All Questions

3
votes
1answer
118 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 ...
1
vote
0answers
43 views

Book about Capillary Electrophoresis of DNA [closed]

Could anyone advise book with a complete description of the mathematical model of CE? Thanks
4
votes
1answer
48 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 ...
1
vote
0answers
19 views

activate a drug using deoxycytidine kinase in vitro

I need to activate a drug similar to the way it is activated in the cell. My set of molecules called Nucleoside analog reverse-transcriptase inhibitors (NARTIs or NRTIs) need three phosphate groups to ...
2
votes
1answer
113 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
278 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
46 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 ...
1
vote
0answers
22 views

Looking for detailed nutrient/energy flow at the bottom of the freshwater food chain

I am trying to model the production and consumption of nutrients and waste at the bottom of the food chain in freshwater ecosystems. I can only find broad information on the Internet and don't know ...
0
votes
1answer
66 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
187 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
129 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
219 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
68 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
37 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
901 views

How many species did Carl Linnaeus classify?

How many species did Carl Linnaeus (senior) classify?
3
votes
1answer
88 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
34 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
161 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
379 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
96 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
137 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
299 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
40 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
39 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
620 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
144 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
46 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
138 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 ...
1
vote
0answers
39 views

Is the white structure on the break of bananas or watermelones sugar?

Does the central part of watermelon or banana have a higher concentration of sugar (fruit-sugar or saccharobiose)? The center of the fruit is sweeter than other red parts of watermelon. In bananas, ...
7
votes
2answers
327 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
169 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
388 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
128 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
64 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
29 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
128 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
325 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
123 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
5k 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
176 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 ...
1
vote
0answers
186 views

Does sexual arousal inhibit functions of prefrontal cortex in human females as well as males?

I've read somewhere, that when a human male experiences sexual arousal, his prefrontal cortex and, hence, his ability to reason and make rational decisions, is being heavily inhibited. Sounds pretty ...
1
vote
0answers
264 views

Size order of human organs

Wikipedia states that the liver is the largest internal organ in the human body. How does it relate to the sizes of ex. the lungs and small intestines? I've been having this personal image for years ...
2
votes
3answers
1k views

What organs are absolutely needed by the human body?

The title is my question: what organs are absolutely needed (fatal if injured/removed) by the human body and perhaps animals in general? I'm not asking which organs are mechanically replaceable, but ...
0
votes
1answer
88 views

Could a person become physically transgender through artificial means?

Let's say there's a girl who carries a few masculine traits not normal in most girls, such as a high level of testosterone; we know there are countless reasons why something like this could happen, ...
-3
votes
1answer
338 views

What are the long-term negative effects of going without water/food for a period of time [closed]

There are no good answers anywhere. so asking: this is not about days of survival without water. This is about long-term negative effects induced from not drinking water for at least the mentioned ...
1
vote
1answer
218 views

How do animals/plants change for each season?

The question pretty much sums it up. How do animals/plants change for each: Spring, Summer, Autumn, and Winter? A detailed explanation on distinct behaviour and appearance changes would be nice.
1
vote
2answers
148 views

Hardy-Weinberg Equilibrium: To compute probability of finding two siblings (random mating)

I've been working a little with M. G. Bulmer's Principles of Statistics (Dover, 1979) and cannot see how to properly compute half of one question. This should be a basic probability computation, but I ...
1
vote
2answers
926 views

What chemicals and structures control the *direction* of plant growth in leaves, stems and roots?

If you want a specific plant, let's say the snap peas I am growing that I bought at Agway. I noticed that they grow towards the light source through the nearby window. Also I think roots work the same ...

15 30 50 per page