5
votes
1answer
403 views

What makes an animal/species suitable for domestication/training?

Humans have domesticated all manner of creatures during the course of their civilization - dogs, horses, several types of cattle, varieties of birds, and perhaps others too. A prerequisite for an ...
4
votes
2answers
315 views

Were there lifeforms before LUCA?

This question got me thinking about something. LUCA is the last universal common ancestor of all current living organisms, which is a very different definition from the first-ever living organism. Is ...
3
votes
1answer
361 views

What is the known maximum ranging distance of a bat's sonar?

Bats are known to navigate by using echo-location. How far away can a bat detect an object by its sonar?
6
votes
3answers
316 views

Are there genes in humans from the common ancestor of all organisms?

How long ago can human genes be traced? Are there any genes that go back unchanged to the beginning of life on Earth? And if so, how many?
1
vote
1answer
911 views

Why do drugs which are hormones have long half-life?

Hormones normally have short half-life. How is it possible that they have long-life in drugs?
7
votes
1answer
912 views

What determines the colors and patterns of a clam shell?

Earlier this week I was looking at some bivalve shells that had ornate patterns which ranged in color from a light orange-pink to a deep orange-red. Here is an image I found online that seems to be of ...
19
votes
3answers
45k views

What is the difference between orthologs, paralogs and homologs?

These three terms are often misused in the literature. Many researchers seem to treat them as synonyms. So, what is the definition of each of these terms and how do they differ from one another?
2
votes
1answer
972 views

Why does high-voltage mostly shock a person, and even small current kill?

This may be the wrong forum to ask. For instance several people are known to have survived a direct lightning strike; albeit the number of fatalities are probably far larger. Anyway, I found myself ...
2
votes
1answer
91 views

Reattaching body parts

Is there any living organism that has the ability to remove and reattach body parts at will? I'm not talking about regeneration (like in starfish). Say I'm chasing prey, and I decide that my tail ...
8
votes
1answer
986 views

Are there any solitary species of ant or termite?

The social insects consist of the ants, the bees, and the termites, which live in colonies rather than living solitary. But I've heard that there are some species of bee which are solitary and don't ...
4
votes
1answer
130 views

Are there any websites offering graphs for the light absorption of different enzymes?

I have found graphs for the light absorption of water, haemoglobin, lipids, melanin, etc., but I am having a hard time finding graphs about enzymes. Are there any websites or other reference sources ...
4
votes
1answer
341 views

Genetic engineering for insulin production

In order to put human DNA inside a bacteria in order to have it create Insulin, from what type of cell would you need to take the gene for insulin? I thought it should be from any somatic cell, since ...
1
vote
1answer
235 views

Why must the alcohol decolorizer be used for 30 seconds or less for Gram staining?

I had today a class in microbiology and my teacher said that the Decolorizer component is the critical one and cannot be more than 30 seconds. The decolorizer has alcohol in high concentration, my ...
4
votes
1answer
1k views

Conversion rate of topical Retinol to Retinoic Acid (Tretinoin)?

I'm wondering if someone out there has more information than me. Retinoids have well known metabolic pathways in vivo, and it's usually something like: ...
8
votes
2answers
82 views

Should we be looking for extra-terrestrial life on comets?

I have just read What elements are a possible basis for life? and I find myself wondering whether instead of seeking advanced life-forms at remote locales a La SETI, and perhaps fundamentally ...
5
votes
2answers
446 views

What were the mammal ancestors like 65 million years ago?

What we know about our mammal ancestors that were alive (and survived) at the extinction event 65 million years ago?
3
votes
1answer
215 views

Amount of neurons in the heart

Finding numbers for the amount of neurons in the brain is quite easy. Finding them for other human organs is harder. How many neurons are there in the human heart?
5
votes
3answers
207 views

Can children restore brain cells?

By "children" I mean young people at the age of 10 or lower. I know that the adult brain cannot restore brain cells, but what about children? I mean, the brain must develop from a few cells to a 90 ...
2
votes
1answer
452 views

Can the RNA in the HIV virus make viral enzymes without entering the nucleus?

If the provirus was not formed yet, can the virus make viral enzymes? (I know that it already has some, but supposing it doesn't)
5
votes
2answers
63 views

Flow cytometry issues

I'm having problems with data analysis here. I have flow cytometry data being collected on a Fortessa, and when I import them into FlowJo 8.7, all of my fluorescence values are systematically 10X ...
1
vote
1answer
253 views

What does “cellular” mean in this context?

I came across a confusing word when I was reading a Scientific American story, “Controversial Spewed Iron Experiment Succeeds as Carbon Sink” (by David Biello). It goes like this: “One key to the ...
2
votes
2answers
401 views

What does “delineate” mean in this context?

I was reading a Scientific American story, “Controversial Spewed Iron Experiment Succeeds as Carbon Sink” (by David Biello), when I came across this sentence: “The problem for scientists is that ...
14
votes
1answer
215 views

Has the human 7-day week had any impact on the evolution of species?

Most (if not all) industrialized countries follow a 7-day work week now, such that we are bound to follow a certain weekly trend in matters such as pollution generation, where to go (e.g. stay in town ...
2
votes
1answer
578 views

Has the age at which menopause occurs changed throughout history?

I was reading recently that the age of menarche has decreased in the last 150 years, and was wondering if the age of menopause in humans has also changed recently? Would there be selective pressure ...
8
votes
1answer
4k views

Why can't humans drink sea water?

Why can't humans drink sea water? It would seem to be a huge evolutionary advantage for an animal to be able to drink sea water rather than have to rely on fresh water, and it's provably not ...
7
votes
1answer
87 views

Do antisense transcripts have different names than their sense strand transcripts?

I want to find which genes in the human genome can potentially be complementary to a transcript that could act as antisense transcript inhibtion? Are cis-NATs (naturally occuring anti-sense ...
5
votes
1answer
2k views

Does the light color spectrum and frequency matter for photosynthesis?

Do plants grow differently when given sun light, wolfram lamp, fluorescent light, LED light, infrared, ultraviolet, x-ray, unfocused laser and stroboscope?
2
votes
0answers
21 views

How to seek information on the duration of biological entrainment processes in mammals? [closed]

This is a question that is a little bit hard to define for me. I'm interested in learning more about times of "attractor/entrainment" processes that may take place in the body/brain of mammals, and ...
8
votes
2answers
1k views

Scoring sequence against position weight matrix

I have a weight matrix of length 20 x 15 (amino acids x sequence positions). Each element of my weight matrix is a relative probability If I have a sequence say "AAPGTGASMHSGLLW" how would I score it ...
3
votes
1answer
379 views

Can Naegleria fowleri enter through the eyes ( example rinsing/splashing eyes with water)

I understand that it primarily enters the body through the nose by by "feeding on the olfactory neurons in the nose" as answered here in a different question. Would the nerve cells in the eyes present ...
5
votes
1answer
105 views

Does the Heart Require Gold?

I distinctly remember an episode of NOVA from the early 1980’s that concerned itself with gold. One of the points that was made was that there are trace amounts of gold in the human body, ...
4
votes
2answers
2k views

Why does alcohol cause the hemolysis of RBC in a large proportion?

I had today an experiment that we put 95% alcohol to the blood which made it completely transparent so hemolysis must have occurred. I started to think about the reasons. I think that this is because ...
8
votes
1answer
785 views

Does drinking coffee have negative effects?

From what I collected, coffee is a magical potion that lets you feel energetic, and essentially not-sleepy. But are there any tradeoffs? I mean, if it was so beneficial, wouldn't the human body ...
3
votes
1answer
29 views

Mutation in axillary buds of trees overcoming self-incompatability?

I seem to recall from either reading or lecture that there have been instances of trees that are self-incompatible accumulating enough mutations in an axillary bud that the resulting branch was able ...
5
votes
2answers
1k views

Does cooking or ripening reduce the concentration of solanine in nightshade?

I recall a story from one of my Botany professors where he encountered a woman picking Solanum dulcamara (nightshade) berries. When he asked her what she was doing with them, she responded that her ...
3
votes
1answer
890 views

“Acellular” designation for organisms

Why do some biologists refer to single-celled organisms such as Amoeba and Paramecium as acellular (i.e., without cells) rather than unicellular (i.e., one cell)?
5
votes
1answer
914 views

What gives things their colour?

My 6 year old daughter asked me 2 biology-related questions yesterday and I tried my best to answer them with the aid of YouTube videos. One of the questions (I may post the other one too) was ...
2
votes
1answer
107 views

At what substrate concentration will an enzyme work at 40% of its maximum rate if its Km = 0.095M?

The question involves the Michaelis-Menten kinetics equation. Here is what I did: I took the Michaelis-Menten equation, replaced v with 0.4Vmax, canceled the Vmaxes (one on each side), and solved ...
6
votes
1answer
287 views

Do all mushrooms have the same multicellular ancestor?

Do all mushrooms have the same multicellular ancestor? Did that ancestor feature common mushroom elements such as cap, stem, sporofore, vulva, bulb, etc.
8
votes
2answers
31k views

Which shades/hues of color are easiest to distinguish for humans?

I'm trying to represent data graphically and am using a variation of hue/lightness to distinguish one data point from the next. I would like to use a color that would allow me to convey most ...
4
votes
2answers
8k views

DNA as an acid? [duplicate]

Possible Duplicate: Does DNA react in all of the ways most other acids do? Even if DNA is made up of nucleotide bases, it is said to be an acid. Why is this?
5
votes
2answers
3k views

Why does milk contained in cartons of milk expand?

In the morning, I went to the fridge to drink some chocolate milk. At night, when I took out the same carton of milk, the packaging seems expanded, like some kind of air is inside. Explain please !
5
votes
2answers
613 views

Sparking during electroporation of plasmid DNA into bacterial cells

During electroporation of bacterial cells (I work with Mycobacterium tuberculosis, but I think this applies to E. coli as well), sometimes I get sparking. I've read this is due to salts present, ...
4
votes
1answer
350 views

Ammonium sulphate precipitation assay pH dependence

In general does the pH effect the precipitation, e.g. would a pH of 6 cause less precipitation than pH 7.5. Or are they unrelated?
6
votes
2answers
200 views

Do diurnal birds of prey recognize each other by their appearance?

Just what the title states. I recognize people around me by their facial appearance to begin with, then by their little idiosyncracies; this applies perhaps to most other humans too. We rely pretty ...
5
votes
1answer
520 views

If proteins have an overall charge, how do membrane proteins traverse through the hydrophobic region of the plasma membrane?

These two concepts seem almost contradictory, proteins have a net negative charge due to the amino acids in them each having a small negative charge, yet membrane proteins are able to exist traversing ...
3
votes
1answer
120 views

Where are -HCl supplements absorbed in the human digestive system?

I see that quite a lot of drugs and dietary supplements sold in the USA have -HCl(hydrochloride) added to their name. For example pyridoxine hydrochloride for Vitamin B6. I'm interested in knowing ...
2
votes
1answer
58 views

What type of biome is this?

There is a region that gets about 812mm of precipitation and is mildly hot all year long. I believe this region is a tropical savanna, but I'm not 100% sure. Is this correct?
6
votes
2answers
8k views

Do other male mammals except for humans have nipples?

When I grew rabbits, I had a pair, one male and one female. And while the female's nipples were quite prominent, especially after giving birth, I don't remember the male having any nipples at all. Do ...
6
votes
1answer
343 views

Why do the feet of the Gecko Lizard not stick to Teflon surfaces?

I have noticed that lizards feet can stick to walls but not to Teflon surfaces? Why is that?

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