1
vote
2answers
359 views

Complementarity Determining Regions (CDR)

Complementarity determining regions (CDRs) are part of the variable chains in immunoglobulins (antibodies) and T cell receptors, generated by B-cells and T-cells respectively, where these molecules ...
2
votes
1answer
30 views

How are 23 chromozomes in human sperm chosen?

I'm not biologist and I have just a basic knowledge. I've been thinking for a long time about the following question: How does the body choose which 23 chromosomes should be active in human sperm and ...
5
votes
1answer
178 views

Are bacteria necessary for an individual's life, or, how long could a person live without bacteria? [on hold]

Bacteria are essential to life in that they are responsible for breakdown of organic substances, etc. but are bacteria necessary for an individual's life? In other words, how long would a human ...
0
votes
0answers
3 views

When a muscle contracts, where does the force go?

Geometrically speaking, a muscle contraction should exert a force between the two attachment sites. However, the actual effect of the force on the overall geometry of the body near the point of ...
4
votes
2answers
16 views

Are there cats with black skin?

Some mammals can have a black, pink or spotted skin, depending on race - see for example humans or pigs. But I recently learned that this is not the case with mice. Even black furred mice have pink ...
0
votes
1answer
12 views

Biochemical coupling between two enzymatic reactions - Enzymes physically associated?

I am wondering what the exact definition of biochemical coupling between two enzymatic reactions is. I know that these two enzymatic reactions have to share the same intermediate(s) one is ...
4
votes
1answer
49 views

Why does high pH result in the denaturation of DNA?

In the Southern blot method, for example, a solution of NaOH is used to denature the DNA in the sample. I find this counterintuitive since I expected that $\text{Na}^+$ cations would neutralize the ...
0
votes
0answers
43 views

Can DNA & RNA be considered as nature's programming language?

The final frontier of Biological Sciences could be considered understanding the effects of variation in the DNA (and RNA). If after fertilization the DNA of the zygote could be genetically ...
2
votes
1answer
21 views

Survival of streptococcus after my scarlet fever

I'm currently sick because of scarlet fever but I got treated with antibiotics. I know that after 1.5 day using antibiotics the streptococci I release at home are dangerous anymore. But my question ...
0
votes
0answers
12 views

Multivariate Generalized Linear Mixed Model [on hold]

I'm trying to run a multivariate generalized linear mixed model on a data set. I have 4 response variables, 3 fixed factors, a covariate and a random factor. SPSS can't do the analysis. I've tried ...
4
votes
2answers
30 views

What (open) software there are for simulating behaviour of human (cortical) neurons?

Is there any reliable open-source software for simulating the behaviour of human cortical neurons? I am looking for serious software, so let's assume I have access to a computer with more than 10,000 ...
1
vote
0answers
21 views

What's the (or some of the) minimum(s) amount of atmospheric carbon dioxide needed by plants?

We currently have a problem of increasing CO2 in the atmosphere. But assuming we find a way to carbon sink it, what is the minimum CO2 we need to leave in the atmosphere to provide a source for ...
0
votes
0answers
11 views

How can TMS induce depolarization?

Depolarization needs at least tens of mV potential difference across the membrane to occur. But the membrane is really thin, surely less then 0.01µm (some reference give 25A). Then the potential ...
1
vote
0answers
13 views

protein with highest affinity to lactose

I was wondering: What is the protein with the highest affinity to lactose ? Are there some databases with values for affinity ? Thanks in advance
0
votes
0answers
12 views

How do I use BEAST for divergence time estimation in this case?

I am interested in using BEAST to find the divergence time estimates of species separations within a genus of frogs. The genus separated from a outgroup taxon I have chosen around 80 million years ...
1
vote
0answers
61 views

White/Gold vs Blue/Black dress [on hold]

So I'm sure you've all seen the dress photo where people see the dress as either White and Gold or Blue and Black. It has essentially 'split' the internet because some people see the dress and they ...
9
votes
2answers
109 views
+50

Why do we urinate more when we are nervous?

This question is a result of my personal experience... But I guess that is common for many of us. My school timing is 8:00 am to 1:30 pm (usually). During normal school days I typically urinate one ...
0
votes
0answers
9 views

What is the chemical makeup of mealworm frass?

We have been raising mealworms for some time and while mealworm frass has proven very useful as a plant fertilizer, I started wondering about other potential uses of this leftover waste. Can someone ...
0
votes
0answers
10 views

What are the forms of host pathogen interaction [on hold]

What are the forms of host pathogen interaction apart from the host pathogen protein protein interaction?? Or is protein protein interface is the only one way of host pathogen interaction??
0
votes
1answer
12 views

What is the role of Aspartate Transaminase in gluconeogenesis?

I know that oxaloacetate cannot cross the mitochondrial membrane, but can instead be converted to aspartate, shuttled out, and then re-converted back to oxaloacetate. What does this have to do with ...
0
votes
0answers
18 views

Common properties of herbs in creating anaphrodisiac effect?

Recently came across Wiki article about anaphrodisiac herbs and other products. An anaphrodisiac (also antaphrodisiac or antiaphrodisiac) is something that quells or blunts the libido. It is the ...
0
votes
0answers
14 views

How to get chemical structures in PDB format?

I am about to embark on the final step of a research project that involves molecular docking. Specifically, I am planning on docking an alpha(2,6)-linked sialic acid glycan to the influenza ...
2
votes
0answers
11 views

To which negatively charged components of the cell envelopes do the crystal violet complexes bind in gram staining?

The gram positive have negative components in the peptidoglycan layer in the form of teichoic acid phosphodiester bonds, and the gram negative have negative components in their outer membrane in the ...
6
votes
1answer
48 views

Which will produce more oxygen? Less number of (larger) trees or more number of (smaller) plants?

In a given area A, we have two choices - (i) we can plant maximum number of trees (which are larger in size) possible in A, say m OR (ii) we can plant maximum number of plants (which are smaller in ...
2
votes
1answer
23 views

Detailed mechanism of the cause of diabetes mellitus type 1?

I have read in some texts that diabetes mellitus type 1 is caused by degeneration of beta cells due to our body's own immune reaction.Is it true? Can you explain further how are such types of immune ...
3
votes
0answers
9 views

Procedure for doing western blot [on hold]

I am writing a step by step guide for doing a western blot for a class. It is intended for any one with basic Biology lab skills. I am hoping people will review my draft and give feedback on how to ...
1
vote
1answer
30 views

What are pseudoknots?

I'm trying to get my head around what a pseudoknot is and how I can identify them given some RNA string. For example, suppose I have a string s = CGUUGUGUACACGAUAGUACAU. Suppose the two longest ...
3
votes
1answer
79 views

Why is the upper respiratory tract so vulnerable to infections?

Wikipedia has the following statement on its Upper respiratory tract infection page: In United States URIs are the most common infectious illness in the general population. What is it about ...
3
votes
1answer
32 views

Strange Cordeyceps-looking Mushroom in Australia

In the past few weeks, after the rain started up I noticed these mushrooms around my local area. I'd never seen them previously out of the 20 years I've lived here (a town in Queensland, Australia). ...
0
votes
1answer
20 views

What is the role pyruvate carboxylase in lipogenesis?

I just know that Acetyl-CoA is a positive allosteric modulator for pyruvate carboxylase, but I cannot find anything else.
2
votes
1answer
40 views

The human organism knows what we have to eat? [on hold]

My mother has told that if your organism needs a vitamin, you want fruits include that vitamin. For example you have lack of C-vitamin you would like to eat lemon. Is there any explanation for it, or ...
11
votes
2answers
68 views

Are codons that map to the same amino acids interchangeable?

(disclaimer - I'm just getting interested in genetics so sorry if this is an obvious/silly question.) From wikipedia, in the section on the RNA codon table, I see a mapping between codons and amino ...
2
votes
0answers
37 views

Are there anyother method under research for curing rabies? [duplicate]

Why is rabies incurable after onset of symptoms? Although we administer HRIG (lyssa virus antibody) to the patient, why doesn't it work after onset of symptoms? And are there any other successful ...
-1
votes
0answers
15 views

Case study about diabetic woman with comminuted fracture [on hold]

A middle aged diabetic woman is taken to ED after a MVA (motor vehicle accident). She has a compound fracture of her tibia. Imaging shows a comminuted fracture. In respect to this patient describe the ...
0
votes
0answers
19 views

How do genetic chimeras with different blood types not die?

If a person is a chimera and has two different blood types in his veins, how does he not die? Shouldn't the immune system attack one of the blood types? In 1953 a human chimera was reported in the ...
0
votes
2answers
43 views

What is the effect of persistent hypothermia on cardiac performance?

I define persistent hypothermia in this thread about the mechanisms of persistent hypothermia. The Graph of Katzung et al. in Pharmacology about Heart Failure: I am thinking which parts here are ...
0
votes
1answer
142 views

Alternative protocol for evaluating RNA integrity, using a bleach gel

I hate having to run MOPS PFA agarose gels with DEPC and everything just to verify my RNA integrity. I came across an alternative protocol that uses ordinary household bleach in the gel to inhibit ...
1
vote
0answers
29 views

why plants cannot use atmospheric nitrogen? [duplicate]

Earth's atmosphere constitutes 78% of Nitrogen, then why do plants need to absorb Nitrogen from the soil. Why couldn't it possible for them to absorb the atmospheric Nitrogen like they do in the case ...
3
votes
0answers
26 views

How can I reduce the background gradient in phase contrast microscopy?

I'm looking for ways to set up a phase contrast microscope to reduce the brightness gradient that appears across the background of my images. I use phase contrast to find the outlines of cells in my ...
0
votes
0answers
39 views

“Gold standard” for CNV detection methods?

Is there a generally accepted "gold standard" for testing the performance of CNV detection methods? I'm interested both in learning about existing datasets that may serve as gold standards for CNV ...
0
votes
1answer
33 views

Why are twins so similar? [on hold]

It strikes me that it could be the same conditions of the fetuses in uterus or the same conditions of the sperms, but I am really not sure in this way. Thanks.
2
votes
2answers
56 views

Why is it that heterozygous loci appear as two separate bands during gel electrophoresis while homozygous loci appear as one band?

Is it because heterozygotes have a greater base pair length? (And if they do, why is that?) Or is it because recessive alleles are moving slower than the dominant alleles in the gel?
1
vote
2answers
41 views

How does the size of insert affects the rate of Homologous Recombination in yeast?

When performing genetic knockouts in yeast using homologous recombination to replace a target gene sequence via a vector DNA, does the region between the flanking regions in the vector have to be the ...
1
vote
1answer
39 views

What is the difference between gene and CDS annotations?

I have a bunch of sequence files fetched from the EBI ENA and I'm trying to find the end of the 5' UTR for specific genes. The UTR itself doesn't seem to be annotated in most sequence files I have. ...
1
vote
1answer
30 views

How does ANF increase GFR?

ANF as we know reduce the Na+ uptake and K+ removal in the distal tubules and it also functions as a Vasodialator (?) But again it says that ANF increases the Glomerular filtrate ? But if it is acting ...
0
votes
4answers
32 views

How does HIV mutate into other strains while keeping their virulent phenotype?

How does a virus like HIV mutate into so many strains, and yet all of them are harmful to our immune system? What gives this virus the ability to mutate so efficiently?
6
votes
1answer
54 views

How much total RNA can be extracted from Drosophila brain

I am wondering how much total RNA could be extracted from a single D. melanogaster brain. I could not find this information from the literature. The closest hit was this paper, that claims that ...
0
votes
0answers
10 views

Does all fungi has has N-Acetyl Glucosamine (Chitin) as the main component of their cell wall?

I came across a question which somewhat goes like In which of the following kingdom, MOST of the members have a cell wall made of polysaccharide and amino acids ? - Monera or Fungi. To me it looks ...
4
votes
1answer
18k views

Why are (some) cats attracted by bleach?

(Sorry if this question is only partly biological) I have noticed that several cats (including the one that keeps sleeping in my house), are fond of the odor of bleach (eau de Javel) and chlorine. ...
12
votes
1answer
4k views

Fish “coming back to life” after being frozen

I've encountered a clip on Youtube showing a goldfish thrown in liquid nitrogen and immediately after to normal water and swimming normally. In the explanation to the clip it says: For everyone ...

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