7
votes
1answer
721 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
24 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
676 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
757 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
99 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
211 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.
9
votes
2answers
26k 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
5k 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
2k 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
473 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
301 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
173 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
339 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 ...
2
votes
1answer
110 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
55 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
5k 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
239 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?
4
votes
2answers
773 views

Bone conduction . Different from the normal hearing phenomena in humans?

Bone conduction, is it something different from the normal phenomena of listening through the ears. I checked on some literature . Is it so that Bone conduction has very less to do with the ears and ...
5
votes
1answer
137 views

What protocol does the nervous system use?

I just read How does an inhibitory synapse communicate to the cell body of a neuron? and found myself asking this question ... hopefully I'm not asking the same thing Any body possessed of a nervous ...
9
votes
2answers
1k views

Why can't a human regenerate limbs like some other species?

When a person's arm is amputated, the arm will no longer be able to grow back. However, in salamanders, the arm actually grows back. In comparison to a human, what is really happening to the cells ...
6
votes
1answer
97 views

What is the oldest example of DNA identified?

What is the oldest sample of genetic material (presumably DNA) identified? What are the prospects of pushing back much further into the geologic record?
4
votes
0answers
110 views

Organize sequence database [closed]

I recently took up the task of organizing the sequencing database for a research project. I am still quite unsure of which database type I should use for this. Some advices/recommendations would be ...
2
votes
1answer
851 views

Is it possible to still grow taller after grow plates have been closed?

In addition, when do we know we stop growing taller? Or we keep growing taller? To the first question: Recently, I went to a doctor to have a check up, he said that my growth plates are closed and ...
2
votes
1answer
342 views

Can visual acuity be improved?

Is it possible to completely cure myopia using natural methods (i.e. not with Lasik etc.)?. I have seen websites claiming that exercising the eyes will help improve eyesight. Is this true?
7
votes
1answer
150 views

Do goldfish really have a 5 second memory span?

I heard that when people place goldfish in another tank, they just forget where they where previously? True or False ?
2
votes
1answer
446 views

Why does non-continuous sleep makes you feel tired?

Let's say, hypothetically, that you fell asleep at 10PM, and you were woken up by a noise at 1AM. If you went back to sleep immediately and woke up at 6AM, you will feel tired even though you had ...
1
vote
1answer
622 views

Difference between Condensin and Cohesin proteins?

The chromosomal DNA is stacked with help of cohesin and condensin protein in which particular manner? Can cohesin be said to form kinetochore? How would they vary exactly? The terms are so narrowly ...
6
votes
1answer
132 views

Number of spindle fibres during Metaphase?

During metaphase, the chromosomes are arranged on the equatorial plate and are attached to spindle fibres. After S phase, can the cell be said to attain the configuration of 4n? Also, during ...
1
vote
1answer
31 views

Can a plant be induced to accelerate transpiration?

Just what the title states. I wonder whether it is possible to fire a chemical switch - sort-of like injecting adrenaline in a human, to accelerate a particular process in a plant. For example, ...
18
votes
5answers
4k views

Why do the two hemispheres of the brain control the opposite sides of the body?

Why does the left hemisphere control the right and the right hemisphere control the left? I googled it but didn't find a good answer regarding this. Could someone explain? Does this adaptation help ...
4
votes
2answers
269 views

Why is the floral biodiversity of grazed grassland higher than that of mown grassland?

I have collected some data to compare the biodiversity of a field in which the plagioclimax is maintained by machine mowing with a field in which the plagioclimax is maintained by sheep grazing. What ...
3
votes
0answers
73 views

Experimental techniques to measure protein-protein and protein-ligand structure and dynamics

We would like to compare our simulation results with experimentation. When one wants to follow experimentally the dynamics (and possibly structure) of protein-protein or protein-ligand docking ...
5
votes
2answers
607 views

Why does squinting allow you to see objects more clearly?

How does squinting alllow one to see clearer pictures? What are the harmful effects?
0
votes
1answer
252 views

Why is offspring of identical twins not identical?

When identical twins marry identical twins, the children of the couples will be full genetic siblings but why are they not genetically identical?
7
votes
1answer
851 views

What really happens when a body is tired?

This may be anecdotal; please feel free to vote to close. After staying awake for an extended duration, I usually find myself having to take extra effort to focus my eyes on an object. Similarly ...
9
votes
1answer
328 views

Does DNA react in all of the ways most other acids do?

As I understand it from my basic chemistry, there are some fundamental reactions that exist between any acid and other substances for example acid-base reactions that form a salt, and the existence of ...
2
votes
1answer
148 views

Can epigenetic changes affect reproductive success?

This is prompted by niallhaslam's answer to this question [Since Darwinian times, has there been any striking/notable effects of evolution on humans?]. A comment by Alan Boyd asks whether epigenetic ...
2
votes
1answer
54 views

Biology view on trait variability

In reading the annotated Origin... I have come to the following note by Costa on p. 168: Again, modern biologists would disagree with Darwin's idea that especially well-developed traits vary to a ...
2
votes
1answer
46 views

What is the title of Darwin's paper on cellular structure?

I read somewhere that Darwin wrote a paper that dealt with cellular structure, but I've been unable to find the title or contents of the paper because Darwin wrote such a volume of material. What is ...
5
votes
2answers
85 views

Average number of gene products in (a) eukaryote(s)

Due to alternative RNA splicing, it isn't uncommon to ultimately find multiple gene products expressed from one gene in eukaryotes. I'm looking for a reference value for the average number of final ...
2
votes
1answer
79 views

Tubing connector identification request

this may not be on topic but I'm hoping someone here can tell me the name/manufacturer of the connectors used with the thin teflon tubing in this picture:
3
votes
0answers
49 views

Patch-Clamping Neurons Resources

Are there any lectures available on Patch-Clamping? Were can I find a mathematical model of Patch-Clamp? (that can be easily implemented in matlab). I have found some step-by-step protocols on ...
4
votes
3answers
148 views

Since Darwinian times, has there been any striking/notable effects of evolution on humans?

I understand that evolution is constant process that acts on a population in successive generations. Thus, it is obvious that evolution is happening. However, I'm curious as to the stricking examples ...
2
votes
1answer
46 views

Similarities Between Cells?

Which of the following are usually identical between a lung cell and a brain cell, from the same person, assuming that they are normal (non-cancerous) cells? Circle your choice(s). ...
3
votes
2answers
3k views

Is there an evolutionary reason for the 5 electron transport complexes in plants and animals?

The electron transport chains of both the light reactions of photosynthesis (in plants) and oxidative phosphorylation (in animals) both contain 5 complexes including ATP synthase, as shown below. ...
2
votes
2answers
300 views

Translate DNA to Protein

Assuming the sequence shown is read left to right, what is the sequence of the protein produced? sequence: 5’-ATGTACTTCCATCTGGAATAG-3’ MY ATTEMPT: I know RNA is synthesized 5 to 3. This is ...
2
votes
2answers
115 views

Is it more likely that the very first living organisms had a linear genome?

Is it right to assume that the first living organisms on earth had a linear genome? I base this on the fact that linear macromolecules are clearly much more common in nature that circular ones. To be ...
4
votes
1answer
36 views

Are there any strictly chloroplast/mitochondrion-residing ribozymes?

A simple question that had occurred to me. Considering the small doubt of transcribed genes in both organelles, I would doubt it, but are there any known ribozymes strictly found in either ...
2
votes
1answer
51 views

Preserved alpha complementation over evolutionary time?

Has the result of alpha-complementation ever happened via mutation through evolutionary time, and been preserved in modern day organisms? In other words, has a functional gene product ever been split ...

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