4
votes
1answer
337 views

How can a polar molecule pass through polar channels of proteins in the cell membrane?

To transport a polar molecule through the nonpolar cell membrane, a protein with a polar channel is needed to allow it to diffuse. However, if the molecule is polar and the channel is polar, wouldn't ...
5
votes
2answers
355 views

Can animals like squirrels leave “gifts” or tribute for humans?

I've heard anecdotal reports of squirrels bringing up gifts to a person's house after that person left out food for them. Sounds bizzare and unbelievable, until I actually saw some kind of a nut right ...
4
votes
1answer
147 views

Why do changes in preload not cause changes in end systolic pressure?

I am trying to understand why changes in preload do not cause concomitant changes in end systolic pressure. If you have preload enhancement than this should lead to an increase in cardiac output.....
0
votes
0answers
10 views

How long can the brain function after cutting blood circulation? [duplicate]

If I cut blood circulation from the brain, for how much long can the brain fuction and send commands to the body like the legs?
2
votes
0answers
33 views

How is flagellar movement controlled?

How does a cell control the movement of flagella? Both the rotatory movements and sideways movements helps the cell to move. How are these flagellar movements controlled ? It is through the regulation ...
2
votes
1answer
53 views

Can microorganisms (e.g. bacteria) be damaged or killed by 253,7 nm light?

The question arose in a hospital, where I saw these flyers advertising lamps that emit such light. It was claimed that they can clean the air of microorganisms up to an arbitrary degree. Does anyone ...
20
votes
2answers
1k views

How does RNA transcription determine which half of the DNA to use?

I feel that I might have a complete misunderstanding here. If DNA has two strands, how does the machinery of RNA transcription determine which one to transcribe?
2
votes
0answers
41 views

Birth control hormones in the water? Or not?

This prior question talks about natural estrogen (TL;DR: Months to years): How quickly do estrogens break down in the environment? Ref: http://dx.doi.org/10.1038/485441a A lot of media has said, "...
1
vote
2answers
1k views

What is the function of E-coli bacteria in our stomach?

So, I recently came up with this question. I googled it, but couldn't understand the proper functions of E-coli bacteria. A little definition would be wonderful.
-1
votes
2answers
209 views

If dog's DNA and human's DNA are almost same then can it be said that dogs evolved from humans? [closed]

https://www.youtube.com/watch?v=IbY122CSC5w In this video it is said our DNA matches almost the dog's then it can be also said that dogs evolved from humans. Is it?
8
votes
2answers
2k views

Do we use 100% of our cerebral capacity?

I saw a movie yesterday called Lucy. In this movie, a girl called Lucy absorbs a large amount of CPH4, and her brain capacity slowly increases. So that brings me to my question which is : Do we ...
3
votes
2answers
429 views

Is organ transplantation race dependent?

I watched (IMHO canibalistic) movie "Seven Pounds" where protagonist donated many of his organs to other people and I noticed, that most recipients were black also as protagonist was. Is race really ...
0
votes
0answers
41 views

How to use DRAQ5 and MitoTracker CMXros dyes to stain turtle erythrocytes?

I am working on turtle species and want to use DRAQ5 and MitoTracker CMXRos to stain turtle nucleated erythrocytes. Can anyone suggest me a protocol to carry this stain out? Would the two stains ...
5
votes
2answers
115 views

Specificity of the adaptive lymphocytes

T cells are known for their ability to bind multiple antigens, owing to the degeneracy of the recognition sites on their receptors. [I] When examining the structure of the T cell receptor, we can ...
1
vote
1answer
55 views

Do snRNAs exit the nucleus or not?

In Molecular Biology of The Cell (Alberts, et al., 2015), it lists the various RNAs that are trafficked through the Nuclear Pore Complex (NPC) into the cytoplasm. The list includes snRNAs, but I ...
27
votes
1answer
296 views

Does this recording sound like the pulses emitted by bats?

Out of curiosity, I recorded sounds in an area with lots of bats, hoping to be able to "hear" the bats communicating by lowering the ultrasound to a level down to the frequency which can be heard by a ...
6
votes
1answer
301 views

What happens after the purification step in Hi-C sequencing?

I am a statistician reading an article on Hi-C, and I am trying to better understand one of the steps in the DNA isolation and sequencing process. Since I'm a statistician, please try to avoid too ...
2
votes
1answer
138 views

Is the fixation rate always equal to the mutation rate for neutral alleles?

Background A classical result of population genetic is that the rate of fixation of netreual alleles is the mutation rate $\mu$. The reason is that each generation $PN_e\mu$ mutations enter the ...
1
vote
0answers
29 views

Senescence in space

How is senescence of individual eukaryotic cells and tissues affected by gravity and zero-gravity environments? In other words, can eukaryotic cells live forever in space (given the appropriate ...
2
votes
0answers
48 views

Hydra immortality

Recent research on immortality ha been on an organism named Hydra. I have heard about it being related to some FoxO gene, which has been found in several other organisms but how does telomerase affect ...
-2
votes
1answer
50 views

DNA Replication And Primer [duplicate]

Why does nature rely on RNA primer for the start of DNA Replication? Why not simply use DNA primer and make life simple !
2
votes
1answer
78 views

Introductory book to cell biology

I am studying the human circulatory and respiratory systems to develop tools for automated diagnosis of disease. During the past year, I have read basic books about respiratory physiology, ...
6
votes
2answers
252 views

Are there nerves in the umbilical cord?

I have always imagined that cutting the umbilical cord after birth might be painful. But I have always been confused about who would feel the pain and why. It occurred to me that the mother or the ...
1
vote
0answers
65 views

Why is squeezing not recommended after a needle prick?

I've read some interesting things about the risk of infection after a needle prick (30% - hepatitis B, 1.8% - hepatitis C and 0.3% - HIV), but I've also saw that the local squeezing is not recommended....
0
votes
0answers
48 views

Enzymes and cofactors

About how much % of the human enzymes need cofactors? Like 20%, 30%, or 50% of a cell's enzymes? And how many enzymes work "alone"? This is a general question to figure things out. Do most enzymes ...
9
votes
2answers
2k views

How does life change when you dig deeper?

I've just realized that I have no idea what life / biotopes / soil looks like when you dig deeper than a few meters. I know that in the first meter of soil you can find all sorts of live animals (...
4
votes
1answer
70 views

Are aquatic filter feeders effective at cleaning water to a safe level?

I've been raising Daphnia magna cultures over the last few months as feedstock for freshwater aquarium fish. From my reading, Daphnia feeds on bacteria and single-celled algae, as well as other small ...
21
votes
1answer
297 views

Can someone identify this ant?

This is one of seven ant queens I just collected yesterday morning (2015-09-21 9AM) around home. I live in Hong Kong, at a hillside facing south. The weather was as follows (Hong Kong Observatory ...
1
vote
1answer
35 views

How good is the reproducibility of preclinical models?

Unofficially, biology researchers always complain how frequently fail to replicate results others have achieved. But of course, such failed experiments are underreported. Is there data, or at least ...
1
vote
1answer
128 views

What percentage of people today would likely be descendants a man born 4,000 years ago?

Assuming a particular man was born in southern Mesopotamia, around 4,000 years ago, and was significant involved in a major religion. To what degree (if any) of accuracy could his descendants be ...
3
votes
2answers
57 views

Is there a way to know how many sodium channels are active (conducting) at a given time in the brain?

I was doing some reading about anti-epileptic sodium channel blockers, then wondered how many sodium channels are actually conducting (actively passing ions) at any given time, that is, in an "average,...
1
vote
0answers
37 views

Plasmid with ITPG and pBR322 ori

I'm looking for suggestions as my internet searches aren't turning up much. I'm trying to find a plasmid that has the pBR322 origin, as it's low(ish) copy number and can tolerate large inserts. ...
0
votes
1answer
97 views

How do we perceive acceleration?

Today me and my friend were coming on motor bike and I was sitting opposite direction because I was holding something in my hand (and it was fun :P). When he started bike I felt very high acceleration....
4
votes
0answers
34 views

Why do some Brown Pelicans have orange or reddish parts on their bills?

I am doing research on Brown Pelicans and have photos/descriptions of the breeding and nonbreeding appearances of adults, esp. the California and eastern subspecies here on our southern Pacific, Gulf ...
11
votes
1answer
2k views

How can frogs tolerate freezing while humans cannot?

A wood frog can tolerate the freezing of their blood and other tissues. wiki, news2, but human beings can not. Some people plan to freeze their bodies/brains after death, and some of them have done ...
1
vote
1answer
66 views

Folding of bulliform cells

How do bulliform cells cause a leaf to fold in half when the leaf looses water? Also, how would these bulliform cells be arranged to cause the cell to instead curl up?
1
vote
0answers
54 views

Monocot stele in roots

Why do monocots have eustele in the roots instead of protostele like dicots? I thought the roots don't need the strength of eustele because the roots are supported by the soil. So what is the ...
1
vote
0answers
22 views

How to troubleshoot islet isolation

I have been getting very low yield from islet isolations from rats. My procedure is as follows: Inject the pancreas with 5mL Liberase (1 wunch unit/ml) in HBSS + HEPES through the CBD (decent ...
2
votes
1answer
119 views

Is there a genetic reason explaining the difference of the height of male and female?

The male and female height difference seems to be around 1.08 if all cultures are counted from these stats: https://en.wikipedia.org/wiki/Human_height Can this ratio, 27/25, be explained by genetics ...
4
votes
2answers
267 views

Why are there so many different humans yet chimpanzees are just chimpanzees?

There are two species belonging to the Pan genus (Pan troglodytes and Pan paniscus). That's just two. I mean, humans have changed radically since we split from chimpanzees, we have Australopithecus ...
5
votes
1answer
87 views

What is this tiny thing on the branch

I noticed a tiny spot with weird shape on the shoot of a plant (Variegata), and there are many others on other branches. I wonder what is it, this is a cropped picture of it, Thank you!
3
votes
1answer
65 views

Virus-to-virus gene transfer via “sequences integrated into a common host organism”

From "Risks from GMOs due to Horizontal Gene Transfer", by Paul Keese: In addition to direct HGT between organisms as depicted in Figure 1, forms of indirect HGT have been observed, which involve ...
5
votes
2answers
483 views

Evolution of endosymbionts?

Mitochondria and plastids in eukaryotes evolved through a process of endosymbiosis. How does an event like a eukaryote engulfing a bacteria, become a part of the genome? Some of these primitive ...
1
vote
0answers
51 views

Calculating the recombination factor of four point genetic cross?

So, I'm trying to work out the recombination factor (RF) from this set of data: Which shows the 16 phenotypes of progeny of a cross of Saccharomyces cerevisiae yeast. I know how to go about a three ...
2
votes
3answers
961 views

Do we consume dna, proteins of other organisms?

When we eat raw meat, e.g. chicken or fish, we are actually consuming the DNA, proteins etc. which are present in their cells. Wouldn't this affect our cell functions as this DNA might enter our ...
7
votes
1answer
364 views

How does a neuron change as you learn?

I am currently taking a course called "Introduction to Machine Learning with ENCOG 3", and I have a question about how well the Artificial Intelligence (AI) algorithm for a "neural network" ...
3
votes
1answer
153 views

How do eukaryotes terminate transcription? (clarification on Campbell Biology)

I'm having trouble understanding how eukaryotes terminate transcription. Studying Campbell Biology (pg. 342, 10th ed.), I read: In eukaryotes, RNA polymerase II transcribes the polyadenylation ...
3
votes
2answers
228 views

Why do veins undergo vasoconstriction during physical activity?

How would this help increase blood circulation?
1
vote
1answer
30 views

In vitro virus assembly

Are researchers able to assemble viruses in vitro? For example, I imagine that a phage display library may be generated by throwing in a test tube the capsid proteins (or what have you) along with ...
5
votes
1answer
159 views

The replicator equation vs the Lotka-Volterra equation

Background The replicator equation with $n$ strategies is given by the differential equation: \begin{equation} \dot x_{i} = x_{i} \left( \sum_{j=1}^{n} a_{ij}x_{j} - \phi \right) \qquad i = 1, \...

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