3
votes
1answer
145 views

By what mechanism is Streptococcus bovis acting as a risk factor for colorectal cancer?

Streptococcus bovis bacteremia/endocarditis is considered a risk factor for colorectal cancer. What pathophysiological mechanism may link the two together?
0
votes
1answer
586 views

Writing methods section on PCR amplication in a paper

Considering that I am writing a paper for a journal, could the following phrase be understood? or should I put the 'step-by-step' way by giving numbers? PCR Amplification and sequencing PCR ...
1
vote
1answer
56 views

What's seen when stress echocardiography shows ischaemia? Can this happen without angina?

What can be seen on the screen when stress echocardiography (a pair of heart ultrasounds before and after exercise) suggests ischaemia? Can this happen without chest pain? Illustration from ...
2
votes
3answers
1k views

Primer design for Gibson assembly

I'm trying to design a primer for Gibson assembly. My gene of interest is on a plasmid, and I want to copy that gene, and put it into a different plasmid. I am unsure how to design my primers for ...
3
votes
3answers
532 views

Why do neurones use chemical signalling at synaptic junctions?

Problem. When a neurone fires, it sends an electrical signal that jumps down the axon via the nodes of Ranvier very rapidly. At a synaptic junction, chemical brownian diffusion signalling with ...
3
votes
1answer
931 views

What is the purpose of Y-shaped adapters in Illumina sequencing?

Y adapters different sequences to be annealed to the 5' and 3' ends of each molecule in a library. The arms of the Y are unique, and the middle part, connected to the DNA fragment, is complementary. ...
1
vote
2answers
487 views

General undergraduate zoology textbook recommendation?

I am very interested in zoology,and I want to study zoology in my spare time. Any undergraduate level zoology text book recommendation?
3
votes
3answers
989 views

Knockdown of long noncoding RNA (lncRNA) - how is it done?

I don't work at the wet lab and don't know all the details about the knockdown techniques. My question is: How lncRNA knockdown is done? For example - you have lncRNA that is functional in the ...
0
votes
1answer
99 views

Are humans more aggressive during a full moon? [closed]

Is it true that we are more agressive during the night when there is a full moon? If true, could this be a remnant from times where we needed to hunt for our food and so could see more at night when ...
5
votes
1answer
162 views

What effect do oligosaccharides, like those found in legumes, have on the composition of intestinal flora in humans and if so how so?

I know that intestinal flora metabolising oligosaccharides, like those found in legumes, is the cause for the well known fact that legumes cause flatulence, but does an oligosaccharide-rich intestine ...
0
votes
0answers
76 views

What material is recommended for autoradiography cassettes when working with 32P? [on hold]

So, during radiation safety training, much hullabaloo is made regarding how the high energy beta emitted by 32P produces Bremsstrahlung radiation when striking a high Z shielding material. As such, ...
5
votes
1answer
469 views

Why does it hurt more when you touch a nerve directly?

I am not a biologist nor know much about biology (so please explain in layman's terms) however I have always been curious as to why this is. What causes the difference in pain between touching an ...
2
votes
1answer
243 views

How is transport of glucose into prokaryotic cells different from transport into eukaryotic cells?

I was reading page 92 of Fundamentals of Microbiology, 4th edition, which states In facilitated diffusion, the substance (glucose, for example) to be transported combines with a plasma membrane ...
2
votes
1answer
39 views

What are ways to compare the “costs” and “gains” of food production systems?

I'm looking for methodologies to compare the costs a food production requires with the gains it delivers (not in economic terms). I'm aware of energy returned on investment. Are there other methods ...
9
votes
3answers
706 views

How are our senses dimmed during sleep?

Our senses are not as sensitive during sleep compared to wake. There is an arousal threshold during sleep that only when it is overcome will it wake a person up. My question is how is this arousal ...
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 ...
2
votes
1answer
419 views

Why is the blood pressure in the superior vena cava during inhalation less than during the exhalation?

For further investigation into the progress of the blood pressure, we will measure a patient's blood pressure in the superior vena cava measured during inhalation and during an exhalation. His heart ...
4
votes
1answer
114 views

What are some examples of scaling laws in biology?

I've seen that metabolic rate scales logarithmically as function of mass for many animals over an extremely large span of parameters. What other scaling laws exist at the individual level?
2
votes
2answers
381 views

Why is a slow worm not considered a snake?

Slow worms are considered lizards as opposed to snakes, both are reptiles. Now I get that there are traits that distinguish them (eye lids, ears ...). But snake species themselves vary already quite a ...
6
votes
4answers
501 views

If Evolution Is In Progress, Why Fight Extinction?

Natural selection is a central tenet of evolution. However, most biologists seem determined to prevent the extinction of the species that have been selected against. Why is this? Preservation of ...
3
votes
0answers
88 views

Why do ants dig surface paths?

A few days ago I observed a corridor built and used by ants that went over a path in fields: Why do they build it? It seems it doesn't bring any considerable protection from the surrounding ...
2
votes
1answer
807 views

Why is Sanger sequencing inferior for detecting SNPs in cancer cells?

I am familiar with Sanger sequencing, but at the level of an undergraduate. A lecturer of mine tried to describe Sanger sequencing as losing the sequence information in noise when used to detect ...
0
votes
1answer
66 views

SNPs mapping into protein

Starting a new project on protein-protein interactions and SNP analysis tool development. I would like to ask how does SNPs is mapped into protein? What does mapping means?
2
votes
1answer
43 views

Storing Apples at 30F?

This article about storing apples for the winter says: You do not want the apples' temperature to fall below 30°F (-1.1°C), however, because that will make them freeze and turn to mush when ...
4
votes
1answer
458 views

Breeding laboratory mice with cancer; how does this work?

It has recently been brought to my attention that live laboratory mice with specific cancer strains can be readily purchased for medical research. For example, the Jackson Laboratory sells mice with ...
1
vote
1answer
384 views

What is solid-phase bridge amplification?

During Illumina sequencing there is a step called bridge amplification by which DNA is amplified by isothermal enzymes. What is this stage, and how does it work?
5
votes
2answers
5k views

What's the difference between shotgun sequencing and clone based sequencing?

What are the main differences between shotgun sequencing and clone based sequencing?
7
votes
1answer
685 views

Does the human ear adapt to noise levels?

I have noticed lately that if I go to sleep, when I have my radio running, it is on lowest volume, I still consider it kind of loud. In the morning, when being on the edge of waking up, I hear the ...
1
vote
1answer
51 views

“Oblong to Allantoids” … Is it valid?

I read on the text book: The characteristic of Dinemasporium are: superficial, cupulate to Discoid conidiomata with brown satae, Phialid conidiogenous cells that give rise to hyaline, oblong to ...
1
vote
1answer
81 views

By what mechanism does elevated homocysteine level accelerate thrombin formation?

It has been stated that elevated homocysteine level accelerates thrombin formation. By what mechanism does this happen?
2
votes
2answers
212 views

By what mechanism does elevated homocysteine level cause endothelial dysfunction and damage?

It has been stated that elevated homocysteine level causes endothelial dysfunction and damage. By what mechanism does this happen? Why is it the endothel where elevated homocysteine causes problems? ...
0
votes
1answer
58 views

Does anyone know what marsupial this is? [closed]

I know what this is a marsupial, but i'm not quite sure which one. Any thoughts?
2
votes
1answer
52 views

How can I view modENCODE data faster?

I am trying to view several data tracks in the modENCODE GBrowse genomic browser. However, the site is so slow, it is practically unworkable. Is there a faster way to explore the data?
4
votes
1answer
307 views

How do sharks and other fish conserve and gain water in marine environments?

With the osmolarity of the average vertebrate being around 300mOsml, and salt water having an osmolarity of 1000mOsml, why does the water from the shark not leave to the salt water around it? I ...
3
votes
1answer
860 views

Is it possible for a person to become “reinfected” with the same strain of a virus?

If a person contracts a virus, viral conjunctivitis for example, is it possible for the individual to become "reinfected" with the exact same strain of the virus once the person has it treated and the ...
1
vote
1answer
50 views

Are there neuronal firing artifacts produced by head movement?

I'm experimenting with a consumer-grade ElectroEncephaloGram (EEG) sensor and have created the image below using the device. Because the sensor on the device does not use a suction cup, there are a ...
2
votes
1answer
90 views

Is RGB diode lighting okay for the eyes?

Is a light source giving off light composed of red, green and blue lights harmful to the eyes? Does it lack any important qualities that other artificial light sources, such incandescent lamps or ...
1
vote
2answers
202 views

Is it possible to print humans?

According to this news, scientists can use stem cells to print objects. So say theoretically, is there any possibility to print human beings?
2
votes
2answers
290 views

DNA replication Okazaki fragments

I understand multiple origin bubbles; DNA polymerase only synthesizes DNA from 5' to 3' and all that. But what I don't understand is why it has to be in fragments. Yes, DNA is anti parallel, and so ...
2
votes
1answer
317 views

Will lipid molecules 'flip-flop' over a membrane without the use of an enzyme?

All of the references to this I can find refer to enzymes like Flippase making it 'easier' or 'more likely' that the translocation will occur, rather than actually make it possible. The following is ...
9
votes
2answers
1k views

What is the evolutionary reason behind the fragility of teeth?

Almost all organs in the human body have a rather large threshold within which the organ or tissue is capable of repairing itself using materials supplied by the body, whether it's made from organic ...
2
votes
1answer
111 views

Why is elevated homocysteine considered a risk factor for angina?

Elevated homocysteine levels are listed among risk factors for angina. How is homocysteine related to the heart? Or the coronary arteries? How do these relationships make it a risk factor for angina? ...
2
votes
2answers
45 views

Can stress echocardiography show coronary blood flow difference before and after exercise?

Stress echocardiography means a pair of cardiac ultrasound imaging examinations, before and after exercise. I assume that coronary blood flow is increased after exercise. Is cardiac ultrasound ...
2
votes
1answer
310 views

By what mechanism does an obstructed bile duct cause excess fat in the stool?

By what mechanism does an obstructed bile duct (for example gallstones) cause steatorrhoea (excess fat in the stool)?
5
votes
1answer
372 views

What could account for an apparent loss of mass at death?

An interesting tidbit floating around the internet these days is that Dr. Duncan MacDougall apparently weighed people shortly before and after death, and found an average of a 21 gram discrepancy, to ...
3
votes
0answers
38 views

Can I purify polyhydroxyalkanoates by heating the cells extensively?

Traditional methods of purifying polyhydroxyalkanoates (PHAs) and other bioplastics made by bacteria involve washing the cells with harsh chemicals or strong bases.I'm interested in maintaining the ...
4
votes
1answer
65 views

How can I save bacillus strains on filter paper without an -80 degree freezer?

I want to save my bacillus strains but I don't have access to a -80 degree freezer. What are possible alternatives?
5
votes
2answers
168 views

How does a pinched nerve cause pain (at the molecular level)?

Is this due to pressure differentials in the surrounding tissue? (Is it possible to have a pinched nerve without compression of the surrounding tissues, and does this cause pain?) What are the ...
9
votes
2answers
2k views

Why is saltatory conduction faster than continuous conduction?

How does spacing apart sodium and potassium channels allow the action potential to travel faster down the axon? This is the reason always cited for saltatory conduction and myelination, but my mental ...
4
votes
4answers
25k views

How long human can survive with just drinking water everyday

Can humans live without eating food, just by drinking water? How long can we survive just by drinking water everyday?

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