3
votes
1answer
146 views

What is the use of shampoo; is it for the hair or for the scalp?

Apologies for the confusing question; I did not know how to better ask it. I was doing a search on wikipedia when I found this statement. Wikipedia's entry on hair states; "The hair that is ...
3
votes
1answer
993 views

Does human eye lens have a magnification of its own?

I have always wondered if the lens in our eyes have any sort of magnification by default. And if yes, if we're actually seeing everything around us bigger/smaller than what they actually are! Has any ...
3
votes
1answer
79 views

Does isolation have any effect upon mouse behavior?

I work with a lot of mice. I don't do any behavioral analysis, I just inject DNA or RNA and do imaging assays. However, I have noticed some effect of isolation on mouse behavior. Normally, the mice ...
3
votes
1answer
330 views

What is the best current understanding of how yeast transformation works?

I would like to get myself up to speed with what is currently known to science about yeast transformation. Specifically, transformation of plasmids and linear DNA fragments. I am particularly ...
3
votes
2answers
957 views

Does osmosis take place in prokaryotic cells?

As far as I know, osmosis occurs in Eukaryotic cells, and I'm wondering if it could take place in prokaryotic cells too.
3
votes
1answer
5k views

What is the ratio of breathing rate to heart rate?

Breathing rate and heart rate are directly connected. This is because the heart is connected to the lungs via the pulmonary artery. I first thought that breathing rate would be half of the heart rate ...
3
votes
1answer
671 views

Mitochondria - are they really separate organisms that once merged into eukaryotic cells?

Theoretically, mitochondria are said to be a separate organism that is concerned with its own life and its own processes. In fact, it even duplicates individually. I know a similar question is here ...
3
votes
1answer
59 views

Can a plate with incompletely filled LB agar be used?

I am falling short of LB agar plates and I have a plate with less LB agar poured. I meant, the plate is not fully filled with the agar (it was the last plate I poured the medium into). Some part of ...
3
votes
1answer
285 views

Consumption of NAD+ in glycolysis

Out of 10 steps in glycolysis, only one reaction- Glyceraldehyde 3-phosphate (G3P) to 1,3-bisphosphoglycerate (PGP), uses NAD+ and thereby producing NADH. Furthermore, this very step is solely ...
3
votes
1answer
268 views

is it necessary that every theca of an angiospermic anther must contain two microsporangia

i basically don't know the procedure or sequence of steps involved in the formation of anthers but i have read it somewhere it is formed from the dedifferentiation of shoot apical meristem of the ...
3
votes
2answers
618 views

Animal altruism?

My first impression of http://www.youtube.com/watch?v=Za4uT1ob8qE is that the baboons were being altruistic and benevolent, but is this guess proven or affirmed by science? I sense there's more to ...
3
votes
1answer
125 views

what would be the scientific name of this variety of dove

recently i came across a small dove who had its feathers tied by a rubber band so that it $would'nt$ fly. it looks some what like this i was stunned by seeing it as i have never seen a dove in ...
3
votes
1answer
132 views

How common is it to be pregnant with periods?

As you may know, some women claim that they have their period while they are pregnant. In the arab world they call it "Deer pregnancy", since when the deer gets pregnant, it still gets its' monthly ...
3
votes
1answer
360 views

Are there any air-plants with parts that are edible for humans?

Are any air plants (Tillansia sp.) safe for humans to eat? I haven't been able to find whether or not there are. Pineapple is in the same family (Bromeliaceae), but isn't an air plant.
3
votes
1answer
31 views

Regarding apoptosis and inhibitors

If there is an apoptosis shut-off mechanism of any kind, one could call it a null-apoptosis mechanism. If this is possible, could there be a null-apoptosis inhibitor? Something that inhibits an ...
3
votes
2answers
152 views

The move from RNA to DNA and the necessity of reverse transcriptase

In this piece about giant viruses and the origin of life, in the context of the move from RNA world to DNA world, virologist Valerian Dolja states: In order to move from RNA to DNA, you need an ...
3
votes
1answer
82 views

If two definitive ovums are fused will they form an organism?

Pretend that somehow in a laboratory two definitive ovums (finished 2nd miotic divisions) are are fused together. Will they form a new species?
3
votes
1answer
117 views

Is it possible to get infected with HIV from old blood?

Let's say that someone uses a needle which has some old blood infected with HIV. In this case, is it possible for them to get infected with HIV?
3
votes
2answers
184 views

How is information sent from limbs to the brain exactly?

Say you have a needle, and you poke a very specific area on your left thumb. A signal gets sent from that nerve up your spine and into your brain. How does the brain know exactly where this signal ...
3
votes
2answers
304 views

How does guanidium denature DNA?

Guanidium salts like (G-isothiocyanate) disrupt the hydrophobic interactions inside a protein or nucleic acid and denature it. What happens when hydrophobic interactions in DNA are broken? (I don't ...
3
votes
1answer
2k views

What is the biological function of nose hair?

What is the biological function of nose hair? In general, can we consider underarm hair and pubic hair to be vestigial structures?
3
votes
1answer
166 views

How does the counter current mechanism concentrate urine?

The movement of ions like sodium into the interstitial space causes water to passively diffuse out the descending loop of Henle. How does this concentrate the urine? The solvent is removed at one ...
3
votes
1answer
414 views

What do the Clustal Alignment Symbols Mean?

Occasionally I will run protein alignments on peptide families and I can never remember what the symbols mean to show degrees of identity. What do they mean?
3
votes
1answer
100 views

Biological advantage of electric synapses

Electric synapses are synapses that do not process information but simply foward one action potential from one neuron to the next. There are no neurotransmitters, no inhibitory and exitatory ...
3
votes
1answer
7k views

What is a suicide plasmid?

What is a suicide plasmid? Example: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2737453/ mentions a "suicide vector". See also ...
3
votes
1answer
164 views

Is there a hormone combination that makes humans grumpy?

Imagine a typical situation that is likely to give rise to a bad temper within an individual: a person is awoken very early in the morning by a sound of a lawn being mowed next door. Unlike expected ...
3
votes
2answers
164 views

What species is this worm? [closed]

I was at the park lying on the grass and its the third time I have seen them, I used to think they were parasites when I was like 7. It is the very small brown worm on the green leaf. It moves by ...
3
votes
1answer
112 views

Inbreeding depression and dominance

From this article, second paragraph of the second page A classic theoretical result is that the mean of a character controlled by a single locus i with two alleles Ai1 and Ai2 is only affected by ...
3
votes
1answer
514 views

How does chromosome cross-over occur?

I have heard that during meiosis, homologous chromosomes from each parent "cross-over", which enables the off-spring to inherit some alleles from the mother and some alleles from the father. The ...
3
votes
1answer
601 views

Why basement membrane thickens in diabetes mellitus?

Untreated diabetes mellitus may lead to blindness and kidney failure because the basement membrane of small blood vessels in these organs thickens due to increased production of collagen and laminin. ...
3
votes
1answer
116 views

How does regurgitated food go to the 3rd stomach chamber instead of going to the 1st?

Ruminants are known for their regurgitation of food; the food goes through the 1st and 2nd stomach chambers, then returns to the oral cavity in cuds. The cuds then come back into the stomach, but this ...
3
votes
1answer
53 views

Number of autoregulation and FFL motifs in a network

Suppose we have a network with N* nodes (N* is the number of internal nodes). Every directed link in this network exists with probability p. What would be the number of: motifs that are ...
3
votes
2answers
709 views

How was the Huntington's disease gene's location found?

I read in the book "Why we get sick." by Nesse and Williams that: Steady detective work and fabulous luck have enabled geneticists to pinpoint the Huntington's gene on the short arm of ...
3
votes
2answers
56 views

Tapeworms and their effect on humans

I've read that some people in some countries actually use tapeworms as a form of losing weight. What are the dangers to these people?
3
votes
1answer
149 views

How does sepsis affect heart function?

I have intuition that sepsis with infection can cause: spastic functioning of heart during systole heart working spontaneously in snatches during systole atrial fibrillation first contraction of ...
3
votes
1answer
1k views

How do I get a brighter DNA bands

I've been trying to a good contrast for my DNA bands, however I haven't been so successful. I've been running the ladders only to make sure I get a good contrast before further experimentation. I ...
3
votes
1answer
72 views

How do B memory cells provide immunological memory? Do they differentiate into plasma cells?

My text book doesn't say anything about how B memory cells actually ensure a faster response the second time the antigen is encountered. My guess is that they differentiate into plasma cells which ...
3
votes
1answer
6k views

Why can't ciliary muscles in the human eye relax like other muscles?

I had laser eye surgery a decade ago, but in recent years my eyesight has become significantly myopic. I consulted an ophthalmologist to see if this was eye strain because I work at computers a lot, ...
3
votes
3answers
159 views

Why do 6-8% of diphtheria patients do not develop natural immunity after being affected?

I am thinking of why some patients do not have natural immunity after exposure to the A-B toxin of diphthria. I think the A-B exotoxin is the key factor causing this disease and should trigger memory ...
3
votes
1answer
80 views

What is the creature with the lowest neuron count that demonstrates cognition beyond reflexes?

I'm under the impression that nematode worms just perform the same scripted actions over and over again in response to specific stimuli. They have 302 neurons. Chimpanzees display problem solving ...
3
votes
1answer
2k views

Is the complement system a part of innate or adaptive immunity

I've been reading about the complement system, as part of the human immune system. The complement system is introduced as part of the article on innate immunity on Wikipedia. This classification makes ...
3
votes
3answers
180 views

Is there a downloadable list of all species along with their traditional classification?

I'm looking for a downloadable list of all known (or better said, online documented) species in this straightforward format, as an example the European Frog: Kingdom: Animalia Division: Chordata ...
3
votes
1answer
690 views

Why does caffeine consumption cause one to urinate more?

What is the physiological mechanism behind the diuretic effect of caffeine?
3
votes
2answers
271 views

How does smoking, an environmental factor, cause cancer, fundamentally a genetic disease?

If cancer is fundamentally a genetic disease, how might an environmental factor such as smoking cause cancer?
3
votes
1answer
55 views

Where can I find a full genealogy of human cell types?

It is said on Wikipedia, that the precursor of blastocyst is a morula, and that the precursor of morula is a zygote. This gives us the part of genealogy tree of cell types. Unfortunately, no full ...
3
votes
1answer
2k views

What is the definition of “dry weight” and “dry cell weight”?

As I understand it, the dry weight of something is its weight minus the weight of its water content. Is this the definition? What about dry cell weight?
3
votes
1answer
60 views

Euthyrodism and goitre

I read in Tortora and Derrickson that goitre is associated with euthyrodism. How is that possible?
3
votes
1answer
75 views

Alternating Ovulation

I have often heard that right and left ovaries alternate in releasing ovum. Is it always true? What controls this rhythm? Is it simply because the other ovary is unresponsive to LH or FSH? If so, ...
3
votes
1answer
75 views

What is the cause of the spots on this leaf?

On a hiking trip to the Alps I found trees whose leaves showed those spots you see on the picture. I am curious about what the cause is. Higher resolution pictures of front and back side.
3
votes
3answers
89 views

Would Bubling Oxygen Through “Dead Zones” Like A Fish-Tank Make Much Difference?

I am a dilettante when it comes to dead zones. I realize that they vary from fleeting algal blooms to continuous dead zones. For the continuous dead zones it would seem to me that adding a "bubbler" ...

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