7
votes
1answer
215 views

Refractory period in action potential

I know that the part E in this graph is definitely the part of refractory period. My question : Will there be any effect on B,C or D if a stimulus is given at time B,CorD respectively ?
1
vote
1answer
71 views

Molting in arthropods

Do all the arthropods molt ? Which ones do not molt ? Why don't they need to molt ? I tried googling this - but did not get satisfactory answers.
2
votes
1answer
81 views

Hibernation in ectotherm and endotherm

Both snake and weasel hibernate. Which of the following is correct? A. They will die when temperature decreases below the critical temperature. B. Weasel will die when temperature ...
0
votes
1answer
56 views

probability of having normal daughter

If father has hemophilia, mother is a carrier of the disease, then what is the probability of having a normal daughter ? My question: Should the probability of having a daughter be also ...
5
votes
1answer
160 views

Are HeLa cells edible?

I'm curious if HeLa cells are intrinsically poisonous or dangerous to ingest. My understanding is that some of the contamination in HeLa cells such as HPVs are not readily expressed. I have no plans ...
1
vote
0answers
22 views

Are sulfates or nitrates common ions in biochemistry (specifically of the body)?

It's a rather broad question but something I'm curious about. I know sulfates tend to be very soluble ions and so don't know nitrates. I also know that phosphates are extremely common in ...
1
vote
1answer
41 views

Vesicular and non vesicular transport

I have to classify them either as transported in vesicles or without vesicles. What I think - Non-vesicular 2.vesicular 3.vesicular 4.vesicular 5.non-vesicular 6.vesicular 7.vesicular ...
-1
votes
2answers
567 views

How did fish evolve the ability to breathe on land?

Doesn't make sense. It would be like a human evolving the ability to breathe on the moon without a spacesuit. How would the organism be able to carry out such an evolutionary adaptation, when the ...
0
votes
2answers
110 views

What is “transcribed strand”

This is an excerpt from a paper: T>C mutations at NpTpN trinucleotides, also found in hepatocellular carcinomas, shows strong transcriptional strand bias with more T>C mutations on the transcribed ...
4
votes
2answers
110 views

Reference sequence for defining single nucleotide polymorphisms

Single nucleotide polymorphism (SNP) or genetic variation in general, by definition are relative to a reference sequence. When we talk about databases of SNP as in ("dbSNP—Database for Single ...
4
votes
1answer
37 views

What determines the thickness of Cornea?

In eye-operations such as Lasik and Femto, the thickness of cornea is key decision factor whether the operation is feasible. A normal thickness is between 500-600 µm. Cornea consists of a very special ...
2
votes
1answer
1k views

what is the difference between early blight of potato and late blight of potato?

apart from different fungus causing these diseases in potato, how are Early Blight of potato and Late blight of potato different?
2
votes
1answer
128 views

DNA ligase mechanism

I am unable to understand what happens to the phosphates from ATP. What are they used for ?Charging 3' end or 5'end ?
1
vote
4answers
185 views

Significance of having goosebumps?

What help does goosebumps do to us? I don't think it helps us noticeably when we are scared or shivering.
0
votes
1answer
2k views

What happens to our body when we undergo a sudden temperature change?

We know that a glass gets cracked when it undergoes sudden change in temperature. But what will happen in the case of a human body if it changes from the maximum(>35 C) to the minimum ...
0
votes
1answer
340 views

SNP genotyping using PCR

I read this wikipedia article on SNP genotyping and wasn't able to understand this part : In examining the results, if a genomic sample is homozygous, then the PCR products that result will be ...
1
vote
1answer
113 views

Recalling memories by electrical impulses?

I've read that in an experiment, a pair of stimulating electrodes were inserted into a blind man's visual cortex, and upon passing electricity, the phosphene phenomenon was produced. Is it the same ...
1
vote
2answers
635 views

Gel electrophoresis after RNAse treatment

I do not understand how to solve this question. I know that RNAse will cut smaller pieces of RNA. The answer given is A
2
votes
1answer
46 views

Allergic rhinitis vaccine

Note : Any answer to this question will not be (and should not be) taken as medical advice. One of my friends has allergic rhinitis and has been prescribed an oral vaccine. He is allergic to 3 ...
2
votes
2answers
203 views

Are there enzymes found in nature or the man made world that can help break down metals?

The title says it all. Do natural or human engineered enzymes exist that can speed up the break down kitchen utensils, aluminum cans, wires, etc. into small particles or powders? To be clear I am ...
0
votes
1answer
26 views

Different level of toxicity between smoke

Has there been studies on the difference between the smoke generated from: cigarette or cigar manufactured by brands which are proven to contain more than a hundred of dangerous additional ...
2
votes
1answer
71 views

Physiological reason why leaves got twisted when treated with indole acetic acid

I want to know the physiological reasons of why the leaves of my study plant got twisted when treated for 10 days with spray of indole acetic acid. I want to treat seeds with IAA, and I'm thinking ...
2
votes
1answer
69 views

Where to obtain metabolic pathway datasets

I've been looking through the files available at www.reactome.org along with some others but I only find images/pdfs of metabolic pathway diagrams. Where is the actual data these pathways are drawn ...
3
votes
1answer
143 views

Real-time PCR delay in Cq due to insertion SNP in primer

I am collecting evidence, even anecdotal, how does single nucleotide deletion or insertion in primer region affect the outcome of real-time PCR. I am most interested in how much there is a delay in ...
1
vote
0answers
27 views

Systematic anticoagulant injection after a CVA

Since most of the cerebrovascular accident are ischemic ones, would it be usefull to have anticoagulant everywhere (we already have AEDs everywhere) so that everytime someone would have symptoms of a ...
2
votes
1answer
76 views

Can cerebrospinal fluid deliver nutrients/drugs to neurons during sleep?

I'm looking at this article on the possible mechanism of detoxifying brain during sleep using cerebrospinal fluid. It states that at night, the space between neurons may allow better (up to 20x) ...
4
votes
1answer
88 views

H₂S as a source of electrons for plants

The first electron source for plants was H2S, but now most modern plants use H2O as an electron source. What is the advantage of using H2O instead of H2S?
2
votes
1answer
332 views

How can Southern blotting be used to establish gene copy number?

I am reading a paper on a certain marine microorganism that can eat alkanes and therefore might be useful for cleaning up oil spills, etc. This sentence struck me as odd (although I am sure that the ...
2
votes
0answers
53 views

Could below zero decibel environment cause arrhythmia? [closed]

While this topic has virtually no real life application and has never been examined due to obvious reasons, it is quite intriguing to me. I've read a lot of speculations and claims about the world's ...
4
votes
2answers
409 views

Why is the strength of genetic drift inversely proportional to the population size?

I saw a concept on the Internet that says "the strength of genetic drift is inversely proportional to the population size". I don't know why they are inversely proportional? Can somebody explain? ...
2
votes
2answers
120 views

Stay young by reinserting own DNA from years ago?

As far as I know, the DNA sequence becomes shorter every time a cell divides. A shorter sequence results in information loss and aging characteristics. As a countermeasure, shouldn't one stay young ...
1
vote
1answer
75 views

How suddenly does lactose-intolerance onset?

How quickly can the loss of lactose tolerance onset in an adult? Such as being able to process lactose normally to having notice symptoms associated with the inability to process lactose. I am not ...
3
votes
1answer
89 views

Chromosome 2 alternate explanation - apes gaining a set of chromosomes?

I'm preparing for a debate (just between friends) on evolution (I'm in support), and one of the points I plan to bring up is the Chromosome 2 evidence. I'm now trying to predict their potential ...
1
vote
1answer
55 views

Can germs develop surfactant resistance in a harmful way?

Germs can develop antimicrobial resistance. It is a problem serious enough to deserve an FAQ page on the WHO website (http://www.who.int/mediacentre/factsheets/fs194/en/). But how about surfactant ...
0
votes
1answer
35 views

Is it possible for bacteria to acquire family-wide antibiotic resistance?

If there is bacteria, lets say Enterococci that is sensitive to: Amoxycillin-Clavulinic acid Ampicillin-Sulbactam Ofloxacin Ciprofloxacin Is it possible to ...
1
vote
1answer
101 views

Prothrombin time when extrinsic pathway is turned off

I was searching for an answer that "why do we need intrinsic pathway when there is fast extrinsic pathway" and i found the answer in the following link: http://www.pathologystudent.com/?p=3197 It ...
5
votes
2answers
131 views

Can you tell the sex of a white willow when it's not flowering?

Can you tell whether a salix alba tree will produce male flowers or female flowers by looking at it, touching it or generally using your unaided senses? If not, is there any way to do that without ...
3
votes
0answers
84 views

Could miniaturization be used to protect endangered large species?

In some animals (like dogs) size seems like it's controlled mostly by just a few genes (IGF1, and the genes that repress it). I'm curious: (1) Does other miniaturization takes a similar route (for ...
4
votes
2answers
147 views

Asexual reproduction and Telomeres

Many eukaryotic organisms like yeasts, hydras , planarias, plants etc reproduce asexually. Replication of End of linear DNA pose a limit to the number of cell divisions. My question : Do asexually ...
0
votes
1answer
290 views

A basic example of the interactions of 2 or more non-identical alleles leading to an advantageous outcome for an individual organism

Could someone help me out with a basic example of the interactions of 2 or more non-identical alleles leading to an advantageous outcome for an individual organism? Based on empirical research OR on a ...
3
votes
1answer
48 views

Process of Transcription

During the process of Conversion to Ribonucleoside Monophosphates the various ribonucleoside triphosphates break off their high energy bonds after linkage to the DNA.But the first ribonucleotide ...
0
votes
0answers
20 views

Why do our limbs and other body parts get numb/feelingless and then they start to tickle? [duplicate]

Why do our limbs (legs, arms) get numb/feelingless when they are under prolonged pressure or when one has crossed his/her leg while sitting for a long period? After we move it to a more relaxed or ...
4
votes
1answer
168 views

Beetroot white skin mould

Does a mould make a beetroot poisonous or inedible ? Lemon's mould for instance, makes penicillin, but it's green there, and I'm allergic to penicillin, would the white mould produce penicillin too? ...
2
votes
1answer
41 views

What is mRNA expression level?

I cannot find clear explanation of what is mRNA expression level, and how to measure it. I would appreciate if someone explained it or gave a reference. Thanks!
1
vote
1answer
1k views

Evolution- Variations, adaptations and selective advantages

I am trying to understand Variations, adaptations and selective advantages and how they are all related. Feel free to add or correct me if I'm wrong- Variations are structural, functional, or ...
2
votes
0answers
55 views

Circadian rhythm in birds

Animals can use their circadian clocks to determine direction from the position of the sun. In a particular experiment conducted in Iceland, a bird, kept in a cage open to the sky, was trained ...
1
vote
1answer
4k views

What's the difference between protein and DNA behaviour during agarose gel electrophoresis?

I'm planning a science project about gel electrophoresis, and I'd like to know if there are any measurable, quantifiable (for example, things I could represent in a graph or chart) differences between ...
2
votes
1answer
297 views

Opposite results between Blomberg's K and phylogenetic signal in Phylocom (AOT)

I've been trying to test for significant phylogenetic conservatism in some plant traits. So far I used R-package picante (Blomberg's K) and AOT in Phylocom. So far these two methods yield completely ...
5
votes
1answer
366 views

Why does wood become darker when it ages?

I have lots of pieces of pine furniture which have different colours depending on how old they are. So, I just wondered why that is. I guess it has something to do with structures and chemical ...
1
vote
1answer
119 views

Can we say that microevolution and macroevolution is fundamentally the same thing over different time scales?

This Wikipedia article states: Macroevolution is evolution on a scale of separated gene pools. Macroevolutionary studies focus on change that occurs at or above the level of species, in contrast ...

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