9
votes
1answer
120 views

Plumage as indicator of health in birds

Anybody know which traits of bird plumage are accurate indicators of a birds health? For example feather coloration, feather brightness, amount of feather wear, number of feathers, moult timing, moult ...
7
votes
2answers
86 views

Exactly which amino acids are phosphorylated in higher plants during state transitions?

I know it is usually stated as the threonine residue near the N-terminus of either light harvesting complex (lhc) b1 or lhcb2, but if this is somehow lost, say in a mutant, is the system flexible ...
4
votes
1answer
811 views

When is the lactase in lactose-free milk active?

Recently we have started suspecting that one of our children has hypolactasia (lactose intolerance), and so accordingly I have had my first exposure to lactose-free dairy- and dairy-like products. In ...
12
votes
1answer
262 views

Evolution of long necks in giraffes

In this question, the OP uses giraffe necks as a supportive example of evolution. Is the mechanism described in this post accurate? At some point, I thought I remember hearing that giraffes did not ...
30
votes
1answer
793 views

What is itching?

What exactly at the molecular level is itching? What physiological function does itching serve, if any? I cant remember the reference but a PLCb3 null mice lost the itch phenotype, so presumably it is ...
4
votes
3answers
1k views

Is the theory of evolution being disproved by bats?

For some species the Darwin's theory evolution makes perfect sense. I can easily imagine how, for example, the giraffe has evolved to its current appearance: the natural selection was favoring ...
3
votes
1answer
343 views

How does the brain instinctively know the math behind Newtonian Physics?

A 10 year old child does not have the intellectual power to accurately calculate the energy required to throw a ball an arbitrary distance. Yet they are able to accurately throw a ball at a ...
4
votes
1answer
54 views

Where can I find histograms and tables of prevalence of mutations in cancer?

At some point in the past I found a cancer portal site which had aggregated data for the relationships between various mutations and their prevalence in cancer types and tumor data. The data was ...
6
votes
1answer
698 views

Is there a biological basis to physical attraction?

Is there something encoded within us that makes us attracted to, e.g., someone taller or shorter with blonde or brunette hair with green or blue eyes? Or, is this phenomenon completely based on ...
11
votes
2answers
2k views

What is the difference between naive and adjusted p-values in a GWAS study?

What is the difference between a naive p-value and an adjusted p-value in the results of a GWAS study? See from this paper: After Bonferroni adjustment, a single gene, DCTN4 (encoding dynactin 4) ...
10
votes
3answers
254 views

Shortest strings not present in the human genome

What length are the shortest strings of DNA not present in any known person's genome, and what are they? And is there a database online by which I could find this out?
8
votes
1answer
201 views

Why does the gender of the parent species determines the species of a hybrid offspring

I've read a little about hybrid animals, and have been amazed by the fact that the gender of the parent species determine the species of the offspring, in some hybrids. A male horse and a female ...
6
votes
1answer
103 views

What is the biological mechanism linking temperature and probability to be infected with a virus?

It is common knowledge that when you're cold you could get a cold. What is the mechanism linking temperature and viral infection?
3
votes
1answer
441 views

Can parents' learned traits be transmitted genetically?

I am wondering whether a behavioral trait (e.g. fear or stress experienced in the lifetime of the parent) can be transmitted genetically to its offspring? I understand that a behavioral tendency for ...
9
votes
2answers
856 views

Is there any biological reason that professional swimming is dominated by white people?

I suppose that the question should be turned around to "Why is it extremely rare to see black people competing in professional swimming?" because it is the absence of this phenotype while watching the ...
10
votes
1answer
409 views

How would I explain different properties of the same protein in different species?

I recently finished an experiment where I analyzed the rate of ATP hydrolysis of Heat shock protein 104 in three species of fungi. They have shown to all have different rates of ATPase activity. How ...
7
votes
3answers
937 views

Why don't all ants have wings?

Since the new queens-to-be have wings, it means that ants either evolved from insects that can fly, or insects that can fly evolved from ants, or that we have a case of parallel evolution (which is ...
8
votes
1answer
564 views

Do drugs always degrade after they have passed their expiration date?

I have been wondering for some time whether several drugs really have an expiration date. Let's narrow the scope and think about only "common" drugs, e.g NSAIDs, antibiotics etc. For example, would ...
7
votes
1answer
500 views

Do egg laying animals experience a pregnancy?

Does a female animal that lays eggs experience a pregnancy-like period of time, where she will feel and behave differently as if she were fertilized and her body is prepared to lay a fertile egg, not ...
6
votes
1answer
184 views

How is hibernation/aestivation different from anesthesia?

How do hibernation/aestivation happen? I read on wikipedia that a squirrel injected with the body fluids of a hibernating fellow is more prone to hibernation. If hibernation/aestivation are driven ...
5
votes
1answer
68 views

Does a plant have to be alive for its roots to prevent erosion?

One argument often given in favour of saving current and planting additional plants/saplings is the roots hold soil together and prevent soil erosion. Unlike plants that may be uprooted, a large ...
4
votes
2answers
1k views

What is the effect of a pure-oxygen environment on a plant?

Just read What's the effect of oxygen deficit on plants? ; and wondered whether the opposite would have any effect on a plant. That is to say, if a potted plant were placed under a bell-jar and ...
3
votes
2answers
146 views

What is the biological basis for a human's ability to think clearly and be aware while “fighting/competing”?

I'm interested in learning more about the biological systems or hormones or parts of the brain that affect short term (<15 minutes) ability to concentrate attention on the task and be aware of the ...
3
votes
0answers
124 views

What controls the feeling of discomfort/comfort before and after sleep?

I'm interested in which biological systems or hormones are involved in the following phenomenon: Before sleep it may be difficult to find a comfortable position, and muscular aches and pains are more ...
6
votes
1answer
61 views

On the effect of polluted air on health. Is it more gradual, or more immediate?

I've heard time and again that living in São Paulo (a large city in Brasil) takes 1.5 years from your life expectancy. The allegation is that this happens because of air pollution. I am just ...
4
votes
1answer
75 views

Drosophila reference genome

Does anyone know the details about which line they are using to sequence as the Drosophila melanogaster reference genome?
9
votes
1answer
227 views

Black bumps on the cut surface of an avocado

I cut an underripe avocado in half and put half of it, without the pit but with the peel, in the refrigerator. A day later, I see very small black bumps along the cut surface. What are they? What ...
6
votes
1answer
119 views

Macromolecule levels in daughter cells after fission

When a prokaryote undergoes binary fission, how are the non-DNA macromolecules distributed between the two daughter cells? This is motivated by comments on a previous question and a G+ discussion. I ...
4
votes
1answer
110 views

Is there a correlation between incidence of type 1 diabetes and vitiligo?

Does the data indicate that if you have one, the probability of you having the other is higher than that of someone who doesn't have the one?
9
votes
1answer
496 views

Why does this illusion work?

This is another image I found on Google+ All lines are absolutely straight, parallel and perpendicular but why does it appear to have a curvature? Related: How does this illusion work?
3
votes
0answers
69 views

Are mature trees as susceptible to mutation from exposure to radiation as seedlings?

If a plant, say a ficus or a teak, as a sapling were exposed to radiation, and a tree of the same species were present at the same distance, which of the two would be more likely to mutate?
6
votes
1answer
92 views

DNA modifications other than 5-mC/5-hmC/5-fC/5-caC in vertebrate genomes?

Other than 5-Methylcytosine and the more recently discovered 5-Hydroxymethyl, 5-formil and 5-carboxylcytosine DNA modifications found in DNA sequences, what are other DNA modifications present in ...
1
vote
1answer
495 views

Is sperm contagious?

A person may have a cold or any other disease that is an airborne-infection. Is their sperm also contagious? Should the person take any precautions?
3
votes
1answer
48 views

Is there such thing as “biological cycles” of activity/performance/etc in mammals?

I'm looking for some information about the cycles of increased/decreased activity, mental performance or endurance that are related to a mammal's age and the time of a season. First of all, I'm not ...
7
votes
2answers
382 views

How to compute properties of peptides ?

I have been tasked with writing a program for computing properties of a give set of peptides. These peptides are given as 1-letter amino acid sequences and I need to compute the following : Length ...
5
votes
1answer
227 views

Cell proliferation limit and senescence of embryonic stem cells and fibroblasts

I am trying to understand the importance of proliferation limits and cell senescence. In particular, I would like to compare the proliferation limit of Embryonic Stem cells (ES) and fibroblasts (which ...
6
votes
1answer
318 views

Computational/mathematical models for predicting phenotype from genotype

Karr, Sanghvi, et al. (2012) propose a whole-cell computational model for predicting phenotype from genotype in Mycoplasma genitalium. Their model simulates myriad cell processes such as DNA ...
3
votes
1answer
77 views

Text/resource with information on all skeletal muscles and their motor units

Something analogous to an encyclopedia on baseball players with a list of all thier stats would be ideal. I'm not looking for just generic muscle names, locations and illustrations. Good answers ...
3
votes
1answer
99 views

Would a plant survive if it was watered using hard-water?

Hard water is water with high mineral/salt content. I'm told that a potted plant watered with a salt solution dries out sooner or later. Is this true? If so, would a plant survive if watered using ...
3
votes
2answers
235 views

Short-term Lamarckism in asexual single cell organisms

I was reading through the Karr et al. (2012) whole-cell computational model. One of the things they did was to induce single-gene disruptions in their model. They observed several to be fatal, but: ...
3
votes
2answers
261 views

Does body mass have a bearing on reflex speed?

A reflex is an unconscious action in response to some specific stimulus, e.g., blinking an eye, or pulling the hand away from a hot pin I know from school biology, and reading online that withdrawal ...
2
votes
1answer
2k views

What negative effects can pinhole glasses have on the body?

While shopping in the local supermarket yesterday, I was surprised to find this display on one of the shelves. I also realize that I should have taken a pamphlet with me, as well as a picture of ...
2
votes
1answer
783 views

Circulation through the liver in light of drug metabolism

I have a lingering question which stems from an answer that I gave to What hydrolyses aspirin within the digestive tract and blood stream? When a drug or any other substance is absorbed into the ...
6
votes
1answer
261 views

What are the white dots on the tree in this photo?

Today in Kongens Have, I noticed a lot of white dots on bark of trees. There are plenty of them, and they were usually on 'bottom' side of branches. Does anyone know what this could be? I took a ...
9
votes
2answers
138 views

What role does a protein's size have on protein-protein interactions?

Protein-protein interactions are when two or more proteins bind together, possibly for some important biological function. Recently, I'm starting to look more into proteins, and in particular, ...
8
votes
1answer
613 views

A timeline of the odds for survival for fertilized eggs and fetuses

I'm looking for data to build a timeline of the odds for survival of a fertilized egg, i.e., What are the odds it'll last a week? What are the odds it'll last a month? 2 months? (and so on ...
14
votes
1answer
1k views

How does evolution produce complex organs

I've been wondering lately how evolution manages to produce complex organs. It is pretty obvious to me how evolution would select some minor traits like size, resistnce to illness or climate. There is ...
12
votes
4answers
2k views

If body temperature is 37°C (98.6°F), why are most people more comfortable at around 21°C (70°F)?

It may be different for other people, but for me, anything above 32°C (90°F) is very uncomfortable, and my body is inclined to seek cooler temperatures. But I would think that at 32°C, the body would ...
6
votes
1answer
519 views

How and when did a dedicated immune system evolve?

I have recently been doing a lot of research into the interplay between the innate and adaptive immune systems in humans, and mammalian laboratory models. This has led to my reading some interesting ...
4
votes
1answer
98 views

Are there any situations in which phenylephrine is preferred to pseudoephedrine?

In the mid 2000s in the US, due to issues of drug enforcement, pseudoephedrine containing medications were brought behind the pharmacy counter and in most cases require ID, and phenylephrine was ...

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