3
votes
1answer
41 views

Mathematical models of lineage selection

I'm interested in the concept of lineage selection (Aboitiz, 1991) as an explanation for why traits would be selected for that enhance the rate at which evolution can occur, rather than directly ...
0
votes
0answers
14 views

Steps in making mass/volume concentrations? [duplicate]

[TLDR When making mass/volume concentrations, is the general workflow to make a stock and dilute from it to yield the proper diluted concentrations? Could anyone detail their methodology on the ...
2
votes
1answer
17 views

Is it possible to accurately measure micronutrient levels with the blood volume from a Dermal / Capillary puncture?

I have not been able to find much information beyond what tests are normally done with Capillary puncture sampling, as opposed to what tests are possible. Could we test for a single micronutrient, or ...
3
votes
1answer
39 views

What color was the most recent common ancestor of all swans?

Was the most recent common ancestor of all swans black, or white, or some other color? How do we know, and how certain can we be?
2
votes
2answers
168 views

Using an analytical balance (0.0000 precision) to measure µg (micrograms)?

If i needed to prepare 200µg/ml of proteinase K, and the proteinase K was in a solid powder form, would I have to weight out 200 µg using an analytical balance, and if so, is it possible with a ...
1
vote
0answers
16 views

Is this a legitimate teratoma for a human pluripotent stem cell assay?

I can't quite make out this teratoma: ...
3
votes
2answers
44 views

Sequence compression method / format

As someone working with sequencing data and sequence files I was wondering whether is there a compression method / format for sequence / read files? Of course one can use general compressors like rar ...
-1
votes
1answer
46 views

How to make µg/ml concentrations of proteinase-K?

How does one prepare concentrations in the mass/volume (weight/volume) form, for substances like nucleic acids or in this case, proteinase? A detailed example would be helpful. I need to prepare ...
5
votes
2answers
46 views

What percentage of a cell's volume is occupied by protein?

I was looking at one of David Goodsell's illustrations of a cell: And it seems to suggest a very crowded picture of the intracellular environment. Just how crowded are cytoplasms? What percentage ...
1
vote
0answers
35 views

Primer Designing [on hold]

I have a basic idea about the requirements in primer designing. Basically my knowledge is limited to theoretical knowledge and have no experience in actual primer designing. And also I have a basic ...
2
votes
1answer
30 views

Is the Klein's bottle a good analogy to the relation between T-tubule and sarcolemma? [on hold]

I am not quite seeing how the T-tubule and sarcolemma is connected. It says that the T-tubule is an "invagination" of the sarcolemma, which is sarcolemma folded from the inside to form a T-tubule Can ...
2
votes
1answer
58 views

Can silverfish climb and produce silk?

I am equally disgusted and fascinated by the "Silverfish" (Lepisma saccharina) that we regularly find in our UK home. I tried searching for information on the internet but they seem poorly understood. ...
2
votes
0answers
38 views

Examples of Vestigial Genes

I consider the existence of a broken GULO gene in humans to be the clearest evidence for human evolution - just what else is it doing there otherwise? Are there any other examples of vestigial genes ...
2
votes
0answers
25 views

Contact Inhibition of Cell Division: Signaling Pathway

The following article refers to contact inhibition of cell division in epithelial cells, specifically MDCK cells: Collective and single cell behavior in epithelial contact inhibition. In their review ...
0
votes
0answers
31 views

What are possible physiological causes for dry, irritated facial skin when failing to shave? [on hold]

I am aware that skin can become dry and irritated AFTER shaving, but what could be a reason for the same result when letting facial hair grow out? It makes sense why shaving would cause the skin to ...
1
vote
1answer
48 views

How detachment/separation works in biology?

It might be a strange question, but I'm interested in the mechanics of separation/detachment during asexual reproduction, for example when an organism reproduces by budding (I don't mean cellular ...
0
votes
0answers
38 views

How much of the biological research can be still run without high-cost high-precision instruments? [on hold]

To me it seems like much of the biological research today requires an array of expensive devices before it can be run. How much of the current research could be still done with a basic compound/stereo ...
2
votes
3answers
59 views

how to increase shelf life of yogurt without refrigeration..?

when we make yogurt at home and do not refrigerate it, it will become sour because of conversion of lactose into lactic acid by Lactobacillus bacteria, but this does not happen in case of Nestle's ...
3
votes
0answers
41 views

How does an organism know when to stop growing, whether it is already on the outermost layer? [on hold]

When a multicellular organism is under its development how does the current outermost layer of cells "know" that they should not divide furthermore, as their bodyplan coded into DNA is already ...
4
votes
1answer
56 views

How pain can stimulate the vagus nerve

I'm trying to find out why a prompt, severe, short pain is causing a stimulation of the vagus nerve. What could the physiological explanation be? Is that because the pain is triggering the ...
2
votes
0answers
33 views

How to get only perfect matches with blastn?

I have installed Blast locally and I've configured the nucleotide database to use. I want to search some sequences (from a .fastafile) in this genome. So I used blastn: ...
13
votes
2answers
2k views

Is it known how the first viruses formed?

The oldest known virus is known to have infected prehistoric insects 300 million years ago. A virus is basically a parasitic strand if DNA or RNA encapsulated in a protein coat. It enters cells by ...
5
votes
1answer
48 views

Genes-of-interest analysis between organisms

I am interested in identifying the differential expression between several genes-of-interest of different organisms. I am trying to assess the benefits of RNA sequencing over microarrays. Both ...
7
votes
4answers
848 views

Is there any way a human could whistle and be unable to speak?

Is there any situation anatomically, where a human could understand the speech of others perfectly, without any capabilities of speech themselves, but would retain the ability to whistle with a tune? ...
0
votes
2answers
21 views

Risk of autosomal dominant disorder [on hold]

What can you conclude about the risk (with each pregnancy) that a couple could have a child affected with an autosomal dominant disorder if... One parent is affected (heterozygous) and the other ...
0
votes
0answers
39 views

Punnett Square X-linked [on hold]

Color blindness is an X-linked recessive disorder. Maria has the genotype X^B X^b What is her phenotype? I put NOT COLOR BLIND Maria's husband Carlos has the genotype X^B Y I put that his ...
-2
votes
1answer
31 views

Blood Type/Punnett Square [on hold]

Male: Blood type O (Genotype written as: i^o i^o since O allele is recessive to the A and B alleles). Female: Blood type AB Draw a punnett square to show all of the possible offspring. I got Ai^o, ...
2
votes
1answer
19 views

Why are skin tactile receptors considered to be phasic receptors?

A phasic receptor by definition is one that quickly adapts to change. In terms of neuron firing, this means that it does not trigger another firing because the receptors are used to the stimulus. But ...
-2
votes
0answers
20 views

Punnet Square help [on hold]

Just wanting to make sure I am doing this correctly. Given: R dominant allele for able to roll tongue r not able to roll tongue T dominant allele for taster of PTC t not able to ...
3
votes
1answer
29 views

How to determine genotype?

In humans, the ability or inability to roll the tongue is a single gene trait. The allele for tongue rolling (R) is dominant to the allele for not being able to roll the tongue (r). Whether ...
1
vote
1answer
34 views

Serious question about a piece of meat

Does anyone know some scientific rigorous way to look at a slice of meat. I am not asking what kind of meat it is or which part of the animal it came from. I wonder what is the different lining on ...
7
votes
1answer
782 views

Where is the aneurysm in this picture?

I'm a curious person, I've never had any medical training, but I wish to know some more about aneurysms. Aneurysms are basically weakened spots in the elastic artery wall. This can eventually result ...
1
vote
1answer
28 views

What factors, other than its homochirality, make our “brand” of biology unique? [closed]

If humans were to discover organisms on another planet, it is supposed that (unless both we and they were seeded by the same source) we would have nothing to fear from alien pathogens, as they would ...
1
vote
0answers
21 views

How to gauge the clinical significance of specific cell type presence?

How does one decide whether the presence of certain cell types is clinically important or negligible? Would the presence of certain cells in conjunction with other symptoms be enough, or should it be ...
-1
votes
0answers
31 views

What is the difference between caspase and DNase? [closed]

Could somebody tell me what the difference between caspase and DNase is?
2
votes
0answers
50 views

Is the “concept of time” coded into the genome? [closed]

What I'm interested about is whether environmental changes' effects are coded into the genome, like metamorphosis, deciduous plants. Can it be explained by morphogens, or it's something completely ...
3
votes
1answer
26 views

Is there a genomic code for nucleosome positioning?

What does a genomic code for nucleosome positioning in eukaryotes actually mean? By the code is it right to think that specific DNA sequences favour nucleosomes and others don't? I see that there for ...
7
votes
2answers
38 views

Naming convention of miRNAs

I'm trying to understand naming convention of miRNAs. I've found the wikipedia article about it nomenclature Based on it, I try to figure out what is hsa-let-7a. As far as I understood, hsa refers to ...
2
votes
1answer
141 views

When contracting a muscle will the muscle spindle stretch or contract?

When you contract your muscle, will your muscle spindle stretch or contract? And why? I was always under the impression that it was contracting your muscle spindle, but now I am not sure.
5
votes
2answers
73 views

Do changes in an organism's cell modify the genetic information it uses for reproduction?

What I'm actually interested about is whether a modification in one cell during the life of an asexually reproducing organism affects its genetic information? Which cell's genetic information is used ...
3
votes
0answers
20 views

Can't resolve protein with native PAGE

This is a native gel. Let's call the left 2 lanes protein A and the right 2 lanes protein B. B is the same as A except it has a FLAG tag. They are both homotetramers of about 65 kDa. After ...
0
votes
0answers
14 views

How are Stem Cells Produced for Stem Cell Based Therapies?

I was doing an initial search on google but couldn't come up with anything I'm looking for. I know were stem cells come from and a bit about their levels of differentiation. For example, embryonic ...
3
votes
1answer
20 views

Oligonucleotide purification with desalting

I have ordered 36bp oligonucleotides that anneal to each other and create sticky ends to be cloned in a vector afterwards. I have tried cloning many times with different methods and I failed. Now I ...
-1
votes
0answers
37 views

Is technological intelligence a trait not important for survival given that it evolved only once (humans)? [closed]

And by technological intelligence I mean the ability to write down information and pass it along to children that would be able to use it in whichever way. This is probably what distinguishes us from ...
1
vote
1answer
56 views

Amino acid compatibility

The (human) genetic code encodes 20 amino acids. They form a protein using peptide bonds. Each amino acid has a carboxyl group (COOH) and an amino group (NH2) that can potentially form a peptide bond. ...
8
votes
3answers
556 views

Why are fruits so large compared to their seeds?

Why do many plants produce such large fruits(apples and strawberries,for example) if those contain only relatively small seeds?
2
votes
0answers
23 views

Finding confidence level of miRNA disease associations

I'm an undergraduate computer engineering student, and I have a project about bioinformatics. In this manner, I need to find prediction( or association I'm not sure the correct terminology) confidence ...
1
vote
0answers
24 views

Should gene therapy safety protocol include isolation?

In the case of a gene therapy trial where viral vectors are used to deliver genes into mammalian cells, including humans, should biosafety and ethical protocols include isolation of the patient as a ...
2
votes
0answers
29 views

DNA-DNA cross-linking with formaldehyde?

The 3C (chromosome conformation capture) technology for studying chromatin 3D organization starts by a cross-linking step using formaldehyde to find segments of DNA interacting. In my understanding ...
1
vote
0answers
24 views

Why can't some organisms match miRNA perfectly to the target mRNA like in plants? [closed]

What causes other organisms to be impaired in making perfect matches like plants do and is there a way to increase matching?

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