Most Popular
1500 questions
16
votes
3 answers
Does any organism use both photosynthesis and respiration?
Chlorophyll and hemoglobin are very similar molecules, as far as I understand. The important difference being one using an iron atom and the other a magnesium atom. Do any organisms use both to get energy from both oxygen and solar rays? If not, is…
LocalFluff
- 520
- 1
- 4
- 15
16
votes
1 answer
What limits the maximum spacing of Nodes of Ranvier and which organisms tend to have the widest gaps?
Assuming that a longer distance between gaps in the myelin sheath is beneficial for an organism due to the increased propagation speed, what is the limiting factor in determining the maximum spacing between nodes? I have previously encountered the…
Rory M
- 13,479
- 9
- 56
- 96
16
votes
2 answers
Are the inverse problems of Systems Biology impossible to solve?
I have heard Sydney Brenner give a talk [0] on how the entire program of Systems Biology is suspect because, according to him, a chap named Hadamard showed that inverse problems are impossible to solve, or something to that effect.
I find it…
Joebevo
- 849
- 6
- 16
16
votes
1 answer
What made this black cluster on a leaf?
I found this black slug-shaped thing on a leaf by my pond in western Sweden. It's about 15 mm long, positioned on a vertical leaf (I bent it to take the picture).
And I don't even know where to start looking. I was thinking it might be an egg…
picapica
- 2,039
- 1
- 14
- 23
16
votes
1 answer
Are the bacteria in the stomachs of unborn babies beneficial?
Babies are born with bacteria in their stomachs. I heard on The radio that when a child is given antibiotics for the first time unique bacteria in the stomach are destroyed and cannot be replaced. Is this true, and, if so, does this have negative…
Muze
- 1
- 2
- 10
- 32
16
votes
5 answers
Why have parasites not evolved to be harmless?
I have yet to understand why so many viruses or bacteria haven't evolved to be harmless (specifically, I don't know of any harmless viruses). I think it would be greatly beneficial for a virus to control its population and use natural transfer…
chubakueno
- 301
- 2
- 7
16
votes
1 answer
How does paracetamol work?
Hinz et al. 2008 found that COX-2 may be inhibited by paracetamol, and this is attributed to it's analgesic and antipyretic properties. However, there are other more recent claims from Andersson et al., 2011 that a toxic intermediate metabolite,…
James
- 11,305
- 8
- 58
- 112
16
votes
1 answer
What effect has changing pH and salt concentration on protein complexes?
I'm struggling to find peer reviewed literature that explains the effect of changing the pH and the salt concentration on protein/protein complexes in solution. What effect does the pH and the salt concentration have and what is the physical basis…
harpalss
- 2,573
- 3
- 20
- 37
16
votes
4 answers
Do birds emit infra-red radiation?
I'm an electronics engineering student and I am going to use a sensor that detects infra-red emitted by birds that invade rice paddies.
Do birds emit infra-red radiation?
reeglysonforubuntu
- 173
- 1
- 4
16
votes
3 answers
Why don't our cells merge when their phospholipid membranes touch each other?
Membranes of our cells consist of lipid bilayer (with some other components mixed in). Why wouldn't those lipid bilayers glue to each other and make the cells merge? If you suppose that it's due to additional components in the membrane that prevent…
Boris Burkov
- 361
- 2
- 7
16
votes
3 answers
How are long time periods measured in biological systems?
Biological systems are pretty good at measuring fairly long times, for example, menstrual cycles (month), or puberty (years). Counting days or years seems to be implausible, and chemical concentration also seems implausible. What are the…
Memming
- 3,080
- 2
- 21
- 40
16
votes
1 answer
What have the L-systems (Lindenmayer systems) been actually used for in biology?
From Wikipedia:
An L-system or Lindenmayer system is a parallel rewriting system and a type of formal grammar.
L-systems were introduced and developed in 1968 by Aristid Lindenmayer, a Hungarian theoretical biologist and botanist at the University…
woh
- 161
- 2
16
votes
4 answers
Is there any documented evidence for suicide among vertebrates other than humans?
Is there any documented evidence for suicide among vertebrates other than humans? Lemmings not accepted !
Poshpaws
- 7,292
- 2
- 33
- 53
16
votes
2 answers
How can computer predictions of protein folding be verified computationally?
Currently, there is a lot of research focused on solving the folding patterns of proteins using computers (Folding@Home, https://fold.it/portal/, etc.).
The question that I have is: How do you know when you get it right? Is there some way of…
Stack Tracer
- 263
- 1
- 6
16
votes
4 answers
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?
EDIT:
@TomD is right, I was asking why we have…
Gabriel Fair
- 4,509
- 8
- 37
- 71