6
votes
2answers
427 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
122 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
149 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
410 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 ...
3
votes
0answers
44 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
827 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
163 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
48 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
149 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
445 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
200 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
590 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
5k 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
169 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
67 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
138 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 ...
7
votes
4answers
430 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
134 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
226 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 ...
2
votes
3answers
2k 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
117 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
429 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
314 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
180 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 ...
5
votes
2answers
1k 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 ...
3
votes
1answer
84 views

Understanding these SNP annotations

I am looking at the PharmaPGKB database for SNPs and trying to understand what the following annotation means: rs1801131 at 1:11854475 in CLCN6, MTHFR (VIP) Ok, ...
2
votes
1answer
71 views

Why it is so difficult to treat leukemia?

I want to ask what is the reason that T315I type CML leukemia is currently untreatable. I have read quite a few papers in this subject. Why the current genetic oriented engineering drugs failed to ...
6
votes
1answer
603 views

Why dogs move their noses when smelling?

I read on Wikipedia that: The wet nose, or rhinarium, is essential for determining the direction of the air current containing the smell. Cold receptors in the skin are sensitive to the cooling of ...
1
vote
3answers
822 views

Can animals, like monkeys, be homosexual?

I heard that some monkeys can be homosexual? a friend of mine was saying that he saw a male monkey having sex with another male monkey in the zoo, I honestly didn't believe him, I think he just got ...
2
votes
1answer
115 views

Why do ion concentrations change with different secretion rates in pancreatic juice?

Why is it that when secretory rate increases in the pancreas the concentration of chloride ions decreases, and the concentration of bicarbonate increases in the production of isotonic NaCl secretion? ...
4
votes
1answer
533 views

Why do sloths come down from the trees to defecate?

I'm under the impression that most sloths exhibit this behavior, but why? They are slow moving and so have no way of escaping from predators when on the ground. Not to mention the energy they expire ...
2
votes
2answers
163 views

Up to date B cell review

Where would I find an up to date (last 6-7 years max) review on B cells? I've tried searching through pubmed with filters, cochrane library, medline and various other resources including searching old ...
4
votes
3answers
168 views

HIV and T helper cells

As far as I know and could understand from reading about HIV, T helper cell is one of the main reasons to develop AIDS in patients infected with HIV virus, that because the absence of helper T cell ...
1
vote
1answer
701 views

Role of Fbx15 in ES cells and its use in assaying for iPS cells (Yamanaka paper and others)?

I am trying to understand the assay for iPS cells in the Takahashi & Yamanaka 2006 paper. They inserted a beta-geo cassette, which contains the neomycin resistance gene, into the Fbx15 gene. The ...
2
votes
0answers
102 views

Size of classical liver lobule across species

A classical liver lobule is made up of a central vein and the portal triads. A typical human liver weighs around 3 lbs. , while a typical bovine liver weighs around 12 lbs. I was wondering if anyone ...
2
votes
2answers
318 views

What mechanism suppresses melatonin release in humans?

I'm looking at melanopsin, a photo pigment in the human eye. One of its actions is to trigger suprachiasmatic nuclei SCN to suppress melatonin release. I'm interested in learning what is the exact ...
14
votes
1answer
606 views

Why is yawning contagious?

Why does yawning seems to be contagious? Is this similar to laughter being contagious or does it has a different reason?
4
votes
1answer
683 views

How do I view the simulated protein structure along with ligand in VMD?

I did a simulation of a protein-ligand complex, and it has stabilized after 5 ns. I have got the respective pdb files for every ns, but when I try to view in VMD (Visual Molecular Dynamics), I cannot ...
4
votes
3answers
155 views

Results of a complete DNA sequencing - are they 100% reusable?

Is that correct that a complete DNA sequencing (the whole genome) need only to be done once (per person)? After that is done, it the complete genome can be stored and once the new genes (and their ...
1
vote
0answers
71 views

Why do animals sleep [duplicate]

Animals spend a good portion of every day doing nothing, and it seems like that time could be better spent hunting, searching for mates, etc. Also, animals are not aware during sleep, so it would be ...
3
votes
1answer
940 views

How does sugar enter neurons if they don't use insulin?

I heard somewhere that as opposed to other cells, neurons do not use insulin to get their sugar supply. Why is that? What is the alternative mechanism? I assume sugar can't just enter the cell ...
2
votes
1answer
160 views

How long does a tan last?

How long do melanocytes and melanosomes continue to protect DNA after UV exposure? Basically, if skin is tanned, then over the next month it is shed, will melanocytes continue to produce high levels ...
2
votes
0answers
47 views

Can Infant Crocodiles digest Bread? [closed]

I'm just curious as to whether crocodiles and if you require specifics, saltwater crocodiles, could eat bread as infants. I was watching Lake Placid and I was curious as to whether infant saltwater ...
2
votes
2answers
325 views

How to know if a woman is fertile without actually making her pregnant?

How to know if a human female is fertile (can give birth to child in future) without making her pregnant? Any signs, tests?
5
votes
2answers
3k views

What is the function of nodes of Ranvier in axons?

In a neuroscience class I'm taking, it was explained that myelin covers axons in sections, the uncovered sections are called nodes of Ranvier, and signals propagate much faster in the covered ...
3
votes
3answers
4k views

Separating DNA Fragments by Gel Electrophoresis. Are all the strands for one size the same?

My apologies if my question is too basic, and please point me to a more appropriate forum. I am reading the textbook "Essential Cell Biology" by Alberts et al, and am consulting other sources as ...
2
votes
1answer
192 views

Two brown-haired people have two children, P and Q. P has blond hair. Q has brown hair. What is the probability that Q is heterozygous?

Two brown-haired people have two children, P and Q. P has blond hair. We therefore believe that each parent is heterozygous and that blond hair is a recessive trait. Q has brown hair. What is the ...

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