1
vote
2answers
63 views

Which X-Y chromosomes have the developmental genes for mammals?

I know that for a given mammal, half the chromosomes come from father and half from mother. This is typically denoted as x-y. I've recently read about "toolkit" genes that control how a cell develops ...
3
votes
2answers
119 views

Highly spherical Radiolaria; does this image accurately depict the organism?

If I understand correctly, Cenosphaera spp. is a type of Radiolaria, which is a type of zooplankton. The following is an image of Cenosphaera spp. is from the supplementary material (Figure S2) of ...
5
votes
1answer
212 views

Why are certain aneuploidies more common?

Certain aneuploidies such as trisomy-21 (Downs syndrome), trisomy-18 (Edward syndrome), Turner syndrome (XO) etc are more common than others. I had a vague thought that it is related to chromosome ...
2
votes
0answers
109 views

What is the mechanism by which Melatonin increases dream vividness and intensity in humans?

I'm looking at the wikipedia article on Melatonin and noticed that it mentions vivid dreaming caused by melatonin. I have the "Melatonin and the Biological clock" pamphlet referenced in the article, ...
4
votes
2answers
415 views

Does bleach destroy RNAse activity, and if so, how does it do it?

I am working with RNA samples, and I'm trying to be very careful about RNAse contamination. I have some questions about bleach, though. Some people say that a solution of bleach is enough to destroy ...
5
votes
2answers
2k views

Is wiping with RNAse Zap enough to destroy RNAse activity?

From the RNAseZap MSDS, it is an SDS at some unknown concentration, maybe with some NaOH? Some other links suggest there is some NaOH as well. The Ambion site states that RNAseZap destroys RNAse ...
0
votes
2answers
180 views

Recent and good quality articles on systems biology [closed]

I'm a biotechnology student and I have to write a sort of non-experimental thesis (30 pages long) within the end of a three years study. I'm very interested in the "systems biology" field and I'm ...
0
votes
0answers
134 views

How do cells slowly degrade 5,5'-dibromo-4,4'-dichloro-indigo?

5,5'-dibromo-4,4'-dichloro-indigo is the product of X-gal cleavage, often used as a reporter with B-galactosidase. I've made the (unreferenced) observation that it seems as though the blue product ...
2
votes
4answers
130 views

Are there more descriptive ways of naming genes and gene interactions?

I couldn't help but notice just how non-descriptive the gene names that modern genetics is using. Currently I'm reading "The new science of Evo Devo" by Sean B. Carroll and here are some examples of ...
0
votes
1answer
88 views

How can I clean phenol extracted RNA?

I extracted RNA from skin and quantified it in an Nanodrop machine. The 260/230 ratio was very low and two peaks appeared in the absorbance curve, but the RNA is ressuspended in RNAse free water. How ...
2
votes
1answer
72 views

What is the name of the baboons that live in Saudi Arabia

In Saudi Arabia there are a lot of baboons in the mountain area. I would like to know what's the name of this specific baboons so I can read about them more:
4
votes
1answer
1k views

Why does blood come from mouth when people are shot in the chest area?

In almost every movie scene when a character is shot in the chest area, some blood comes from his mouth or sometimes even coughs blood before he dies. Are these kind of scenes realistic/possible? If ...
3
votes
1answer
139 views

Are any organisms known to use meiosis I to create non-identical offspring asexually?

So, there are numerous species of animals who use parthenogenesis, but to my knowledge the reproduction is clonal. That is, the offspring are identical to the mother. Are there any documented cases ...
4
votes
1answer
51 views

What is meant by “alien” probe in a microarray?

In my lab we did a microarray to analyze differential gene expression in S. cerevisiae treated with UV irradiation. We are now analyzing the results and one of the up-regulated genes is labeled ...
2
votes
1answer
128 views

Why is herpes virus neurotropic?

A neurotropic virus is a virus which capable of infecting nerve cells. Herpes simplex virus (HSV) has low neuroinvasivesess and high neurovirulence. HSV is transmitted in vesicle fluid, saliva and ...
3
votes
3answers
1k views

Histidine aromaticity

I understand that the imidazole ring in histidine is aromatic. I also realize that it retains it's aromaticity when protonated. I am wondering why it is not mentioned at all in basic text books such ...
3
votes
2answers
328 views

Detecting Introns and Exons

I know that when RNA is transcribed from the original strand of DNA it contains introns and exons, and that the introns are spliced out of the strand to provide genetic diversity. However, what I ...
1
vote
1answer
47 views

I'd like to know the name and a few details of a certain time-keeping structure in the human brain

I once heard of this structure on the Discovery Science channel and have since forgotten the name. The details I remember about it were that it is the central time-keeping device for the brain located ...
0
votes
1answer
68 views

qrt-pcr and short fragments

I plan to measure the effects of Tenofovir a Nucleotide analog reverse-transcriptase inhibitors useing qrt-pcr with HIV-RT as the rt enzyme. Tenofovir causes early termination of the reverse ...
2
votes
2answers
220 views

The effects of dust particles

When sun rays shoot through my house from a window, sometimes if the lighting is correct, it will reveal a huge amount of floating particles and dust. Are these particles dangerous to humans if you ...
2
votes
1answer
132 views

can the face of a person be accurately predicted from DNA information?

3/05/creepy-or-cool-portraits-derived-from-the-dna-in-hair-and-gum-found-in-public-places/?utm_source=plus.google.com&utm_medium=socialmedia&utm_campaign=20130503&utm_content=collageartdna ...
4
votes
1answer
236 views

How does MEME compute the background frequency of nucleotides?

I am trying to calculate a log-odds matrix for MAST input, from a position-specific probability matrix for the motif in which I am interested. I would like to know how MEME estimates the background ...
1
vote
1answer
70 views

Resource plant anatomy/lifecycle vocabulary

I've been curious about a lot of vocabulary words in the world of botany. I've had quite a bit of trouble finding somewhere online to help me out, but I'm having some trouble finding a resource like ...
2
votes
0answers
38 views

Example(s) of reduced rate of mitotic progression?

Most species complete mitosis, and in particular the process of chromosome condensation, rather quickly, in a matter of minutes. Are there any known species that undergo mitoses with substantially ...
6
votes
2answers
1k views

How many species did Carl Linnaeus classify?

How many species did Carl Linnaeus (senior) classify?
3
votes
1answer
93 views

Low complexity region and relaxed selection

I'm reading a text (Wagner, 2007) on identifying positive selection. In paper, the author says that low complexity regions are known to be associated with relaxed selection. I'm trying to understand ...
1
vote
1answer
35 views

Amount of reverse transcriptase in µg or mM for qRT-PCR

I am trying to calculate a titration amount for a molecule which I would like to use in my PCR samples. Different molecules have different densities so I would like to calculate the appropriate ...
1
vote
1answer
233 views

What is the use of futile reaction cycling such as Fruc-P to Fruc-BP?

One rate-limiting step of glycolysis is the conversion of Fructose-Phosphate (Fruc-P) to Fructose-Bisphosphate (Fruc-BP), catalysed by Phosphofructokinase (PFK). The reaction involves hydrolysing one ...
6
votes
2answers
400 views

Do immortal organisms exist?

Do organisms exist that are able to live indefinitely if they are not killed by external factors? Under external factors I would consider things like predators and natural disaster but not illness by ...
0
votes
1answer
110 views

What does “Activation” refer to in the context of the symptoms of Schizophrenia and Schizoaffective Disorder?

In this journal article certain symptoms are called "activation" in nature. I have never come across this term prior to coming across this article, so I would like to know quite simply what does it ...
5
votes
1answer
145 views

Do lunar rhythms have impact on human biology, if so, how?

I'm approaching this question from the circadian rhythm perspective. A circadian rhythm is a 24 hour cycle. While doing research on deep sea circadian rhythms, I found this abstract which seemed to ...
16
votes
1answer
390 views

Do marine deep sea life forms exhibit circadian rhythms? If so, what entrains them?

I've been reading a lot about circadian rhythms, when suddenly this question popped into my head: do circadian rhythms exist for deep sea organisms (3000 ft / 1000 meters+)? For land mammals, the ...
1
vote
1answer
41 views

glossary of biotechnological engineering

Similar to A good book for history of biology/biotechnology for lay people but not for lay people. Can anyone recommend an advanced dictionary of biotechnological engineering concepts in English ...
2
votes
0answers
40 views

What processes are responsible for focusing on an image only seen by one of the eyes?

When a person is spying from around a corner with only one eye, it's rather easy to ignore the other eye's image, since it's probably much darker, because one usually spies around a corner standing ...
8
votes
2answers
716 views

BLAST DNA Sequences Reversed

I have been trying to learn some basic DNA sequencing techniques and have been using BLAST as a reference. I thought that I was starting to get it, but then I cam across this: It looks like it's ...
2
votes
1answer
158 views

How do you average Ki values?

It's embarrassing for me to ask this but well such is life. NIMH Psychoactive Drug Screening Program (PDSP) Ki Database is mentioned as the source of the average binding affinity (Ki) values given in ...
5
votes
1answer
47 views

What non invasive methods of estimating Body Time are there?

I found this article on estimating body time using molecular timetable of 168 genes. researchers looked at gene expressions and plotted them to 24 hour cosines curve with some pretty spectacular ...
5
votes
2answers
144 views

How is gene expression estimated?

I'm reading this fantastic article on estimating body time: Molecular-timetable methods for detection of body time and rhythm disorders from single-time-point genome-wide expression profiles and one ...
7
votes
2answers
378 views

Why do many fruit trees have five-petaled flowers?

Peach, pear, apple, cherry, and many other fruit trees seem to have flowers comprised of five petals. Assuming there is no evolutionary advantage to confusing students of trees, is there a plausible ...
2
votes
1answer
192 views

Why do I see an inverted image of an object when I close my eyes?

If I stare at an object for a long time and close my eyes, at first I can still see the object with my eyes closed. But the image I see with my eyes closed is inverted: dark colors appear as light and ...
2
votes
1answer
510 views

Using DTNP to find free thiol groups on a protein

I've been tasked with using DTNB to find the number of thiol groups on a molecule of Bovine Serum albumin (BSA). After measuring the absorbance, finding the concentration of TNB and calculating the ...
6
votes
3answers
4k views

What is the distinction between chemokines, cytokines, interferons and interleukins?

They all seem to describe molecules of similar function and many people seem to use them interchangeably. Also please include any other similar molecules if I've forgotten any in the list above.
2
votes
1answer
156 views

What is the mechanism of regulation of PER /CRY genes?

I've read multiple descriptions of biological/circadian clocks and they all mention PER, CRY and CLOCK genes. While I kinda get how they are connected, what interests me is how these actually regulate ...
1
vote
1answer
66 views

Is there a way to see what representations are currently displayed in PyMOL?

I am using PyMol to visualize .pdb protein structures. I show/hide representation a lot, and sometimes I get confused with what representations are currently displayed. So I end up with doing a lot ...
1
vote
1answer
30 views

qTERT-pcr like qRT-pcr

Is it possible to use a biologically active Telemorease Elongation Reverse Transcriptase (TERT) in the place of the Reverse Transcriptase (RT) for quantitative Reverse Transcriptase pcr (qRT-pcr)? Yes ...
4
votes
1answer
133 views

How do mutations come to be shared by all cells?

It's my understanding that various hazards can damage the DNA in our cells, causing mutations. But whenever I picture this, I see the damage being done to one of our tissues (for example, our lungs ...
6
votes
4answers
364 views

Does darker skin color make it easier to live under sun?

I have always thought darker colors absorb more heat from the sun, so if you are wearing a white T-shirt you will be cooler under sun than wearing a darker T-shirt, or a black piece of steel will be ...
2
votes
1answer
131 views

Is there a comprehensive list of human circadian-like processes, hormones or gene expressions?

I'm reading this article onblood sugar and circadian rhythms and the following question popped into my head: a lot of articles mention various diurnal or circadian rhythmicity of biological processes. ...
7
votes
2answers
7k views

Why do dogs try to cover their poop?

It may seem obvious to us humans to hide our excreta, but this is not quite normal behavior for animals. Interestingly, dogs have the habit to pee all over the place. It's know that they do so to ...
1
vote
1answer
206 views

Why are trichromat cone cells unable to sense ultraviolet and infrared radiation?

I understand that cone cells vary in the color they sense, is this because of wavelength, frequency, something else, or a combination of the previous? I also understand that tetrachromats can see an ...

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