4
votes
2answers
59 views

Why proteins are not visible on my membrane after ponceau staining?

I have a problem in western blot that I can't resolve by myself. When I am use to add 100 microgram of proteins for each sample but after running and transfer its impossible to me to see bands of ...
4
votes
1answer
51 views

Can anti-aging cream work?

I have a friend who told me that anti-aging cream cannot work to reduce wrinkles as it only penetrates x amount of skin layers and can never make a long term effect. Me not knowing much about how ...
4
votes
1answer
47 views

DNA sequencing problem

First off, let me start by outlining the problem: Your laboratory has established a technique for examining DNA replication in a cellular extract. To the cellular protein extract, you add ...
4
votes
1answer
212 views

What do trans-fats do when in human body?

Trans fats cause health problems, especially to the heart. https://en.wikipedia.org/wiki/Trans_fat#Health_risks My guess is that all effects happen because trans-fats are inherently toxic as the ...
4
votes
1answer
86 views

Cellular Respiration/Fermentation Problem Leading to Lack of Energy

A young animal has never had much energy. He is brought to a veterinarian for help and is sent to the animal hospital for some tests. There they discover his mitochondria can use only fatty acids and ...
4
votes
1answer
22 views

What's the maximum pressure inside a bombardier beetle?

This question got me wondering about the pressure inside a bombardier beetle. Lots of articles mention pressure, but don't specify the amount of it: One study records the velocity of the spray to ...
4
votes
2answers
59 views

Lyonization vs Genetic Imprinting

Lyonization is the process in which there is inactivation of an X chromosome in females. This process is implicated in mosaic forms of turner's syndrome (in this case the altered ...
4
votes
1answer
63 views

Visualising a subset of the tree of life

I understand that many curated trees of life already exist (eg http://tolweb.org/tree/) but is there any website that allows one to input a list of organisms, and then produce the current best guess ...
4
votes
2answers
72 views

What is a triglyceride?

I'm confused on what a triglyceride is, from what my text book it says its a type of gylercide, then from a website it said Glycerides can be subdivided into two categories. The first group, the ...
4
votes
1answer
31 views

How to measure heat loss in Tardigrades

I want to measure metabolism in tardigrades (a jar of 30 tardigrades). I know that an easy way to measure metabolism is heat loss; I can just measure the temperature of the water before and after a ...
4
votes
1answer
90 views

Length of sleep time

Why do we wake up after 6-8 hours of sleep ? Why don't we sleep for lets say 20-30 hours ? What mechanism is it that controls when to wake us up and how does it determine the moment that we should ...
4
votes
1answer
25 views

Can methylation of a promoter induce gene expression in some rare cases?

Can methylation of a promoter induce gene expression in some rare cases? I've read somewhere that methylation of an intron can induce gene expression (eg. Igf2). How is that even possible? Thank ...
4
votes
1answer
74 views

What effects does being cryogenically frozen have on a person's body? [closed]

I'm wondering what effects are known to happen to a person's cells when a person is cryogenically frozen, especially those that need to be overcome in order to "bring them back to life." From a ...
4
votes
1answer
75 views

A colony of humans are sent to an alien world, at what point would the descendants evolve to be genetically incompatible with Earth humans? [closed]

I recently heard about the evolution of the London Underground mosquitoes, and how they have changed genetically enough that they almost can no longer reproduce with above ground mosquitos. Since this ...
4
votes
1answer
56 views

Are there any known health benefits / risks from milliampere current (0.1-2 mA) on forehead?

This is about devices like that sold by foc.us that allows user to apply a small current on a specific part of the forehead. For the sake of this question I use the foc.us "gamer" model as example. ...
4
votes
1answer
54 views

Do plants have preference for the form of nitrogen as nutrient?

In the nitrogen cycle (ecology), it is usually described that plants can use nitrogen in the form of ammonium (NH4+) and nitrate (NO3-). Do plants prefer one form of nitrogen over the other?
4
votes
2answers
57 views

Is there a command line molecular cloning tool?

There are many softwares such as SnapGene, Geneious, Vector NTI, ApE, Gentle and others for assistance with cloning. Their key functions are: Making maps of plasmids Annotating plasmids with common ...
4
votes
1answer
35 views

A website for identifying birds

I am not sure if this is the right place to ask this question, but I guess that ornithology enthusiasts (or ornithologists) will have the best knowledge about it. I am wondering if there is a website ...
4
votes
1answer
38 views

How can ingesting a prion “infect” someone?

That's something that's been bugging me for a while... Our gastrointestinal tract produces proteases that degrade proteins. Prions are proteins. Shouldn't they be broken by proteases? Also, how can ...
4
votes
1answer
87 views

Mechanisms of extracellular stimulation of neurons

When stimulating a group of neurons with an electrode, let's say we put it in a region that contains axons, what is the mechanism by which the axons are stimulated? I've been told electrodes ...
4
votes
1answer
125 views

How do animals handle light refraction in different media?

For a human, when diving underwater, everything is blurry because of the water's different refractive index compared to that of air, which we are accustomed to. How do animals, like turtles, seals or ...
4
votes
2answers
703 views

What happens when you mix type A with type B blood (and v.v)

What happens when you mix different blood types that are not compatible? For example, if a patient has type A blood and receives type B blood, or v.v.?
4
votes
2answers
384 views

How long does a signal from the brain take to reach the limbs?

If the brain sends a signal to move what's the time it takes the signal to travel via neurons to motor neurons in hands, arms and legs? How fast do those signals travel?
4
votes
4answers
102 views

What bird species is this? (Heron-like waterfowl from China)

I need help identifying this bird. (Some sort of heron?) It was seen in Wuhan, Hubei, China, in September. It is very common there. It can also swim like a duck, but I've only seen it do this once ...
4
votes
2answers
128 views

What governs the size of animal bodies?

Million of years ago there lived dinosaurs up to 36 m high. About 10,000 years ago lived Machairodontinae -compared to cats today they were huge. About 400,000 years ago lived Mammuthus trogontherii: ...
4
votes
1answer
116 views

What is the physiological difference between cortisone and cortisol?

There is only hydrogen bond different. Cortisol is synthesized by our body, while cortisone is given to the patient. Why you cannot give cortisol directly to the patient? I think the reason is ...
4
votes
1answer
52 views

Why can't the immune system start at the mating time?

The immune system has a great role in our body. When foreign particles enter our body, the immune system can recognize and start defense mechanisms such as the complement system and others. But when ...
4
votes
1answer
101 views

What is the most critical step of plasmid purification?

During the process of plasmid purification and quantification, which step is the most critical to the success of the process?
4
votes
1answer
55 views

MHC restricted peptide

What is an MHC restricted peptide? I got this definition from wikipaedia, but cannot exactly extract what the phrase MHC restricted peptide means. MHC-restricted antigen recognition, or MHC ...
4
votes
1answer
53 views

Oxidation means inflamation?

All right, I was reading article on nutrition, that focussed on content analysis of pastry-like food product for kids. I have to say that I am not sure this article would pass the imaginary smell ...
4
votes
1answer
76 views

Influence of temperature on transcription, protein binding and decay rates

I am the kind of biologist who doesn't know much about molecular genetics and about the dynamic of biochemical reactions. Question My question concerns the influence of temperature on the dynamic of ...
4
votes
4answers
127 views

Collective name for the X- and Z-chromosomes

Chromosomes are grouped as sex chromosomes or autosomes, with the X, Y, Z and W all falling in to the former category. The Z and X are present both in the homogametic and heterogametic sexes, and the ...
4
votes
2answers
97 views

Premise of life cycle synchronization between predator and prey

While reading about the predator satiation hypothesis of the periodical cicadas' 13/17 year life cycles, I started wondering about its premise. By the way, I understand the math behind the prime ...
4
votes
1answer
56 views

What is a good identification key for European mushrooms?

I live in the Netherlands, and I am looking for an identification key for mushrooms. Are there any keys you could share?
4
votes
1answer
2k views

Difference between intervertebral and vertebral foramina

In the human spine, what is the difference between intervertebral and vertebral foramina? Is it just a matter of perspective and do they refer to the same thing or are they different?
4
votes
1answer
85 views

Is the heterotroph hypothesis universally accepted?

I was wondering whether there are hypotheses that take a different approach that is contrary to the heterotroph hypothesis. The heterotroph hypothesis states that autotrophs evolved from heterotrophs ...
4
votes
1answer
784 views

why does blood when oxidized over time become bluish green?

Oxygenated blood is bright red and deoxygenated blood is dark red or brown. If you take oxygenated blood and leave it in the air it will turn dark red, then brown, then finally a bluish green from ...
4
votes
2answers
111 views

What is the biological principle of this “holotropic breathwork” technique?

Holotropic breathwork is a non-drug technique developed by Stanislav Grof used in psychotherapy. The therapy as a whole is usually called holotropic breathwork (at least by Grof himself) and will most ...
4
votes
2answers
177 views

How do taenia form a species?

I know that there are many hermaphrodite animals and plants. But many of them seem to still exchange genes by mating with another member of their species. I now happened to read the Wikipedia ...
4
votes
1answer
63 views

How can a plant resist glyphosate (Roundup) herbicide?

In my area, the most common weeds that strongly resists (N-(phosphonomethyl)glycine) (glyphosate) are the horseweed, or mare's tail, Conyza canadensis, and Canada thistle, Cirsium arvense There are ...
4
votes
1answer
93 views

Why do we feel cold on having fever?

Why do we feel terribly cold on catching fever of any sort, however our body becomes hotter? Why is it that a rise in temperature makes the sufferer feel colder? Also, sweating symbolises betterment ...
4
votes
1answer
42 views

Re-solidify disturbed agar plates

I am stuck in trouble while pouring LB agar onto my petri dishes. I had to add kanamycin to my plates just before it started to solidify, out of forgetfulness, which I tried to mix using the tip. The ...
4
votes
1answer
146 views

Start studying mathematical biology from basics

I am really passionate about theoretical and quantitative biology and I would like to build my future career around this topic. I've just got my bachelor's degree in biology (ecology) but scince I've ...
4
votes
1answer
96 views

Question about Monofunctional glycosylases

I am learning about Base excision repair mechanism. I understand the main idea how glycosylases are working, but I am trying to understand this with much more details. I found a paper where they are ...
4
votes
1answer
451 views

Is there any size limit to the amount of information a human (or other) brain can hold

Im not sure how this would ever be tested but is there a limit to how much the brain can 'hold' before it reaches capacity ? I guess this could also be interpreted in terms of memory, as how well ...
4
votes
1answer
125 views

Why are neutral [sterile] female flowers present in inflorescences when they are reproductively incompatible?

In many compound and special inflorescences like spadix and hypanthodium there are sterile female flowers along with male and female fertile flowers and are often present in between male and female ...
4
votes
1answer
114 views

Blosum matrix with probabilities instead of the positive and negative scores

I am trying to find a version of the BLOSUM matrix that has the frequencies instead of the scaled log-odds. i.e. instead of the common version that tells us that the score LEU/ASP is -4, I would like ...
4
votes
1answer
279 views

The parameter for setting the number of mismatches in standalone blast

In a standalone blast search, is there a parameter that could be specified to fix the number of mismatches allowed in an alignment. I went through the parameters and I could only find parameters to ...
4
votes
1answer
133 views

What is this snake

I took a picture of this snake in Switzerland (Geneva Area): It looks to be an adder but cannot be sure about which species. In Switzerland we have two kinds of adder: Vipera berus Vipera aspis ...
4
votes
1answer
183 views

Evolution and the levels of selection

Reading Okasha's "Evolution and the levels of selection" he talks about "the levels of selection problem." There is a bit of a problem with this opening chapter because, while he talks about why the ...

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