2
votes
1answer
405 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
32 views

Avian Diseases : How to Disinfect [closed]

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
516 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
58 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
119 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
90 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
95 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 ...
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
291 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
44 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
392 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
60 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
120 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
100 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
554 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
53 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
57 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
241 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
211 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
198 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
400 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
402 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, ...
2
votes
1answer
114 views

Why is elevated homocysteine considered a risk factor for angina?

Elevated homocysteine levels are listed among risk factors for angina. How is homocysteine related to the heart? Or the coronary arteries? How do these relationships make it a risk factor for angina? ...
9
votes
1answer
144 views

Protein data bank syntax: Can two protein secondary structures “overlap”?

I have a technical question regarding the syntax in Protein Data Bank files. In the protein with PDB# 1AE9 (pdb file), there are two lines in the .pdb file: ...
2
votes
1answer
310 views

Ammonia smell after physical exercise? What is the explanation? [duplicate]

After exercising vigorously one can sometimes smell ammonia and it feels like it's coming from within the nose actually. There is no indication that others can smell it when I do (i.e. seems to be ...
4
votes
1answer
332 views

What causes instinctive behaviour?

Some actions, almost behaviour, exist that are common across a species. For instance, based on personal observation, human babies try to taste anything new they encounter until they are a few score ...
6
votes
2answers
19k views

What is the function of the RNA primer in DNA replication?

During DNA replication, RNA primase puts an RNA primer in the lagging strand. What is the function of this RNA primer? Why can't the enzymes put DNA fragments directly?
3
votes
2answers
667 views

Does finite rate of increase depend on mortality of individuals in a population?

As written in my lecture handouts, there two main factors in the Geometric Growth Model of populations: $R_{0}$ is the expected lifetime reproductive output. This way, for unicellulars, for example, ...
6
votes
1answer
479 views

What happens to an ant colony when the queen dies?

Does the colony collapse? Do workers keep following the last orders? Or can future queens replace the dead one? I'm guessing this might also depend on each specific sub-species.
2
votes
1answer
113 views

What kind of mushroom(?) is this?

I found groups of these growing in the Lassen National Forest (Susanville, CA, USA). It looks like some sort of mushroom. I have Googled extensively, but can't seem to find a match.
2
votes
0answers
52 views

Why do conker flowers grow upwards?

Most trees I know that have their flowers in groups hang these groups down. I noticed, however, that conker flowers grow upwards! I guess that growing against gravity requires special effort, so ...
3
votes
1answer
1k views

How do liver and lung metastases cause death?

Metastasis to the liver and lungs are the main causes of death in colorectal cancer.(1) I understand that colorectal cancer may have metastases. But how do these metastases cause death? Reference ...
6
votes
1answer
127 views

Why does getting certain chemicals in cuts hurt?

More specifically, shampoo. What are the mechanics of detecting a noxious chemical stimulus in terms of which receptors recognise what, how do they do it, and how is this information relayed to the ...
1
vote
0answers
35 views

Are there precedents for considering that the coral reef biome has higher biodiversity than rain forests? [closed]

I've found conflicting references on which biomes are the most biodiverse ones. Also, which are the measures of biodiversity? Average number of different species per volume?
8
votes
2answers
105 views

Where can I find historical data on world-wide ecology parameters?

I hope this is the right StackExchange forum for such a question. I'm looking for large data sets on world-wide ecology parameters, such as annual temperatures by latitude, annual rainfall, CO₂ and ...
5
votes
2answers
295 views

What medical and commercial proteins are made using genetically modified animals?

Recombinant technologies in micro-organisms being used to produce commercial and medically useful proteins like insulin are fairly common. However some proteins are still produced commercially in ...
5
votes
1answer
248 views

Experimental evidence for the selfish gene vs. the selfish individual

In the Selfish Gene, Dawkins makes the argument that a better view of evolution (i.e. more in accordance with experiment) is obtained if you view the basic unit of evolution to be the gene rather ...

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