approximately 24-hour cycle) and cell cycle activity (with single cycles ...
5
votes
2answers
130 views

What are some atypical examples of positive transcriptional cooperativity?

Cooperativity in gene expression is an important feature of many regulatory networks. Described using the Hill function, the most common example is a transcription factor (TF) that when bound to its ...
5
votes
1answer
238 views

Why does ant queen keep the eggs out of her hive?

I have captured an ant queen and now I'm trying to create an artificial ant nest. I have noticed that though she has dug a hole to hide in, she keeps the eggs out of it unless she feels that they ...
4
votes
0answers
113 views

Why are Mammals are unable to produce Essential Fatty Acids?

Why do 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?
3
votes
1answer
41 views

How to make sure a stem cell culture is cancer free?

Say I take a blood sample from an adult, extract the white cells and apply to them the process described in <this article>. Assuming this actually turns the adult white cells into stem cells, which ...
2
votes
1answer
147 views

To what extent do domestic animals understand language?

Note: Please tell me to re-post this in Cogsci or pets if this doesn't belong here. Hello All, I want to know how dogs or other domesticated animals differentiate between normal chat and a command. ...
2
votes
3answers
135 views

How did the horned lizard evolve?

It's a lizard that has the ability to burst blood vessels in it's eyes and shoot blood as self defense. How can this behavior be explained evolutionary? Wouldn't it mean that there had to be some ...
3
votes
1answer
360 views

Are there any air-plants with parts that are edible for humans?

Are any air plants (Tillansia sp.) safe for humans to eat? I haven't been able to find whether or not there are. Pineapple is in the same family (Bromeliaceae), but isn't an air plant.
3
votes
1answer
218 views

How much energy is required to blind someone?

As I understand the ravages of sunlight upon the (human) eye; the cause of ocular damage and blindness is too much energy delivered to the cones and rods that ultimately make up our eyes; so the ...
1
vote
1answer
181 views

Schedules of mating for men

It’s simple deductive logic to follow that for a species to survive it must provide it’s offspring with the best possible conditions to ensure it’s survival – either that or to reproduce in such ...
2
votes
1answer
396 views

What is this black insect (wasp-like?) South America?

I live in the Pacific coast of South America. Seems to have two wings, like a wasp's. The "tail" is a bit bulky but is only connected to the rest of the body by a thin part. It's black overall. The ...
1
vote
1answer
147 views

Question about the DNA glycosylase enzyme assay/formamide gel loading buffer

Often for the DNA glycosylase enzyme assay we can see that the DNA glycosylase is incubated with oligonucleotide in 37C and then reaction is stopped by addition of formamide gel loading buffer (80% ...
6
votes
1answer
89 views

How does the frequency of a visual stimulus affect the steady-state visually evoked potential?

I want to design a project for EEG signal processing. In my research I found the concept of SSVEP. SSVEPs represent the electrical activity of the brain as measured via EEG, and are evoked by visual ...
3
votes
3answers
149 views

More entropy: Atom or Macromolecule? [closed]

A question that appeared on my last exam was : Which of the following has greater entropy A) An atom B) A macromolecule The question doesn't specify anything else(i.e. type/size of atom or ...
14
votes
3answers
9k views

Supercomputer Vs Human Brain

With supercomputers doing calculation in petaflops ($10^{15}$ Calculations per Second), have we crossed the speed of Human Brain?
4
votes
1answer
2k views

how many abdominal sclerites would be there in a cockroach

Every tegmina of a cockroach has Sclerites which are homologous to the bones of humans. Every abdominal segment of cockroach consists of two lateral sclerite plates called pleura along with a dorsal ...
23
votes
5answers
2k views

Why are there species instead of a continuum of various animals?

As I understand it, various animal traits have to evolve gradually, but what happens to the species that are "neither here nor there"? To put it differently, if a species evolved from another, it did ...
2
votes
3answers
336 views

Where are the evolutionary “inbetweeners”? [closed]

The problem I've always had with evolution is the actual lack of variation between animals. More specifically, the lack of observable gradual change between species. Take for example the hammerhead ...
5
votes
1answer
69 views

Does fasting improves immunity?

I have heard that fasting causes regeneration of memory cells(B- and T-lymphocytes) thereby improving immunity.Is this true? If yes, how?
6
votes
1answer
80 views

How can I tell if regulation is at the transcriptional or translational level?

I was reading a paper, http://www.pnas.org/content/109/8/E471.short, where the authors claim that (e475) Translation of the TfR (Transferrin Receptor) is regulated through sequences in the 3′ and ...
2
votes
0answers
2k views

Why does skin sometimes suddenly itch when you stretch it? [closed]

Sometimes, when I bend over, areas of my skin like my back can suddenly itch quite intensely. Sometimes it may be another part of my body and the pattern seems to be a part of the skin organ that is ...
3
votes
2answers
423 views

How to use Autodock just for (re)scoring

I have some protein-ligand complexed that I have been docking with some other software and just want to use Autodock to evaluate those complexes. So, basically I just want to use it as a scoring ...
3
votes
0answers
93 views

Why doesn't honey spoil quickly? [duplicate]

Why is it that honey can last for decades and not spoil like other foods? Is there any chemical in honey which gives rise to this amazing feat?
7
votes
2answers
186 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 ...
4
votes
1answer
204 views

Start studying mathematical biology from basics

I am really passionate about theoretical and quantitative biology and I would like to build my future career around this topic. I've just got my bachelor's degree in biology (ecology) but scince I've ...
5
votes
1answer
206 views

Lost Ability to Regenerate Body Parts during the Transition from Amphibians to Mammals

Why have higher-order animals lost the ability to regenerate body parts during evolution? Wouldn't it be better for survival? What is the evolutionary theory behind it?
1
vote
1answer
1k views

RNeasy Mini Kit low 260/230 ratio — can I purify this RNA for further use?

I used Qiagen's RNeasy Mini Kit to isolate RNA from 5*10^5 C28/I2 (immortalized human chondrocytes). However, my yield is low (~25 ng/ul), but my 260/280 ratio is great (~2.3), and my 260/230 ratio is ...
6
votes
0answers
70 views

How to measure Na/K channel activation at the membrane level?

Assume that there are two different signals occurring on the ECG - during depolarization and repolarization in the standard ECG. I was advised not to use the standard ECG in measuring the exact ...
2
votes
1answer
151 views

Inductance in cell

In an animal cell, especially neuron and in particular its axon, while there is electrical resistance and capacitance mechanism in the cell, which play essential roles in the cable theory model of ...
2
votes
1answer
83 views

What is the role of lamellar bodies in lung cells?

Lamellar bodies have been found to be secreted in lung cells many of their associated proteins have been identified. What is the current consensus or research on the function that these lamellar ...
0
votes
2answers
132 views

How can you explain the origin of life out of nonliving matter (abiogenesis)? [closed]

According to biochemist Robert Shapiro, the "primordial soup" theory is as follows: Early Earth had a chemically reducing atmosphere. This atmosphere, exposed to energy in various forms, produced ...
0
votes
2answers
70 views

Is there any possible way that hybrids can mate?

I'm writing a book, and a a portion of it involves a society of humanzees. Now, is there any plausible way that a hybrid (such as a humanzee) could procreate either with one another, or with their ...
2
votes
1answer
80 views

When a thought 'crosses your mind', does it literally cross between left and right cerebral hemispheres?

I've heard that part of cognitive processing is information passing between left and right cerebral hemispheres. This is what happens in the Cerebral Cortex which is divided into two hemispheres, ...
5
votes
2answers
497 views

Effect of steroid hormone on specific cells?

As steroid hormones can pass through the plasma membrane by simple diffusion because they are lipid derived hormones, it means that they are capable of passing through every cell of our body, BUT why ...
4
votes
2answers
762 views

Is there a durable surface that ants can't pass?

I'm looking for a surface, that will be impassable for ant's yet not poisonous or easily decaying. One idea is water - they really can't cross that. But water easily dries and is quite uncomfortable. ...
4
votes
1answer
191 views

Can you measure ECG from a single location?

I want to make a DIY bracelet to measure my ECG. All I need is the interbeat interval. Can I design a bracelet on one arm only, with two electrodes slightly spaced from one another, and figure out ...
7
votes
1answer
334 views

How did these apples grow together?

I came through this pic while scrolling through facebook, and it was a bit strange to me. As far as I know apples have a corymbose type of inflorescence, in which a single pedicel ends in a single ...

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