2
votes
1answer
48 views

How to measure quality and quantity of DNA?

I would like to mesure DNA. I quantify the concentration with Qubit fluorometer, but I would like to know also quality of DNA. I try BioAnalyzer (Agilent),but without success. Bioanalyzer measure DNA ...
2
votes
1answer
67 views

dopamine paradox in Schizophrenia

If there is more dopamine action in the mesocortical pathway in Schizophrenia, then the patients should always be in euphoric state. But instead patient lacks motivation and don't want pleasure. Why?
3
votes
1answer
54 views

How do I get a brighter DNA bands

I've been trying to a good contrast for my DNA bands, however I haven't been so successful. I've been running the ladders only to make sure I get a good contrast before further experimentation. I ...
1
vote
1answer
20 views

How can a YAC be screened against a cDNA library and a cosmid library of genomic DNA to find a gene?

I am reading fw2.2: A Quantitative Trait Locus Key to the Evolution of Tomato Fruit Size (doi: 10.1126/science.289.5476.85). The authors are trying to find the gene that makes tomatoes bigger. As far ...
2
votes
0answers
12 views

Cosmid genomic library, or genomic cosmid library?

Which usage is better for referring to a "cosmid library of genomic DNA fragments"?
0
votes
1answer
23 views

How does mutation work natural population? and is it common in protists or prokaryotes?

Why is it inevitable that evolution by mutations alone should be a common cause of evolutionary change in most natural populations? And do you expect mutation-driven evolution to be more common in ...
5
votes
1answer
39 views

Is a sequential double transformation acceptable?

Standard protocol states having two compatible vectors being transformed simultaneously during the same procedure. I've come across a situation in which transforming one vector, obtaining results, and ...
2
votes
0answers
16 views

What are the roles of guanidine-HCl and ethanol in binding of DNA to silica?

I'm trying to understand how exactly the binding to silica gel (in kits) step works and I cannot find any papers which provide an explanation of the physics or chemistry; especially on the way that ...
8
votes
3answers
798 views

Was the mitochondrion or chloroplast first?

I still don't know if the mitochondrion or chloroplast was first? I've looked for it on the internet and in various books but haven't found anything. Does anyone have the answer and a theory which ...
1
vote
1answer
40 views

Life on other planets [duplicate]

first of all I'm not sure if I should post this here or in the astronomy stack. I think biologist are more likely to answer my question. To make it short: Why when looking for any sort of life on ...
1
vote
1answer
58 views

What does min mean?

I read that "trp operon is located at 27 min on E.coli chromosome." What does "min" mean ?
0
votes
1answer
26 views

How do I determine the parental type here?

Please consider the following question: You cross Drosophilia and receive the following offspring: 965 wild-type, 944 black- vestigial, 206 gray- vestigial, and 185 black- normal. Explain your ...
0
votes
0answers
9 views

What causes human hair to go gray? [duplicate]

What causes the graying of human hair? Additionally, why does extreme stress bring it on faster?
1
vote
1answer
35 views

How do Gram + bacteria use a proton gradient for F-type ATPase?

Does anyone know of any papers showing how Gram positive Fermiculates or Actinobacteria use a H+ gradient for an F-type ATPase, It seems impossible since there is no outer LPS membrane to maintain ...
0
votes
1answer
22 views

Property of E.coli harboring F element

From Genetics by Ursula Goodenough E.coli harboring an F element are endowed with a number of phenotypic traits : 1.They are sensitive to infection by ssRNA phages and certain ssDNA phages. ...
2
votes
2answers
69 views

Effect on fitness of mutations

What is the distribution/probability density function (PDF) of impacts on fitness of new mutations? I very welcome any partial answer that does not give the whole PDF but just some information ...
2
votes
1answer
30 views

Dominance/recessivity of new mutations

What is the distribution/probability density function (PDF) of recessivity/dominance of new mutations? I very welcome any partial answer that does not give the whole PDF but just some information ...
2
votes
1answer
45 views

Additive genetic variance with $n$ loci

The genetic variance of a quantitative trait (the quantitative trait in question is fitness) can be express as the sum of two components, the dominance and additive variance: $$\sigma_D^2 + ...
1
vote
1answer
72 views

Additive genetic variance with $n$ alleles

The genetic variance of a quantitative trait (the quantitative trait in question is fitness) can be express as the sum of two components, the dominance and additive variance: $$\sigma_D^2 + ...
3
votes
1answer
34 views

Brainbow fluorescence labeling technique

I have this picture describing the Brainbow system here: The paper I am reading says it uses Cre-lox recombination to express a certain color. If the cell in question was expressing a yellow ...
1
vote
2answers
48 views

In what ways can mechanisms of apoptosis be damaged?

How many ways can an Apoptosis mechanism be made disfunctional or irreparably damaged? If a cell has damaged Apoptosis mechanisms and it divides will its daughter cells have such damage?
0
votes
0answers
19 views

People say the cardiac cycle depends on blood pressure? How so?

I know what the cardiac cycle is. There are two phases diastole and systole. One is the relaxed, and the other is the contracted form of the heart. The diastole is where blood is pumped to the ...
2
votes
2answers
33 views

Role of Melatonin in Circadian Rhythm

Melatonin regulates the wake-sleep cycle by causing drowsiness and lowering body temperature, but which specific chemical pathways lead to this drowsiness?
1
vote
3answers
49 views

Does DNA influence death (e.g. by cell aging)

I know that we age because of errors in the cell replication process and these errors eventually leads to death. If we exclude environmental factors, are there any other factors that can cause these ...
2
votes
2answers
47 views

Real time PCR normalization algorithm

When performing normalization of real time PCR results, I found two ways of doing it: In my lab they follow the next layout: $efficiency^{-(CT\ interest\ gene - CT\ housekeeping)}$ each time ...
1
vote
1answer
27 views

Nervous System : Organ or Gland Failure

If an organ was to start failing, not total failure, such as the thyroid gland, is it possible that the fault may not lie in the failure of the organ but in the nerve signals coming from the brain?
1
vote
1answer
23 views

Nervous System : Signal Translation

If a device were created to monitor the nervous signals from the heart, including stable heartbeats, rapid heartbeats, etc., and this device were capable of transmitting the "stable heartbeat" to the ...
1
vote
1answer
20 views

Nervous system : Nerve signals [duplicate]

If the electrical signals from all the various organs throughout the body eventually connect to the nerves in the spinal column traveling up to the brain, how does the brain differentiate the ...
1
vote
1answer
28 views

Nervous system: Pain and Pleasure?

If you have a constant pain in your body, why does a greater pain or pleasure make you not feel the original pain?
0
votes
0answers
31 views

Cloning a gene of an organism with an nonsequenced genome

What would be the best protocol to clone a gene about 5kb in size? The genome is not sequenced, but the gene itself very similar to orthologous genes of organisms with known sequences.
1
vote
1answer
43 views

Do chickens always lay eggs?

http://de.wikipedia.org/wiki/Hühnerei says it takes up to 24 h for a chicken to produce an egg. Is that dependent on the chickens nutrition, i.e., if it does not get enough food or the wrong kind, ...
1
vote
1answer
53 views

building intelligent structure with random evolution requires series of non useful steps

In order to build an intelligent design such as a bridge or a mechanical watch, you need a series of non useful steps. As far as I understand, in random evolution theory, the "intelligence" involved ...
1
vote
1answer
28 views

How do ants spontaneously grow wings?

On hot summer nights we get flocks of ants that have grown wings (from what I know to migrate nests). It appears the wings are not permanent, but are grown for a temporary purpose. From what I ...
2
votes
1answer
33 views

Substitute 25mM dNTPs mix with 10mM dNTPs

I need to make a solution of multiple compounds, one of them is dNTPs. The recipe calls for 20 μl 25 mM dNTPs in a 1250 μL master mix. Unfortunately I do not have it available at that concentration, ...
2
votes
1answer
27 views

Stomach Virus : How does it affect the bacteria of the intestines?

When you have a stomach virus and it causes extreme bowel movements to the point of almost pure stomach acid, does this kill off the bacteria in our intestinal tracks?
1
vote
0answers
29 views

Banana-only diet for humans [closed]

This YouTube channel appears to advocate a diet consisting almost entirely of bananas. From a biological point of view, does such a diet have any benefits? Or is this, as I suspect, dangerous ...
1
vote
2answers
38 views

Advantages of pain sensation?

The hazards of congenital insensitivity to pain (CIP) are well-known. This question is about the obverse: what selective advantage, if any, does the normal sensation of pain confer? I'm thinking of ...
3
votes
1answer
37 views

Significance of lipids in biological membranes…?

Membranes are specifically designed by lipids to maintain internal hydrophilic environment in narrow range.There are hydrophobic amino acids among naturally occurring 20 amino acids and as well as ...
0
votes
1answer
23 views

Can inhibition of lymphocytes migration be a direct cause of chronic inflammation?

Here is the original slide: I am thinking about the "cord factor" sentence in a more general case. Assume you inhibit Leucocytes migration. How does this lead to accumulation of macrophages in the ...
0
votes
1answer
31 views

How can a recessive allele propagate until they manifest?

Suppose a specific gene has two possible alleles. In a given population all members have only the dominant one. By a mutation on member receives the first recessive allele of that population. Is it ...
1
vote
1answer
25 views

Cells created using differently aligned proteins

I remember reading that scientist were making cells (I assume bacteria), that used differently oriented proteins to create a whole new class of life. Because apparently right and left aligned proteins ...
3
votes
1answer
20 views

Function of heparin and dextran sulfate for removing proteins

From this article : The reaction was terminated and the histones, and most nonhistones, were removed by adding the nuclease-treated chromosomes to a solution containing dextran sulfate (2 ...
3
votes
1answer
20 views

Changing time and rpm of centifuge

Inspired by this question, I want to ask a question about centrifugation. Suppose a protocol says : 10 min at 2500 rpm . Can we instead centifuge for 5 min at 5000 rpm or 20 min at 1250 rpm ?
1
vote
1answer
40 views

Missing 4$H_2O$s (per glucose) in Cellular Respiration… Where can they be?

I having trouble understanding the equation of the cellular respiration. The thing that bothers me is the number of $H_2O$ molecules. Generally, cellular respiration is written thus : $C_6H_{12}O_6 + ...
1
vote
1answer
43 views

What is the biological reason that some viruses cause sore joints (eg flu)?

Frequently I have experienced sore joints during a bad bout of influenza. I understand that during time of sickness, white blood cells are deployed in the blood stream. I also believe that white blood ...
1
vote
2answers
20 views

Concerning Apoptosis

What if cellular growth and repair is 'forced' to occur repeatedly in a region where it wouldn't normally happen , if the biological area was 'healthier'. Could this more aggressive cellular growth ...
3
votes
2answers
49 views

Is half-a-tablet of X a substitute for a tablet of X/2?

This may be anecdotal. At the pharmacy earlier, the prescription called for a drug with X mg of the target chemical. The pharmacy however only had stock of a higher potency of the same brand. E.g. ...
5
votes
0answers
28 views

E coli cotransformation efficiency

What is the E coli transformation efficiency for 2 plasmids? Are any studies that have looked at the correlation between number of plasmids transformed and transformation efficiency? Is there a ...
3
votes
1answer
37 views

Does yeast grow on LB agar plates?

I would like to grow E coli cells on cellophane on top of LB plate, and then grow yeast cells on the same LB plate. Does (or how well) yeast grow on LB plates? Is there a composition media that can be ...
1
vote
1answer
34 views

Why can't my body deal with cold-sores

I am not a biologist, but I have always wondered why my body hasn't learnt to deal with the HSV-1 virus. I understand it reamins dormant for a while and things like stress or the common cold can ...

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