4
votes
1answer
6k views

Does mixing alcoholic drinks really make you more drunk?

There is plenty of anecdotal evidence ("beer after wine and you'll feel fine, wine after beer will make you feel queer") that mixing alcoholic drink types leads to a stronger effect, but I can't find ...
4
votes
2answers
123 views

Ultrasound during pregnancy

In a hospital I can see a long queue of pregnant women waiting for their turn for ultrasound. Is it safe to go through the ultrasound during pregnancy, especially during last few weeks? Is ...
4
votes
3answers
9k views

Evolutionarily speaking, why do humans have 46 chromosomes

In humans, each cell normally contains 23 pairs of chromosomes, for a total of 46. Monkeys, chimpanzees, and Apes have 24 pairs (twenty-four pairs), for a total of 48. What caused humans to have 46? ...
4
votes
1answer
196 views

Why would deers keep crossing a river full of crocodiles while some of them have been killed?

I recently watched a clip on Discovery Channel, where I saw deers crossing a river full of crocodiles, ignoring the fact that some of them would have been killed doing so. What could be an ...
4
votes
1answer
1k views

Is ovum + ovum fertilization possible for human?

In humans is it possible to fertilize a ovum with another ovum from the same female subject? I already found some works in which the ovum is fertilized by a somatic cell (see e.g. this ), but I am ...
4
votes
1answer
3k views

Do humans have Coelom?

Kimball Biology 5e says Coelom is the main body cavity of many animals. It is lined with an epithelium derived from mesoderm. Gilbert Embryonal Biology 9e says Coelom is the space between ...
4
votes
1answer
1k views

How do caspase proteins kill a cell?

Wikipedia just says... The active effector caspases then proteolytically degrade a host of intracellular proteins to carry out the cell death program. Okay, but what parts of the cell do they ...
3
votes
1answer
67 views

Involuntary twitches and apnoea during early phases of sleep

I assume most people either experienced or have seen people with the following phenomenon: in the early phases of sleep sometimes involuntary twitches occur that usually accompany the pause of ...
3
votes
2answers
104 views

Why can't we defibrillate the heart within 1 minute after ventricular fibrillation by electroshock?

We mostly can defibrillate the heart before 1 min of ventricular fibrillation by electroshock.Then we often can't do defibrillate it with electroshock. What's the reason and What's the best way to ...
3
votes
1answer
45 views

Why do the size of the phase 1 notch vary among cardiac cells?

The size of the phase 1 notch varies among cardiac cells. It is prominent in myocytes in the epicardial and midmyocardial regions of the left ventricular wall and in ventricular Purkinje fibers. ...
3
votes
1answer
66 views

Fecundity per woman in early humans

The average fecundity per woman varies a lot from country to country. I call average fecundity per woman the average number of born children per woman. In Homo sapiens, what was the average fecundity ...
3
votes
2answers
161 views

What does “chlorophyll photosynthesis peak” mean in relation to photon wavelength?

When reading about how green / leafy plants work, I saw that they have chlorophyll A & B, which allow the plant to use the energy from light by capturing and transforming. When reading about ...
3
votes
1answer
375 views

Like other animals, why humans don't have species & breeds?

Like other animals, why don't humans have species & breeds ? Even my pet dog is one type of breed, but we (humans) lack breeds & species? What is the main reason?
3
votes
1answer
104 views

How does rate of evolution/innovation scale with population size?

I understand that there will be many other factors that affect rate of evolution/innovation. However, other things being equal, how will the rate of evolution vary between two populations of different ...
3
votes
1answer
49 views

Confusion regarding niches in evolution theory

This is the definition of a niche from Crash Course: An area of the environment that requires a special set of skills or traits to extract food and reproduce. Obviously, this version of the ...
3
votes
1answer
267 views

Why is Cysteine and Tyrosine used to calculate a sequence isoelectric point?

Why are the amino acids - cysteine and tyrosine used in isoelectric point calculations for a protein sequence, yet neither of them are positively charged molecules? and are not used in net charge ...
3
votes
1answer
76 views

What percentage of DNA do people share?

If you picked two people in the world at random, sequenced each of their entire genome, and compared their DNA, what would the expected percentage match be?
3
votes
3answers
155 views

Why can't you just take a vitamin? Why you need a healthy diet on top of that?

From what I understand, your body needs certain amounts of vitamins and minerals to maintain health. Why can't we just take enough pills to obtain these vitamins and minerals?
3
votes
1answer
98 views

Main mechanism of the evolution of sexual dimorphism

Sexual dimorphism is very common and (normally) requires the evolution of sex-specific genetic variation/regulation so the genetic correlation between the sexes can be <1. Is there consensus as to ...
3
votes
1answer
44 views

What class of histone deacetylase (HDAC) inhibitor is sodium valproate (VPA)?

VPA is a known HDAC inhibitor. But I cannot find what class it is. What class is it? And is there any method of finding an answer better than floundering with Google?
3
votes
0answers
38k views

Does CPH4 exists? [closed]

What is the purpose of CPH-4? Is it well represented in the movie Lucy?
3
votes
1answer
63 views

How common is it to be pregnant with periods?

As you may know, some women claim that they have their period while they are pregnant. In the arab world they call it "Deer pregnancy", since when the deer gets pregnant, it still gets its' monthly ...
3
votes
2answers
251 views

How to use Autodock just for (re)scoring

I have some protein-ligand complexed that I have been docking with some other software and just want to use Autodock to evaluate those complexes. So, basically I just want to use it as a scoring ...
3
votes
1answer
500 views

What types of light can't a plant photosynthesize in?

I have a plant on my desk, and it got me to wondering: Can my plant use the light from my monitors to photosynthesize? If so, what light (apart from green light, to a degree) can't plants use to ...
3
votes
2answers
301 views

How are two species with similar phenotypes identified as different?

How are two species with similar phenotypes identified as different? Have two different individuals that were thought to be different species ever been determined to be from the same species ( or ...
3
votes
2answers
2k views

Why does rabies cause hydrophobia?

What feature of rabies pathophysiology causes hydrophobia? Why is hydrophobia unique to this one particular type of viral infection?
3
votes
1answer
93 views

Book recommendation on selective breeding?

I am looking for a good book that gives a nice overview of the science and technics of selective breeding. I am particularly interested in the use of population genetics to support decision in this ...
3
votes
2answers
59 views

Is half-a-tablet of X a substitute for a tablet of X/2?

This may be anecdotal. At the pharmacy earlier, the prescription called for a drug with X mg of the target chemical. The pharmacy however only had stock of a higher potency of the same brand. E.g. ...
3
votes
1answer
250 views

Parasitism and mimicry

I was reading this article which states this: Classical Batesian mimicry, in which an undefended mimic evolves to look like a toxic model, is a parasitic relationship in which the mimic gains ...
3
votes
1answer
84 views

Is there a molecular basis to intelligence?

Is there any explanation, gene(s) or whatever detected, that are co-related or explicitly related via mechanical bio-molecular (or at any other level) models that explain the higher or lower ...
3
votes
1answer
1k views

What is the definition of “dry weight” and “dry cell weight”?

As I understand it, the dry weight of something is its weight minus the weight of its water content. Is this the definition? What about dry cell weight?
3
votes
1answer
131 views

Evolutionary Cell Structuring

I'm a total novice when it comes to biology, and I'm really just looking for an answer to a question that has been posed to me by people who deny evolution fervently. Evolution dictates that we've ...
3
votes
1answer
56 views

Euthyrodism and goitre

I read in Tortora and Derrickson that goitre is associated with euthyrodism. How is that possible?
3
votes
1answer
164 views

Number of genes required to sustain life

Are there estimates of the minimum number of genes required to sustain life? In what I mean by life here, I don't include viruses.
3
votes
1answer
479 views

Is there an optimal composition and length for protein linkers in FRET?

I'm designing a protein that I'd like to use in FRET reporting. General idea on the shape is: FRETprotein1--Linker--CleavageSite--Linker--FRETprotein2. I would like to know what AA are best for the ...
3
votes
1answer
161 views

Identification of this fly?

So I find these flies every year in my mulch, and I've never seen them anywhere else. The mulch becomes full of their larvae, which I feed to my toad and lizards. There are so many that you can hear ...
3
votes
1answer
149 views

Are similar smells usually based on similar chemicals?

Building off of this question: Why does freshly cut grass smell like a watermelon?, is it usually the case that things that we perceive as having similar smells are, in fact, the same or a similar ...
3
votes
1answer
126 views

Do insects respond to the detection of dead insects?

Are there insects that change their behavior upon detecting the nearby presence of other dead insects? If there are, can you provide an example?
3
votes
0answers
126 views

Good poly-A filtering rules or tools

I am aligning a large number of ESTs. It seems poly-A tails show in many different ways. In addition to occurring at the very end, they can be flanked by the cloning sequence one one end, or have ...
3
votes
1answer
707 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 ...
3
votes
1answer
144 views

Are any organisms known to use meiosis I to create non-identical offspring asexually?

So, there are numerous species of animals who use parthenogenesis, but to my knowledge the reproduction is clonal. That is, the offspring are identical to the mother. Are there any documented cases ...
3
votes
1answer
284 views

Macroevolution vs. microevolution

Where is the line usually drawn between macroevolution and microevolution? I thought that, although similar processes govern both, the line was at the species level, with macroevolution being changes ...
3
votes
1answer
160 views

What kind of caterpillar is this?

I've made a photo using the reversed 58 mm lens and my cropped DSLR: Could you please help? I really don't know where this came from. I found it in Russia.
3
votes
2answers
107 views

Do dolphins really sleep?

I have always wondered, if dolphins sleep with one eye opened, do they really sleep at all? According to this article dolphins indeed shut down their brains. I already googled it. No help from ...
3
votes
2answers
88 views

Is there a way to measure the amount of bytes that are possible to encode in a DNA molecule?

When I saw a DNA molecule for the first time, it kinda reminded me of a hard drive. It consists of slots and there are some possible combinations for each slot; in the hard drive these possible ...
3
votes
1answer
3k views

Speciation by polyploidy

Speciation can occur by polyploidy. My understanding of the process is as follows: 'polyploidy is when the number of chromosomes in an organism's cell doubles. This means that the organism has more ...
3
votes
1answer
1k views

Perception of artificial light - flickering

I noticed something strange a couple of years ago. I was walking down the street at night, when it struck me that the street lights were flickering. But, when I turned to take a direct look at the ...
3
votes
2answers
633 views

Why does Glutamine have the symbol Q?

Spent a half hour googling this and the best I could find was this: Now for some rhymes: Arginine = R. R we having fun yet? Asparagine = N The kNights of Ne say "Ne". Glutamine is a cute ...
3
votes
2answers
1k views

What is the evolutionary rationale for palm sweating?

Sweaty palms seems to be a reaction to stress, anxiety, etc. For our forest-inhabiting primate ancestors sweaty palms could cause unwanted side-effects such as slipping off tree branches under ...
3
votes
1answer
379 views

How are melatonin levels measured in humans?

I'm wondering how it is possible to measure diurnal variations of melatonin levels in humans. I keep reading that there should be a large difference in amplitude between melatonin levels measured at ...

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