3
votes
3answers
2k views

How did this spider evolve to mimic exactly a human face and arms?

So I came across something terribly amazing today, that is, a video showing this species of peacock-spider, that literally, transforms into a human face waving his arms about. What could have ...
3
votes
1answer
163 views

What is range of the number of individual organelles in cells

What is the range of the number of individual organelles in a cell? I am not a biologist but I understand that there's one nucleus and sometimes lots of mitochondria, so I am after the total number. ...
2
votes
1answer
417 views

Strange behavior of a DNA gel

I ran a PCR product of ~300 bp on a 2% TAE-agarose gel for 30 minutes. I used Sybr-safe as a DNA stain. Voltage was 80V. When I imaged the gel, the DNA on the bottom half of the gel, including the ...
6
votes
2answers
4k views

Why does plucking nose hair cause tears in the eyes?

It's not a particularly sad or painful thing to pluck a few nose hairs, but it's common for the tear ducts to wet up when doing this. I would like to know the physiological reason for the ...
1
vote
1answer
280 views

Parthenogenesis in Bees

Parthenogenesis is defined as: "A type of asexual reproduction in which egg develops without fertilization to form a new individual." If parthenogenesis takes place in bees, a drone or male bee is ...
1
vote
1answer
185 views

Why does contracting the iris allow less intense light to go in?

The iris contracts automatically in the presence of bright light. This makes a flashlight appear bright in darkness, but outside in daylight you can't even see it's light. The iris is changing your ...
2
votes
2answers
703 views

How prevalent is Taq polymerase in adding 3' A overhangs to the PCR product?

I am conducting a mutagenesis on a gene in vivo of which I need to ligate into an expression vector. The primers I have designed overlap restriction sites of which I plan to use to ligate into the ...
0
votes
1answer
428 views

Definition of Dye- Reduction Test?

Can some one give a simple explanation or definition on what a dye-reduction test is.
5
votes
1answer
301 views

Are there eukaryotes without introns?

This question on the function of introns in eukaryotic genes made me think: I know that more basal organisms have smaller introns and fewer alternatively spliced exons compared to mammals. But are ...
6
votes
3answers
886 views

What percentage of protein isoforms have different functions?

I am looking for studies on how many protein isoforms have different functions, preferably in human. We know that a great many, if not most, of human genes are alternatively spliced and that many ...
2
votes
1answer
143 views

EGFR, sialylation, and cancer progression

EGFR (epidermal growth factor receptor) has been intensively studied in cancer and treatments have been developed to inhibit EGFR signaling. Sialylation of EGFR is known to block dimerization and ...
1
vote
1answer
459 views

Why does the hydrolysis of ATP increasing entropy increase the Phosphoryl-­‐transfer Potential?

I am currently taking a biology class. I do not understand this concept. I understand that the electrostatic repulsion of the negative charges, resonance stabilization and hydration stabilization all ...
10
votes
1answer
734 views

What is the gas inside a Capsicum pepper, and how does it get there?

Every time I make fajitas, I cut into bell and chili peppers and notice how hollow they are. I always think to myself: what is the gas inside this pepper, and how does it get there? Perhaps Capsicum ...
3
votes
1answer
54 views

In which month should I map maritime vegetation?

I'm studying habitat use by Brent Goose in the UK, a species that feeds on maritime vegetation. It's main food types are Zostera sp., Ruppia sp., Ulva / Enteromorpha sp. and Puccinellia sp. I plan to ...
0
votes
1answer
34 views

How Common are Paraneoplastic Syndromes in Cancer Patients?

I recall reading around one in four cancer patients will suffer a paraneoplastic syndrome during the course of their illness but I can't find where I read this and I can't find any reliable sources to ...
4
votes
1answer
813 views

Why Do Nerve Signals Get Crossed?

First off, I don't know if this is a normal healthy thing to occur. There have been many times where I have an itch on say my arm and I scratch it, only to feel the scratching elsewhere on my body. I ...
4
votes
3answers
197 views

Is it technically possible to make someone see something when their eyes are closed?

I'm writing a little article and need any information about how human vision works and latest technologies and discoveries around. Actually its not a professional article. Its for a group of my ...
0
votes
1answer
99 views

Which Enzymes Catalyse the Deacetylation of Drugs in the Human Body?

If you would like more specifics seeing how I realise that this question is very broad and may be difficult to answer in general then hopefully the following will help you out: I am particularly ...
3
votes
1answer
267 views

How might gene clusters like the lac operon evolve?

The obvious answer for a gene cluster is gene duplication and mutation of one or both genes. But the genes in the lac operon seem not be so functionally/structurally similar (as compared to the Hox ...
3
votes
1answer
114 views

205 nm UV-Vis readings

Typically we determine the concentration of proteins using a 280 nm reading. However, it is reasonable to use 205 nm. I was curious about the effectiveness of this method.
0
votes
1answer
292 views

Least painful way to die

There is a lot of talk about inhumane treatment of animals and how we don't kill them in the proper way. I wonder how much research is done on this subject. What is the overall least painful way for ...
0
votes
1answer
720 views

DNA gel extraction: chemical contaminants

I am performing a gel extraction to purify DNA after a double digest with EcoRI and BamHI. After the gel extraction I need to complete a ligation step before bacterial transformation. The problem I ...
2
votes
0answers
49 views

Onset of Autophagy

Fasting and Intermittent Fasting (IF) have been proven to start autophagy (cellular self-digestion). How long does the average man and woman have to wait for autophagy to begin? Does diet prior to ...
6
votes
1answer
175 views

If life is discovered on another planet, will it likely be classified using the current domain/kingdom/phylum system?

This may be a stupid question showing my lack of understanding of taxonomy, but I was wondering if the current classification system we use contains broad enough categories to include new life forms, ...
1
vote
1answer
52 views

How are geneticists able to isolate gene functions?

As an example, this Scientific American article describes a known area in the dog genome that metabolizes carbohydrates. How is it that researchers are able to determine specific functions such as ...
0
votes
1answer
610 views

What's the difference between life expectancy of cigarette smoker and general population?

Some say that smoking cigarettes will shorten lifespan. By how many years is the lifespan of a typical smoker shortened? What are the common cause(s) of death among smokers? Are there any known ...
1
vote
1answer
365 views

What is the brightest color a light source that only emits blue frequency light can achieve?

Let's say there is a luminous light bulb that only emits blue light, and you (or a camera if you prefer) look at it from a close distance. Will the maximum brightness perceived not have any "white" to ...
1
vote
1answer
102 views

How might IVF (and related technologies) alter epigenetic marks?

I was reading up on KCNQ1, which encodes a voltage-gated potassium channel, and I discovered that it happens to be only maternally expressed. This is regulated by KCNQ1OT1, a non-coding RNA, which is ...
1
vote
2answers
174 views

Effect of zero selection (pressure) on the population health

Evolution naturally produces better features: stronger muscles, teeth and minds. Killing the weakest, evolution wipes defective genes out of populations. The mutations are necessary for advance. ...
1
vote
1answer
49 views

What does “Psychomodulatory” mean in the context of potentially psychoactive drugs?

What does "Psychomodulatory" mean in the context of potentially psychoactive drugs? That is, in this journal article http://www.sciencedirect.com/science/article/pii/S0028390812001931 in the ...
2
votes
0answers
87 views

Is there a Pharmacology Textbook that Satisfies the Conditions listed in the Body of this Question?

The conditions are: As extensive and explanatory as Goodman and Gilman's The Pharmacological Basis of Therapeutics, Twelfth Edition With additional extensive and thoroughly explanatory information ...
4
votes
1answer
2k views

What is immunopanning (vs. immunoprecipitation and FACS)?

I had never heard the term before today. From what I can tell, it's using antibodies to purify a cell population of interest. I would appreciate more details, especially in how it differs from ...
6
votes
1answer
217 views

What is the best way to express two proteins in a mammalian cell?

I have two proteins and I will be preparing a vector with both genes for stable transfection. Each protein will have their own promoter and I will use piggyBac vector to insert a single cassette with ...
2
votes
1answer
123 views

Expanding the SETI initiative to seek intelligent data within DNA sequences?

I've recently read a couple articles dealing with long term data storage, and DNA was suggested as one of the prime candidates for long term storage of digital data additionally, there is this article ...
6
votes
1answer
3k views

What causes adenosine build up in the brain when awake?

Adenosine is an important hormone in sleep regulation. It is postulated that when a person is awake, there is a build up of adenosine in the brain, which inhibits the neurons in the brain, and ...
3
votes
0answers
29 views

A program for cell motility assessment with a batch process function?

Cell motility assessment is a branch of experimental biology or medical science. One example could be an assessment of treatment effects on sperm motility of an animal. The standard procedure involves ...
1
vote
1answer
133 views

What is background binding?

I'm reading a journal article about mitochondrial protein import and it mentions that one of the mutant proteins tested showed background binding with another protein. What the heck is background ...
4
votes
3answers
1k views

How can homosexuality evolve despite natural selection?

I would imagine that the answer to this question would be population control, especially since even if one sibling is homosexual this does not necessarily mean that the other siblings will be too.
5
votes
1answer
427 views

What causes humans to be sleepy?

Is there a hormone or group of hormones that regulates when we feel sleepy late at night, or in the morning? Or is sleepiness caused by some other non-hormonal mechanism? (e.g. pure psychological, ...
1
vote
1answer
99 views

Is stereo olfactory ability restricted to humans?

Most animals I see around seem to have two nostrils - humans, snakes, birds, fish .. and so on. From reading online I see that 2 nostrils provide a stereo olfactory effect. This stereo effect is ...
5
votes
1answer
160 views

What limits the size of fish compared to marine mammals?

The largest extant fish species is the whale shark (Rhincodon typus). With a length of 13 meters and a mass of about 20-30 metric tons, the whale shark is relatively small compared to the largest ...
0
votes
2answers
806 views

More proteins from diet when common cold and flu?

My coach says that I need to eat 1.2 - 1.5 grams of proteins per kilogram when I have a common cold and flu. I normally eat one gram of proteins per kilogram, while double it when doing my exercise ...
6
votes
2answers
14k views

What could cause hairs to gray at the tips but not the roots?

I have noticed that some of my sporadic gray hairs are gray at the tip side but oddly, not near the roots. Some are even only gray in the middle. I find all of this very counter intuitive, and I ...
1
vote
1answer
39 views

Did the Swedish cod fishery expand in the past years?

The Marine Stewardship Council states that the cod fishery in the Eastern Baltic sea recovered well and issued it's MSC certificate to the Swedish cod fishery in 2011 for that region. (MSC 2011) Data ...
2
votes
4answers
196 views

Why do some people find vegetables so repellent when evolutionarily they should find them an attractive and thus tasty food?

Why do certain people (especially kids) find vegetables so "repellent" when evolutionarily they should find them an attractive and thus tasty food? I ask this question because if Darwin's theory of ...
2
votes
1answer
213 views

One flybase gene number (FBgn), many Affymetrix Id's

I am trying to convert a set of Affymetrix ID's, like this one 143053_at_3745, to Flybase Gene Numbers (FBgn) like this one FBgn0000015. I have downloaded the Flybase file required to do so (as ...
6
votes
1answer
409 views

Why human cannot stand still in one place?

When a human stands in one place, he cannot stand still but we can see the body slightly swings. Is this due to the Earth rotation or it has something with biology and muscles relaxations? I have ...
5
votes
2answers
533 views

What metabolic activities are performed by a developing human fetus's liver?

I understand that organ function varies with the stages of development. Does a fetal liver EVER perform lipogenesis, gluconeogenesis, make bile, etc? Or does it only begin performing these actions ...
4
votes
1answer
61 views

Do kidneys have the enzyme 3-ketoacyl-CoA transferase?

I am thinking if kidneys can use ketone bodies as fuel. Ketone bodies are water-soluble so no problem because of solubility. The existence of the enzyme determines the answer. Can kidneys use ketone ...
2
votes
1answer
493 views

What controls the breast size?

I am not a biology student, just a curious person. To be specific, I'm talking about humans and specifically about females. I know that it might apply to other mammals. What controls the size of ...

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