All Questions

7
votes
1answer
1k views

Single hormone opposite effects

Often, a smooth response to a hormone means that some processes must be sped up and others must be slowed down. How can a single hormone have opposite effects like this?
7
votes
1answer
273 views

What causes light to be brighter in the corner of the eyes?

I have noticed when in a dark room light and color seem to be brighter and more intense in the corner of my eyes. For example the light that comes from my digital clock seems like a dark pink when I ...
18
votes
2answers
2k views

Which organism has the smallest genome length?

Which animal/plant/anything has smallest length genome?
9
votes
1answer
167 views

Chicken Genome what are the LGE 'chromosomes'?

The chicken genome identifies two "LGE" sequences in the chicken genome. Are these distinct chromosomes or some highly variable sequence from the genome that is put in a separate sequence? I'm ...
7
votes
3answers
3k views

If I put a cup over a spider, and leave it there for a day, will the spider survive?

Will it travel more slowly since it hasn't had food for a day? What if I left the cup there for longer?
4
votes
0answers
38 views

RHEB senses amino acids in order to recruit mTOR. Do we know if RHEB is more sensitive to some amino acids (like methionine) than other amino acids?

See http://www.ncbi.nlm.nih.gov/pubmed/21157483 for the full paper describing the process of how RHEB recruits mTOR. We also discussed this in Matt Kaeberlein's class yesterday and I posed this ...
9
votes
2answers
138 views

Acknowledging differentiation of species, in historical times

This is at least partly an historical question, and I am not even remotely a biologist of any sort, so apologies beforehand if it's a little obscure. I often wonder how many distinctions were made in ...
6
votes
1answer
556 views

What forms the human amniotic sac?

I am trying to understand the formation of embryonic disc for human and chick so the following question is related to here about formation of embryonic disc. I had thought that the amniotic sac forms ...
9
votes
1answer
2k views

How many mice are on the Earth?

We are 7 billion human beings on the Earth. But how many mice are there? How would you estimate such a number?
4
votes
0answers
42 views

Serological assays not detecting native proteins

Is there anyone out there who has done much work with serological assays? We have antiserum for a manufactured viral protein but no luck so far getting it to detect native protein (unless today's ...
9
votes
1answer
187 views

What are the effects of caffeine on the mammalian circulatory system?

A friend of mine told me an anecdote about his mother, who drank too much caffeine, to the point she became hypotensive and would pass out. Because caffeine acts as a stimulant, I'm assuming the ...
12
votes
3answers
229 views

When are population dynamics models useful?

When are population dynamics models useful? There seems to have been a lot of research about it, but how does it help? If I need data about how a population will evolve under what conditions, I need ...
8
votes
2answers
149 views

What type of CCD system is required to take photos of luciferase

I'm working with luciferase and I want to be able to take a photo of it. The trouble is, I can see the luciferase glowing in all of its glory in front of me but no matter how hard I try, I can't take ...
6
votes
3answers
277 views

Where can I find the common names for the zoology taxonomy?

Forgive me if my question does not belong here or if I'm using incorrect terms, but I'm not educated in biology at all. I'm investigating the workings of the biological classification system. I was ...
9
votes
3answers
1k views

Why some genes are dominant to each other? What is the mechanism behind it?

If i have a brown eye gene which encodes the protein that is responsible for the brown color, and have a blue eye gene either, what is the reason that my eye color is brown? How does one gene ...
8
votes
1answer
480 views

How are antibiotic resistant bacterial infections treated?

For example, how are infections of antibiotic resistant strains of MRSA, Streptococcus, or Gonorrhea treated?
8
votes
1answer
232 views

How fast is the blood flow in various vessels?

How fast is the blood flow in different blood vessels, such as the aorta and capillaries?
10
votes
2answers
409 views

Why does cyanide inhibit CuZnSOD, but not MnSOD or FeSOD?

Different types of superoxide dismutase (SOD) contain different metal ions (Zn, Cu, Mn, Ni, or Fe), all of which allow them to catalyze one reaction, dismutation of superoxide anion, O2−. Cyanide can ...
9
votes
1answer
103 views

Is bootstrapping an acceptable way to determine standard error for binding constants?

I'm measuring binding constants my system and I appreciate the usual methods of using replicates to measure standard errors and using those errors to calculate propagation of error. I'm curious if ...
6
votes
2answers
201 views

PCR amplification and error propagation

Say I have one dsDNA that undergoes normal PCR (where amplification is exponential). If there is a mistake, say a G is swapped for an A during the 2nd round of replication, what percentage of the ...
4
votes
1answer
292 views

Human sleep cycles and dream times, what influences the timing and intensity? Sleep history included

I'm doing sleep and dreams research and have developed an iPhone application to help me track my bedtime, rise time, sleep onset and also mark dreams. The app also monitors overall activity overnight ...
7
votes
2answers
65 views

Is there a binding affinity metric for interactions not in equilibria?

I am investigating the strength of binding of a small peptide to a protein by isolating the bound version and subjecting it to collisions with gas molecules (CID mass spectrometry) to dissociate the ...
8
votes
1answer
400 views

Which human body hormonal systems exhibit 24 hour diurnal cyclical activity?

I'm researching the possible connection between the dream content and the activity of various organ or hormonal systems within the human body. I'm looking for information on biological cycles within ...
6
votes
1answer
264 views

How do ribosomes contribute to their own synthesis?

In other words, what products synthesized by ribosomes are actual parts of ribosomes (if any)? How are they involved in their own synthesis otherwise? What is the cycle/chain of products starting ...
3
votes
1answer
274 views

Does chicken embryo form the disc called “discoblast” in the cleavage and blastulation of chicken?

This thread is related to my previous thread which is still unsolved mainly. I need to be able to compare chick and human cleavage and blastulation of zygote. My friend says that Chicken have ...
9
votes
3answers
156 views

How is the sequenced genome of a person useful to him in practice, now?

Currently it is possible and not so expensive for a person to have his genome. This is useful in general for understanding how life works. But, in practice, how is this useful for the specific person ...
4
votes
1answer
208 views

What is the molecular mechanism of cystine bond formation?

My bioinorganic and redox chemistry isn't up to par and I'm having a very difficult time understanding the chemical mechanism behind cystine bond formation. Most reactive environments are actually ...
6
votes
1answer
162 views

Which cryogenic vials and caps are ideal for storing glycerol stocks?

There are internally threaded, externally threaded, natural caps. For the vials, there are skirts, star-footed, and various bottoms. Why do any of these things matter?
8
votes
1answer
161 views

Taxonomy for plasmids

I liked the question about F' and R plasmids. What is a good resource that describes what is known about the functions and diversity of plasmids in the wild? Prokaryotes or eukaryotes? Wikipedia ...
9
votes
1answer
2k views

Why can hair grow without limit while eyebrow cannot?

I cut my eyebrow and it grows until reach a certain length. Hair can grow without limit. Why can hair grow without limit while eyebrow cannot?
8
votes
0answers
92 views

Pancretic Acinar Cell - ATP, calcium concentration data

I need to find a decent source of data for concentration of ATP and calcium in the pancreatic acinar cell. So far all I can find is ATP or calcium 'levels' based on fluorescence , which are not ...
5
votes
2answers
139 views

How to typeset gene regulatory networks

I have a relatively simply gene regulatory network I would like to visualize, complete with the common arrow and bar symbols used to show, respectively, which genes enhance or repress with other ...
10
votes
2answers
155 views

What is the least costly method to generate sequential amino acid deletions?

I'm looking to generation sequential deletions from a gene of interest. The total size of this region is 8 amino acids. I'm trying to determine which portion of this region is necessary within the ...
16
votes
1answer
375 views

What is the lowest pressure at which plants can survive?

What is the lowest pressure at which plants can survive? How the plants behave in a Martian-type atmosphere? Is there any plant that can survive such atmosphere? Can a lichen grow at Martian ...
13
votes
3answers
734 views

Why do restriction enzymes tend to have an even number of bases in their recognition site?

When reading my textbook I noticed that in all examples but one from eight the recognition site was an even number of bases. I wondered if this was just a co-incidence, so I took the data from this ...
15
votes
2answers
2k views

Harmless virus?

Is it possible for a virus to live symbiotically with its host? Is the human body plagued with viral infections that do negligible harm, or even serve a beneficial role?
3
votes
1answer
507 views

Displaying nucleotide at a single position from RNA-seq reads in a BAM file

How do I display a single nucleotide position from reads in a BAM file? I have been looking at variation using samtools mpileup, but I want to actually just display the nucleotide at the position I am ...
7
votes
1answer
4k views

Why does RNA adopt an A-form helix?

RNA is known to form an A-form helix, while DNA generally forms a B-form helix under physiological conditions. From left to right: A-form DNA, B-form DNA, Z-form DNA. Image created by Richard ...
3
votes
1answer
260 views

Where does meiosis II of oogenesis end exactly in tuba uterina - uterus?

I know that metaphase II ends at ampulla tuba uterina, but I am not completely sure where the telophase II ends. Is it in the triangular section of cervix uterii? I just have an intuition that the ...
17
votes
1answer
696 views

ATP cost for gene expression

How would you estimate the number of ATPs required to transcribe, export and translate a single eukariotic protein?
5
votes
1answer
141 views

What are the constraints when growing an artificial brain?

Are there any experiments on growing artificial brains from brain tissue? What are the constraints? Will such tissue grown to the mass greater than that of human brain surpass it in intellect or it ...
11
votes
2answers
454 views

Antibacterial hand soaps (and related products); what are they good for?

From Wikipedia: Household use of antibacterials in soaps and other products, although not clearly contributing to resistance, is also discouraged (as not being effective at infection control). ...
10
votes
1answer
258 views

Is the minicolumn the unit of the neocortex?

There are many arguments for what the unit of the neocortex is. "Columns" seem to be the standard, but what exactly those are is extremely contradictory between individuals, cortical regions, and ...
7
votes
1answer
128 views

PDB Mining: Why Do I Find Atoms Less than 1 Angstrom Apart?

I am attempting to find potential Hydrogen bonds between Hydrogen donors and aromatic ring acceptors. I do this by predicting the location of Hydrogens on residues and then calculating how far these ...
5
votes
1answer
773 views

Do eye muscles relax when you close your eyes?

I wonder whether the eyes muscle relax when you close them. Common knowledge told us the eyes muscle get tense when you stare at nearby object. If you close your eyes, you eye lids have 0 distance ...
9
votes
1answer
165 views

Is it correct to regard archeaic humans (i.e.n Neanderthals and Denisovans) as distinct species to Homo sapiens?

There is increasing evidence (e.g. here) that Homo sapiens interbred with contemporary homonins such as Homo neanderthalensis and the "Denisovans". Although these homonins do show differences in their ...
12
votes
4answers
411 views

Questions to ask to a panel of people that will be sequenced

Some genes have been shown to be associated with left-handedness. Working with some clinicians, I've recommend them to ask their patients (whose genome will be sequenced) if they are "right or ...
5
votes
1answer
1k views

What is the distinction between F' plasmid and R plasmid?

Is there a difference between an F' plasmid that has taken up a chromosomal gene that conveys antibiotic resistance, and an R plasmid? Is a bacterium containing an R plasmid and yet lacking an F+ ...
12
votes
1answer
568 views

Sequencing the genomes of polyploid organisms

I've done some transcriptomics work in the past with a polyploid organism, and this presented some unique challenges in the data processing and analysis. Since then, I have been brainstorming about ...
4
votes
2answers
2k views

How would a plant sprout and grow in a zero gravity environment?

Have any experiments been carried out involving sprouting and growing plants in a zero gravity environment? If so, what was the outcome? How did the plants sprout out of the soil without gravity? Did ...

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