1
vote
0answers
82 views

Is there a biological process which causes organs to atrophy in response to enivronmental stressors?

I am aware of what happens when the body experiences starvation and breaksdown the muscles in the body for protein sources and the other processes that happen in such a scenario. However, i wondered ...
21
votes
2answers
9k views

If a human takes antibiotics are all bacteria in the body killed?

From my basic understanding, antibiotics kill living things, bacteria for example. Do the antibiotics consumed by a human-being distinguish between what they kill? Or do they just kill every bacteria ...
0
votes
3answers
76 views

What are the allowed evolution operators (on protein encoding sequences)?

What are the evolution operators, meaning allowed actions on the DNA sequence that encodes a protein. I assume all evolution of genes is a result of duplication errors. So an answer could look ...
2
votes
1answer
40 views

Are CoA and CoAS the same thing in a compound?

Is CoA-S-R the same as CoA-R, and is CH3C(=O)CoA the same as CH3C(=O)SCoA? Eg. Above is the compound on the right just coenzyme A or is it actually another compound and not just notation?
5
votes
1answer
56 views

What regulates these two methods of splicing?

Alternative splicing can shuffle the exon order and select from the exon sequence of a single gene site to provide a combinatorial selection of possible transcription products from the one gene. Can ...
1
vote
0answers
34 views

Randomized experimental design in genetic experimentation.

I am struggling to find out if randomization is used in traditional genetic breeding experimentation with model organisms, especially in lab contexts? And why this should be so? This is part of a ...
2
votes
1answer
68 views

Autophagy in eukaryotic cells

What is autophagy? How and under which circumstances is it used by the cell? I believe The reason for autophagy is some kind of recycling, am I right? But why does it occur in infections?
1
vote
1answer
121 views

Do nerve cells cause action potential in cardiac muscle?

I think the answer is no, but I am not 100% sure. If it was yes, then the dendrite of the nerve cell should each time receive a stimulus causing Na+ channels to open, when the contraction happen. ...
5
votes
2answers
537 views

Can proteins move outside cells?

I am trying to learn about basic cell biology, and have what is probably an extremely simple question. So this is how I understand it so far: Proteins are made from amino acids. This process is ...
2
votes
1answer
118 views

Can songbirds mimic car alarm sounds?

A silly question. A few days ago I observed a very vocal bird with impressive vocal variety. It was rapidly switching from one tune to the next. After sometime I realized that the bird might be ...
5
votes
1answer
565 views

Is human face more resistant to cold than other body parts?

Walking outside tonight in -15˚C I realized an interesting observation: While I felt cold on most part of my body, my face (although the only uncovered part) didn't really feel cold. It registered the ...
6
votes
1answer
154 views

Does muscle growth trigger angiogenesis?

So heavier people generally have more blood than lighter people (this is why heavier people generally need to take higher doses of medication for the same effect of medication). They also have more ...
3
votes
2answers
609 views

Just how light-sensitive is ethidium bromide?

One lab I was in was paranoid about keeping it in a foil-wrapped conical tube; my current lab leaves it out on the bench (and it works fine for staining gels). It's the same company/concentration in ...
4
votes
1answer
177 views

Plasma cells and memory cells

What decides whether an activated B cell will get converted to plasma cell or memory B cell? Is it necessary that out of a mitotic division one will convert to memory B cell and the other to plasma ...
2
votes
1answer
391 views

Comparing BLAST and the Smith-Waterman algorithm

I've been asked: how does BLAST improve dynamic programming accuracy? I do know that BLAST is based on heuristic approach that approximates the Smith-Waterman algorithm and that the Smith-Waterman is ...
6
votes
1answer
127 views

Same 185th million grandfather?

I was watching a lecture by Richard Dawkins earlier today and he mentioned that “Your 185th million grandfather was a fish.” I started wondering about the following question, Is it true that my 185th ...
1
vote
0answers
30 views

Avian Diseases : How to Disinfect

How can I sanitize a bird's carcass so that no diseases are present after disinfection? I was thinking $\gamma$-ray bombardment since ozonation would only surface disinfect.
7
votes
1answer
57 views

Intracellular lipid transport

I know that lipids are carried around the body in the blood either as micelles or by lipid-binding proteins which allow them to be solved. Lipids can't always be integrated in a membrane though, the ...
1
vote
2answers
489 views

General undergraduate zoology textbook recommendation?

I am very interested in zoology,and I want to study zoology in my spare time. Any undergraduate level zoology text book recommendation?
1
vote
1answer
56 views

What's seen when stress echocardiography shows ischaemia? Can this happen without angina?

What can be seen on the screen when stress echocardiography (a pair of heart ultrasounds before and after exercise) suggests ischaemia? Can this happen without chest pain? Illustration from ...
2
votes
0answers
57 views

Movement of stem cells from mother to fetus

Recent results from J Lee Nelson and colleagues (Sci Am. 2008 Feb;298(2):64-71; available as full text through Google) show that cells from the mother were found in a person aged 46. Logically, these ...
2
votes
1answer
39 views

What are ways to compare the “costs” and “gains” of food production systems?

I'm looking for methodologies to compare the costs a food production requires with the gains it delivers (not in economic terms). I'm aware of energy returned on investment. Are there other methods ...
3
votes
1answer
116 views

How do different tissue culture matrices affect background in fluorescent microscopy?

In response to my previous question, I've been reading up a little bit on poly-D-lysine, Collagen I, Collagen IV, laminin, and other tissue culture coatings that promote cell adhesion. I've always ...
2
votes
2answers
89 views

Evolution after the development of sexual reproduction

My understanding of evolution is that genetic mutation occurs in individual members of a species, and they become a new species. Isn't a definition of species a group of genetically similar organisms ...
6
votes
3answers
168 views

What reasons allow for women to outlive men?

It is a well-known fact that women tend to outlive men. I often hear people unscientifically stating that men generally generally die younger because of the higher stress encountered in their work ...
4
votes
1answer
81 views

Measuring sugar content of a tree

I would like to grow mushrooms on oak trees I can harvest from my property. I've read that the best results will be when the sap is rising but the tree hasn't budded yet. The mycelium feeds on the ...
3
votes
0answers
75 views

Food Intake versus ability to flee among birds, particularly the hummingbird?

Logically speaking, if a hummingbird drinks too much nectar, it will be temporarily overweight and less able or unable to fly to escape danger. However if the same hummingbird doesn't drink enough ...
3
votes
1answer
93 views

Can you cure allergies?

A common solution is allergy shots, which helps you adapt to the allergy. But are there ways to tell the body that this allergy is safe and there is no need to amount a response to it? So that there ...
1
vote
0answers
36 views

Do antidepressants with their BDNF expression-increasing effects display disease-modifying effects in Alzheimer's disease?

I ask this question because I've looked everywhere I can think of and not one mention of this even though it definitely makes sense based on the finding that antidepressants increase brain-derived ...
4
votes
1answer
85 views

What determined the evolution of different faces in humans?

The most distinctive characteristic of a human is it's face - it is unique among each individual (with the exception of identical twins). It is uncertain to me if whether we best identify other humans ...
1
vote
1answer
287 views

How do changes in temperature affect body weight in humans?

What would be effect on weight of individuals if we bring a fully adapted (to cold climate ) human individual and a fully adapted to very hot climate individual to a moderate climate region?
2
votes
1answer
250 views

What is this insect?

These photographs were taken today in Marseille, in the Mediterranean coast of France. My French friends inform me that these beasties are called cousins because they are "cousins" of mosquitoes ...
1
vote
0answers
40 views

What parts of the brain are involved in regulating blood pressure in mammals?

I'm reading this Wikipedia article on blood pressure and its regulation, and it mentions that medulla is involved. however, I vaguely remember reading another article on Wikipedia and it mentioned ...
-2
votes
1answer
379 views

Are we evolving to age slower, or to live longer aging at the same rate?

I wonder why most of us find senior people lovely and charming. Is it because to love grandpa and granny is vital to our survival as a species, in the same way as we love babies? If so, it would mean ...
8
votes
1answer
1k views

How does this illusion work?

I found this image on Google+ If you shake your head you can see a portrait of a person. Can anyone explain how the image is constructed in the brain?
2
votes
1answer
78 views

Identify this waterfowl species?

I've been unable to find anything on the Google resembling this bird. I took the photo in Virginia Beach, VA around 2010, October, I think... It appears to be between winter and summer plumage but I'm ...
0
votes
1answer
58 views

Why is epinephrine not part of the somatic nervous system?

I learned that the adrenal medulla releases epinephrine, which is a vasodilator of the vessels that lead to the skeletal muscle. I also learned that somatic nervous system only uses Achetycholine as ...
6
votes
2answers
141 views

Can any species be bred selectively/engineered to become as diverse looking as dogs?

I've done some research and it appears that dogs are the most diverse looking single species of mammals. The questions that interest me is - are dogs special in respect to genes/gene activation ...
2
votes
1answer
117 views

Does precipitation influence the UV spec reading?

I have been checking my sample for Hydroxyl radical scavenging activity. I have dissolved Hydrogen peroxide in Phosphate buffer. My sample is clear and reagent is also clear but when I have mixed my ...
1
vote
1answer
48 views

Introductory text for primatology

I'm looking for a book that provides a good overview of primatology, one aimed more at researchers rather than a popular science book. Ideally, I'd like something with an ethology/ecology angle with ...
2
votes
1answer
76 views

Do cockroaches eat their shells after moulting?

I recently witnessed a cockroach eat its shell after it moulted. Do cockroaches always do this?
3
votes
1answer
99 views

Would non-human carnivores be able to survive on farmed foods?

Certain creatures that are considered carnivores are non-obligate carnivores and are technically omnivores (such as wolves/dogs). How different is the potential digestive ability of these species ...
2
votes
1answer
537 views

Optogenetics - How do microbial opsins work?

I'm just introduced to the optogenetics method and am having some trouble grasping the genetics (of the optogenteics) part of things. So we have Retinal and Opsin that form Rhodopsin molecule that ...
0
votes
1answer
51 views

What is a good review article source for Physiology?

I am looking review articles for Physiology. For instance, Physiological explanation of steps of measurement of the metabolism by Douglas-Haldane. There is no section for Physiology or metabolism in ...
1
vote
0answers
54 views

Removing bacterial contaminants from resin

We have a few Strep-tactin columns that had some growth in them and we would like to regenerate the columns back since the resin is quite expensive. Basic goal: remove the brown stuff. So far, I've ...
2
votes
1answer
235 views

How do fully dioecious plants determine sex?

I know that a minority of plants are fully dioecious, with adult plants producing either only male or only female flowers. When is this sexual differentiation determined? Is the seed of such a plant ...
6
votes
2answers
208 views

How do infectious bacteria know when their numbers are high enough to attack a host?

When you get sick, you generally don't contract enough bacteria at once for them to succeed in battling your immune system, right? Their numbers must gradually increase in the host's body before they ...
5
votes
1answer
189 views

Is there a practical upper limit to amount of nucleotides or genes in a transformed plasmid?

I'm currently working on a synthetic biology project which involves working with lots of different parts. I would ultimately like to integrate these genes by transforming a single plasmid. I've heard ...
9
votes
2answers
394 views

Does arterial blood always flow away from the heart?

Is there a negative net flow of blood in human arteries at any point of the cardiac cycle? I realise that blood flow can be turbulent, e.g. in the aorta or around stenotic arteries, but then the ...
3
votes
1answer
388 views

Meat and mushroom allergies, why are they so rare?

There are a lot of food allergies, but for some reason not to meat (mammalian meat or poultry) or mushrooms. I've googled a bit, and now I know that one can actually have a meat or mushroom allergy, ...

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