3
votes
2answers
116 views

Are identical twins exactly the same?

http://www.scientificamerican.com/article.cfm?id=identical-twins-genes-are-not-identical According to this article some identical twins show differences with respect to their copy number variants. ...
1
vote
0answers
63 views

Harmful effects of radiation from cell phone towers? [closed]

As per this article - http://www.thehindu.com/news/national/mumbai-citizens-link-cancer-to-cell-phone-towers/article5139166.ece , people living adjacent to cell phone towers claim to have developed ...
4
votes
2answers
165 views

Melatonin production - requires nighttime, or just full darkness?

Is melatonin properly produced in daytime sleep in full darkness? Or does it require only nighttime sleep? Additionally, what other biological implications are there, if any, to daytime sleeping? ...
1
vote
0answers
59 views

What are some readily available, easy to test, bacteria?

I want to do a science fair experiment about how bacteria interact with 5-carbon vs. 6-carbon sugars, and I want a bacteria that is easy to test and is readily available. Any ideas?
1
vote
1answer
121 views

What is this awesome plant, which can close its leaves when touched?

I came across this video on Facebook where a plant closes its leaves when touched. Unfortunately the video does not mention the name of this awesome plant. What's the name of this plant, and where ...
1
vote
0answers
21 views

What American textbooks on prescribing guidelines in psychiatry exist? [closed]

I ask this question here because I don't know where else I should ask this sort of question. I know that Maudsley Prescribing Guidelines is a great British psychiatric prescribing guidelines textbook ...
2
votes
0answers
51 views

Critical pO2 threshold for cell division?

I'm a physicist asking questions on an aspect of cellular metabolism, so excuse my biological ignorance! Hypoxia is a frequent complication of certain tumour types, and has quite an implication for ...
2
votes
1answer
8k views

Blood pressure difference while seated and laid down [closed]

My blood pressure readings differ a lot when I read them while seated and while I lay down on a bed. I tie the strap in both cases to my left bicep and rest for a minute before noting the readings ...
4
votes
1answer
55 views

What would life expectancy be in the western world in the absence of Ischemic heart disease?

In 2012, the leading cause of death was Ischemic Heart Disease. In 1st world countries, what is the life expectancy for people who do not die of Ischemic Heart Disease? I'm interested in the USA, ...
1
vote
0answers
35 views

Why must abortive transcription repeat itself a number of times?

Why must abortive transcription repeat itself a number of times before a stable DNA:RNA hybrid containing a transcript of 11 ribonucleotides is formed?
1
vote
1answer
321 views

Why does shaving dehydrate the skin? Is there an hormonal effect involved?

I want to understand why the face becomes dry after shaving and if shaving affects hormones? I've heard that after shaving, hair grows back faster, why? Shaving damages hair follicles and they become ...
1
vote
1answer
102 views

What is the chemical composition of an egg shell?

It ought to be some combination of C, O, and H, I presume. But really why should I care if eggshell gets in my eggs while I'm cooking?
3
votes
1answer
64 views

Difference in reptile inner ear and otosclerosis

In reptiles, the sound is conducted from the tympanic membrane to the inner ear by a single bone. In the disease otosclerosis the stapes of humans become fused to the other middle ear bones( or to ...
2
votes
1answer
124 views

What happens in the synapse when cocaine administration occurs in the human brain

As far as i know when you accept cocaine in your blood some cocaine molecules reach some synapses in your brain and fill some Reuptake tunnels preventing the cell to simply "do not know that fired ...
1
vote
1answer
189 views

What is the effect of extra-cellular potassium concentration on heart rate and conduction velocity?

If the extracellular potassium concentration surrounding a myocyte increases, then the potassium gradient accross the cell membrane decreases, and therefore the resting membrane potential will become ...
0
votes
1answer
62 views

Are grammars for all DNA or RNA of differenent species and individuals the same? [closed]

Are grammars for all DNA or RNA of differenent species and individuals the same ?If so,the languages generated by the grammar are the same,or DNA and RNA of differenent species and individuals are ...
3
votes
1answer
115 views

What would classify those findings of the University of Sheffield experiment as aliens?

It's in the news that some experiment was able to capture some alien specimens during a meteor shower: ...
2
votes
1answer
1k views

How do inward rectifier potassium channels work in the heart?

Apparently in myocytes, there is an inward rectifier potassium channel that operates in phase 4 of the myocyte action potential. I have heard that while this is named as an inward rectifier, that ...
2
votes
0answers
36 views

What's behind the amazing colour combinations in pests & insects?

What's behind the amazing colour combinations in pests & insects ? Do this colour combination signals any character/ poison of the pest/insect ?
2
votes
1answer
39 views

What Biology topics are linked to the Nitrogen Cycle? [closed]

What other educational topics are linked to the Nitrogen Cycle? I am a Science teacher, and I need to organise my lessons. Thanks!
0
votes
2answers
106 views

How is it that the WI-38 cell line isolated by Hayflick in 1962 is still very much around and not affected by the 'Hayflick Limit'?

I have searched the net and I have not been able to come up with an clear answer. Edit: Here is the para quoted from Nature http://www.nature.com/news/medical-research-cell-division-1.13273 "So began ...
5
votes
2answers
735 views

Renin - enzyme or hormone?

Wikipedia says : The kidneys secrete a variety of hormones, including erythropoietin, and the enzyme renin. Can a substance be both an enzyme and a hormone ? Why is renin both an enzyme and a ...
5
votes
2answers
1k views

Which human cells have the longest and shortest lifespan?

Which cells in a human have the longest lifespan? Which cell has the shortest lifespan?
3
votes
1answer
171 views

What happens in your brain when you receive information which causes you to bristle?

I'm talking about moments when you watch a film and you bristle, or when you listen to music, etc. What kind of neurotransmitter flow changes?
3
votes
0answers
97 views

how much grass does a sheep eat in square meters per day? [closed]

I want to buy some sheeps in order to eat my garden's grass. How much grass does a sheep eat each day ??
3
votes
2answers
195 views

Changing the definition of life?

Viruses at this period of time do not fit the current definition of life. Much of the reasoning behind this is that we currently believe that all life must be made up of cells. Also, many ...
2
votes
1answer
250 views

How many consecutive cell divisions are required to form the adult human body from the single cell zygote?

The preferred question would have been what is the total number of cells in a full term human foetus and how many cell divisions are required to reach that number. However estimates of total cell ...
4
votes
2answers
538 views

How does formaldehyde/PBS or methanol fixation of cells affect lysosomal pH?

The question is fairly simple - does formaldehyde or methanol fixation in preparation for immunocytochemistry/immunofluorescent staining affect the pH of the lysosomes? Some background: I'm trying to ...
2
votes
1answer
145 views

GWAS: matched-pairs and logistic regression

Logistic regression is a common analysis tool used for GWAS when your response variable of interested is qualitative. It comes as one of the standard tools in most GWAS packages (e.g. PLINK). Most ...
7
votes
1answer
218 views

On average how many genes / alleles do people share?

I am curious about how much more a child can be alike to one parent than the other. If a child were to inherit all the alleles that are shared between both parents from one parent, but inherit all ...
1
vote
1answer
106 views

Do spouses begin to share genes over time?

I apologize if this hypothesis sounds strange by I was wondering if any research had been done on a phenomenon which I've seen and have corroborated with many other - the idea that over time spouses ...
3
votes
2answers
106 views

Why only heterogeneous SNVs for validation using genotyping arrays?

I am trying to validate the variants I found using whole genome sequencing . The standard practice, I have seen in the two publications below were to check for the number of heterozygous SNPs called ...
7
votes
3answers
126 views

What is the potential function of ultra-conserved elements in the genome?

If selection pressure results in conservation of DNA sequences, what is the most plausible explanation for the existence of ultra-conserved elements (refs here and here) given that there hasn't been ...
1
vote
1answer
167 views

What is the recommended PPM when foliar feeding L-amino acids

It is said that L-amino acids such as histidine, methionine, aspartic acid, glutamic acid, asparagine and glutamine can revert plant stomata closure, increase quality of fruits and assist maturity. It ...
2
votes
1answer
739 views

What happens if an IV drip with a saline solution slips out of the vein, but keeps dripping into the body?

A patient has a saline solution IV drip into the vein. They have somehow moved around and the needle has fallen out of the vein, but remained in the body. Nobody has noticed and for a few hours water ...
0
votes
1answer
39 views

DAT1 dopamine and cocaine binding

I've searched the internet for several minutes and I've looked at DAT but I'm having trouble finding the DAT binding location. Where (and to which aa) does dopamine and cocaine bind to hDAT1?
4
votes
1answer
44 views

A possible cause of autoimmunity

I read that Doherty and Zinkernagel found that MHC- heterozygotes present more antigens to the immune system than homozygotes; yet, the infected heterozygous mice in their experiment all ...
4
votes
1answer
69 views

Why might you NOT observe a tradeoff between two life-history traits?

I have traditionally thought of and heard about life-history traits (e.g., size at first reproduction, number of offspring, size of offspring, survival, etc., etc.) as drawing from a finite pool of ...
2
votes
0answers
58 views

How is Energy Generated in Cats?

I recall reading that much of the energy a cat produces from its food comes from proteins which I assume would produce energy via being catabolised into amino acids which in turn, if glucogenic, would ...
5
votes
2answers
91 views

There are linear and rotary molecular motors in the cells. Do any of them have a fixed or stable frequency or speed?

Are there any linear, rotary or oscillatory molecular motors in the cells which can have fixed frequeny and which can be used as a reference for elapsed time timer? This question is with relevence to ...
2
votes
1answer
71 views

How Do Acid and Base Loving Plants Get Enough PO4?

Acidic and Basic soils experience phosphate sequestration through binding with either calcium, aluminum, or iron. How do plant that thrive in acidic and basic soils obtain the necessary phosphate? ...
2
votes
0answers
65 views

What's the Mechanism of Paradoxical Excitatory Effects with Sedating Antihistamines?

I've been reading the British National Formulary 65 (BNF-65) and it mentioned that in some, especially at higher dosages, sedating (first-generation) antihistamines, can produce paradoxical excitatory ...
2
votes
2answers
965 views

Which hormones can cross the blood brain barrier?

Can hormones such as testosterone, aldosterone and estrogen cross the blood brain barrier? I looked on Wikipedia and there no mention of it in the testosterone article. Through Googling around I also ...
1
vote
1answer
197 views

Number of introns in a genome

Humans have approximately 21000 genes but they probably make more proteins than that. This has been explained by many mechanisms like alternative RNA splicing. My question is - If what we call as ...
0
votes
2answers
49 views

3 fates of this matter

When an animal eats something, it obtains matter and energy right? But, what are the 3 possible fates of the matter and 3 possible fates energy. I don't understand what they are even asking. What ...
5
votes
1answer
227 views

Variations in Genome Sizes

Why is there wide variation in genome size amongst groups of protists, insects, amphibians and plants, but less variation within groups of mammals and reptiles?
1
vote
2answers
40 views

Why don't raisins lose water when in air?

It is common that we soak raisins in water, and they acquire water by endosmosis. That means that the cells are permeable to water, right? Then why don't they lose water when kept in air? Or kept in ...
6
votes
2answers
846 views

What did we learn with Nazi human experimentation?

Was there actually any useful knowledge gained from the Nazi experiments on human test subjects? Wikipedia cites freezing and phosphine gas reactions, but I would like to know other potential results ...
1
vote
1answer
38 views

Variation in MHC in humans

What evolutionary process lead to so much variation in MHC? What is the advantage of having such variation?
0
votes
0answers
14 views

Heart's primary energy source? [duplicate]

Lipids contain more energy than carbohydrates, then why dont our heart start using more carbohydrates for energy deficit? Whats the basic reason for its dependence upon lipids for primary energy ...

15 30 50 per page