4
votes
0answers
85 views

What controls leaf senescence in deciduous tree species, and how can I predict it?

If I want to predict litterfall, what data do I need to collect, and what statistical model might I use? For example, I might use the following coding to record phenological stage every other day, or ...
8
votes
2answers
6k views

Agarose vs agar? Why do DNA gels use agarose only and how do you obtain agarose from agar?

Agar is a relatively cheap substance from red algae. And it contains a saccharide agarose as well as a small amount of pectin. Agar is used for culture plates as is, but for DNA gels a grade of ...
2
votes
1answer
964 views

Perception of artificial light - flickering

I noticed something strange a couple of years ago. I was walking down the street at night, when it struck me that the street lights were flickering. But, when I turned to take a direct look at the ...
2
votes
1answer
3k views

How does a thymidine block halt DNA synthesis?

The best I've been able to find is that there's a feedback mechanism, but what is this feedback, and how does the mechanism work? If it's just that the concentration of thymidine is too high, why ...
1
vote
1answer
53 views

Are there any neurotransmitters that trigger all neurons?

I'm reading into the basics of the nervous system, and am intrigued by neurotransmitters. I understand that certain neurotransmitters can trigger more than one neuron type, and may be used as ...
4
votes
2answers
109 views

Is there a strong reason to be sceptical about the “cured HIV patient” being reported by mainstream media?

There's a story going round the news about a baby that was, apparently, cured of HIV using a cocktail of drugs at an early age. The story piqued my interest, but details seem scarce. One of the main ...
7
votes
1answer
61k views

What causes random long white body hairs?

I'm sure many of you have experienced this - you scratch your back or brush your hand over your arm and find a ridiculously long thin white hair, sometimes as long as 3 or 4 inches. I know a few ...
2
votes
2answers
168 views

What chemicals can be detected from one's sweat?

This question came to mind after reading this article. The article speaks of inducing sweating to determine by a roundabout fashion the amount of salt therein. I'm no medic but I find myself wondering ...
0
votes
1answer
389 views

Does one neurotransmitter travel all the way through the nervous system?

Nerve impulses of course go really fast, but the neurotransmitters have to travel through millions of nerves, so how can it go that fast? Is it a sort of relay with lots of neurotransmitters taking ...
1
vote
1answer
1k views

Serotonin - Does being aroused make you sleepy?

My Psychology text book says Serotonin causes "Sleep, arousal levels and emotion" Does this really mean that when you are being aroused, Serotonin is released, which in turn makes you sleepy? If so, ...
1
vote
2answers
67 views

Is it possible to do chip-seq on a specfic region?

Is it possible to do Chip-Seq on specific region of the genome. The idea is to enrich before the sequencing step to have more sensitivity.
4
votes
2answers
3k views

How can I resuspend a cell pellet without harming the bacteria?

When using a preculture with Ampicillin in my protein expression, I have to get rid of the preculture medium to avoid carrying over too much beta-lactamases that will destroy the ampicillin in the ...
2
votes
1answer
69 views

Formation of ammonia from air and moisture

On extended bicycle trips I sometimes slept under a plastic sheet, which helped with mosquitoes on hot nights. But there was a noticeable build-up of ammonia which made this almost impossible for more ...
6
votes
1answer
557 views

Exercise causes number of cell divisions to approach Hayflick limit faster? And hence shorten life expectancy?

A world class athlete spends a lot of time performing intense exercises. Correct me if I'm wrong, but I assume that these intense exercises causes significant damage to the athlete's cells, but with ...
1
vote
2answers
359 views

By what mechanism does penicillin resistance usually develop in Streptococcus pneumoniae?

There are three mechanisms: prevention of the interaction between antibiotic and the target PBP; modification of the binding of the antibiotic to the PBP; hydrolysis of the antibiotic by a ...
3
votes
1answer
41 views

What Makes A Pet Hypoallergenic

I know you can purchase dog and cat breeds that are hypoallergenic so those who are prone to pet allergies will have reduced allergies or none at all. These breeds are specifically bred for that ...
7
votes
1answer
124 views

What causes XYY Syndrome?

It's obvious how a misdisjunction can result in klinefelter's syndrome (XXY) but I don't see how this can result in XYY syndrome. Your parents have a collective total of only one Y chromosome so how ...
1
vote
1answer
67 views

Do repeated freeze-thaw strip nutrition from vegetables/food?

For some inexplicable reason from the ladies in my extended family (even friends!) seem to believe that vegetables/food should be subjected to as few freeze/thaw cycles as possible. The rationale put ...
2
votes
1answer
257 views

How does this diagram illustrate carbon cycling in lakes?

Could someone please explain the following process to me: This process refers to carbon cycling in lakes and is described in the context of $CO_2$ flux from lakes into the atmosphere. GPP is gross ...
2
votes
0answers
156 views

How much food can an average person eat, and which animal is that equivalent to? [closed]

When the average person overeats, how much food can he eat in a day? Which animal's average meal would that be equivalent to? When documentaries are talking about animals feed, they usually say ...
0
votes
1answer
243 views

A good textbook on Neuroscience [closed]

I want to start learning Neuroscience. Can someone give me an advice about a nice textbook for beginners? I'm particularly interested in the application of Neuroscience in programming and AI ...
8
votes
2answers
3k views

What makes a gene dominant or recessive

We all carry two copies of each gene (outside of male sex chromosomes). If the two differ from each other often one is dominant and one recessive. How does this mechanism work on a molecular level? ...
1
vote
2answers
126 views

Plants without bacteria? is it theoretically possible?

I know from school, that all live on the Earth need bacteria as low-level "machines" that break down/extract/convert/produce chemical elements and combinations, other high-level organisms needed. But ...
3
votes
1answer
77 views

Can I use PCR buffer instead of cDNA synthesis buffer?

I am using Fermentase First strand cDNA synthesis kit but its buffer is over. I need to work today but I have not access to any sorce currently. I have PCR buffer in the lab. Can I use PCR buffer ...
4
votes
2answers
393 views

Question about cell signaling pathways (RTK, Jak-Stat, SMAD, etc)

I am in an embryology course right now and we've just started covering cell-cell communication in development. We were talking about the roles of the various cadherins and their discoveries but we got ...
1
vote
1answer
44 views

Can Palisade Cells Survive Independently?

I have been intrigued by this question. Can palisade cells survive independently from its parent plant in a chemical environment? For example, if we were to separate a palisade cell from a plant and ...
0
votes
1answer
28 views

Multiplication to formalize Microbiological Processes

I am not from the field, but have a question regarding modeling in biology: I know that some processes can be modeled with the mathematical multiplication operation, and wondered if anyone could ...
6
votes
2answers
200 views

Can forensic DNA analysis be used to generate a visual approximation of a suspect?

In light of the current US supreme court case, I'm curious if enough information can be teased out of a DNA sample to get a "reasonable" approximation of the suspect (never mind the legality). I ...
1
vote
1answer
71 views

Are there any studies of epigenetic difference between twins during their lifespan?

Are there any studies of epigenetic difference between twins during their lifespan ? I ask because I wonder if there exist phases during lifespan, when environmental factors plays major role ...
0
votes
1answer
48 views

How do amino acids become attached to tRNA?

Is there a protein that catalyzes this or does it happen spontaneously? In which part of the cell does this happen?
6
votes
4answers
463 views

Chromosomes are of different size but why do all chromosomes have similar GC percentage?

When I browsed NCBI I saw a pattern: even if the chromosome sizes, number of genes, and number of proteins are different, GC% in chromosomes tend to be similar. The examples are linked below. Yeast, ...
1
vote
2answers
191 views

Does the Urea Cycle exist in invertebrates?

Do invertebrates (like Drosophila and C.elegans) have a urea cycle?
1
vote
1answer
36 views

Can the sulphur content of biological material be reliably calculated from fat, fibre and protein contents (Weender Analysis)?

An often-used analysis of feedstocks for lifestocks is the Weender analysis, which basically divides the volatile solid content into fats, fibre and protein, as well as N-free matter. I found no ...
-4
votes
2answers
108 views

Specific enzyme for C. elegans [closed]

We are looking for an enzyme that appears in C. elegans but isn't common for: human, Drosophila or mouse. We need it for a little research project, thanks for your help!
3
votes
1answer
464 views

Why re-label the strand ends in 3' DNA labelling?

I have a problem with a molecular biology question; I don’t understand how DNA 3’ labelling works. I took a diagram from my lesson and tried to understand with it; this is what I understood. If I’m ...
6
votes
2answers
797 views

How long can I store autoclaved disposables and reagents?

I want to stock up on autoclaved disposables, such as Eppendorf tubes, pasteur pipettes etc., and some buffers. If I don't open the container after autoclaving, how long can I store autoclaved ...
3
votes
2answers
513 views

Why does Glutamine have the symbol Q?

Spent a half hour googling this and the best I could find was this: Now for some rhymes: Arginine = R. R we having fun yet? Asparagine = N The kNights of Ne say "Ne". Glutamine is a cute ...
4
votes
1answer
122 views

Effect of doubling volumes of PCR reagents

We ran PCR with a positive control and two lanes of sample. We used the same sample, but in one PCR mixture we used a total volume of 50μL (25μL Taq, 5μL forward&reverse primer each, ...
4
votes
1answer
129 views

What is benjamini

I was doing some gene expression analysis using this tool http://david.abcc.ncifcrf.gov/summary.jsp. However, I have a confusion about what benjamini is. I fed it some gene list and it gave me some ...
1
vote
1answer
64 views

Can we use Acetyl Phosphate instead of Acetyl CoA in TCA?

I am thinking Citric Acid cycle and activation of the end parts of Acetyl and alfa-ketoglutarate. Let's consider only now Acetyl to make things simpler. I have tried to explain the thing by symmetry ...
5
votes
2answers
587 views

Why did the urinary bladder evolve?

Sure it's convenient to decide when to urinate but not essential for survival or reproduction, as I understand. But just convenience is not a drive for evolution. Does the bladder serve any essential ...
7
votes
2answers
271 views

Can spider silk be synthesized for 3D printing with spider silk?

With the recent rise in 3D printing, I keep hearing about more novel ways to use the technology: cell 3D printing, liquid aluminum or plastic 3D printing. For example, this Ted talk deals with ...
3
votes
1answer
118 views

Why seeds won't sprout given excess water?

What would cause a seed to not sprout despite showing signs of germination given excess water? Oxygen, temperature, and light were sufficient for germination and sprouting in seeds of a slightly ...
2
votes
2answers
119 views

Lactose Intolerance

What nutrition is given to infants who are lactose intolerant? I understand, in today's day and that age we have non-lactose formula milk, but what happened, before lactose-free milk was created, to ...
4
votes
1answer
60 views

HSL Lightness vs Eye sensitivity

In a monochromatic spectrum, is the human eye equally able to distinguish between lighter colors just as it is in distinguishing between darker colors? I mean is there really a linear relationship ...
1
vote
0answers
27 views

Can Opioids Attenuate some of the symptoms of Psychosis?

Can Opioids Attenuate some of the symptoms of Psychosis? I ask because there's a dead link on the Wikipedia page http://en.wikipedia.org/wiki/Opioid_dependence#Causes that's meant to support the ...
4
votes
1answer
448 views

Are there predators evolved to eat puffer fish?

Puffer fish is known for having a anti-predation defense mechanism of having toxin-exuding spikes. Are there predators which evolved specifically to prey on puffer fish? (presumably, by evolving ...
4
votes
2answers
182 views

Gas from bacteria that's not methane

Is gas produced by bacteria always mainly methane? Or, are there bacteria out there that produce some biogas composed mainly of hydrogen, natural gas, propane, butane?
6
votes
1answer
193 views

How was the first ribosome theorized to have been made?

Seeing as ribosomes are what help perform the act of translation itself, and the blueprints for they themselves are in nucleotide sequences, how was the first ribosome theorized to have been made? ...
3
votes
1answer
1k views

How much does donating blood affect the amount of oxygen in your blood stream at high altitude?

I am a regular blood donor and I am also a skydiver. We normally go to around 13,000 feet AGL (above ground level). Depending on how high above sea level the ground is, altitudes could be as high as ...

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