23
votes
Accepted
How did the largest/longest dinosaurs hold their head and necks up?
There are lots of papers on this. A good summary article is Why sauropods had long necks; and why giraffes have short necks, by Taylor and Wedel. They list a number of anatomical features that ...
- 14.2k
8
votes
Accepted
Why does resting potential not become continually more negative?
The resting membrane potential is due to internal/external differences in ion concentrations and very importantly differences in permeability to those ions.
The fact that the sodium/potassium pump ...
- 43k
8
votes
How do disulphide bonds in hair cause curling?
Nice question. I must say it took me many hours to get satisfactory answer.
Hairs are made of keratin molecules, which contain cysteine. Cysteine has thiol (-SH) group, by which it can form disulfide (...
- 14.1k
6
votes
Accepted
Any simulations of four-winged dinosaur flight? (microraptors)
Note nowhere in the article does it mention the rear wings flapping. The rear wings do not provide lift, they are acting as control surfaces to improve stability and maneuverability. (think of the ...
- 14.3k
5
votes
Any simulations of four-winged dinosaur flight? (microraptors)
There is a good attempt at a simulation of 4 winged flight of Microraptor on BBC's Planet Dinosaur.
There's another Planet Dinosaur video about their venomous teeth and hunting tactics.
And a ...
- 10.3k
5
votes
Are there any predators without camouflage?
Poison dart frogs have aposematic colouration, making them the exact opposite of camoflaged.
They are also predators, since they feed on ants, termites and beetles.
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4
votes
Highest bite force of a wolf?
The range from mean to maximum of wolve's bite force is huge.
Is it really? According to this Wikipedia page, (Scully, C. (2003). Oxford Handbook of Applied Dental Sciences. p. 151) claims that human ...
- 1,515
4
votes
Can geckos climb a wet surface?
Short answer
Yes they can, but with less efficiency.
Background
Efficiency of sticking to a glass surface decreases about 20-fold when the gecko's feet are wet (Stark et al., 2012). On dry glass, ...
- 52.3k
3
votes
Why do we have the tibia and fibula (a 2nd bone) in the lower leg?
It does function in the rotation and stabilization of the foot, but that is not why we have it, even species in which it serves no function still have it. A bone does not necessarily have to have a ...
- 14.3k
3
votes
Accepted
What is the acceleration profile of the greyhound?
I'm going to try to break this up a bit to address your sub-questions. Most of it is summarized from Williams et al 2008--and almost all of the work I'm referencing comes from the Royal Veterinary ...
- 587
3
votes
Accepted
Does the human abdominal cavity use pressure to maintain posture?
I found this review which can help to clarify this notion of intra-abdominal pressure : Intensive Care Med. 2009 Jun;35(6):969-76.
What is normal intra-abdominal pressure and how is it affected by ...
- 76
3
votes
Are there any predators without camouflage?
What is a predator?
As discussed in the comments by @MarchHo and @AMR, there is discrepancy between the definition of predation in the biology literature and in the every day use.
Population ...
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2
votes
How do proteins perform their function
This question is waaaay too broad, but I'll give some short and simplified answers to the hypothetical you asked at the end. First, let's reformulate your example a little bit:
How does the ribosome ...
- 3,781
2
votes
Accepted
How fast is the patellar reflex?
Mamizuka et al. (2007) calculated acceleration data of the patellar reflex.
Their study measured the reflex generated in response to the tapping force applied to the patellar tendon with a ...
- 29.6k
2
votes
Accepted
Why metacarpus is considered hand proper?
Proper in this instance means the main body of the hand, the part that has no other identifier. the fingers and wrist have other terms to identify them, the hand proper does not. If I say the the hand ...
- 14.3k
2
votes
Any simulations of four-winged dinosaur flight? (microraptors)
Several models have been proposed, challenged, and revised over the past two decades:
Origin of Flight: Could ‘four-winged’ dinosaurs fly?, Nature (2005)
A previously published reconstruction ...
- 1,562
2
votes
Accepted
In human anatomy / biomechanics, what is the motion called when the arm swings sideways so the elbow moves in an arc of 90 degrees?
It’s humeral retroversion at a 90 degrees abduction angle with extended elbow and slightly internally rotated shoulder.
- 89
2
votes
Accepted
Biomechanics of cells (stress, strain, tension..)
Strain and stress are two essential quantities in elasticity theory, corresponding to the deformation and the forces appearing in response to this deformation. Tension or tensile stress is a ...
- 3,822
2
votes
Accepted
What’s the term used to define a terrestrial being that moves by using six limbs?
Hexapedal. From wiki > Hexapedal
Having six legs
Note that Hexapoda is a taxonomic group including insects and the smaller groups that are Collembola, Protura, and Diplura.
- 67.9k
1
vote
In human anatomy / biomechanics, what is the motion called when the arm swings sideways so the elbow moves in an arc of 90 degrees?
Shoulder Horizontal Abduction/Adduction.
https://www.youtube.com/watch?v=R3xJDsJ_Nw4&ab_channel=InteractiveBiology
"the motion of bringing the arm across the chest is called shoulder or ...
- 735
1
vote
Accepted
Is there any small animal that can jump over a meter high/long?
no animal smaller than 5 cm can jump higher than 1 meter. grasshoppers and locusts have wings which supposedly disqualifies them. https://www.guinnessworldrecords.com/world-records/highest-jump-by-an-...
- 925
1
vote
Accepted
How lungs can inhale and exhale?
(Note: Since the question language isnt clear; it just seems to me the
1. The purple-blue "Wall" (technically the plurae; containing plural space not shown) is being refered as the bag.
2. The ...
- 2,669
1
vote
Highest bite force of a wolf?
In this article (Bite forces and evolutionary adaptation to feeding ecology in Carnivores) they say, that bite forces of wolf (Canis lupus) is 774 N. Literature (Maximum estimated bite force, skull ...
- 88
1
vote
Accepted
Reference for the bite force for Nile Crocodile
Here is a video by Brady Barr (video in YouTube) measuring 5000 lbf for an adult Nile Crocodile. This is equivalent to 22.24 kN (more than 2.2 tonnes of force). This result is also refered here (Getty ...
- 1,086
1
vote
What is the purpose of the viscous gel in the Pacinian corpuscle?
Short answer
The adaptation process in Pacianian corpuscles (PCs) is mediated via the outer capsule. This capsule is an onion-like structure that quickly molds itself to pressure stimuli, thereby ...
- 52.3k
1
vote
Are there biological ratchet cycles that are small in number?
First I would in return ask why the actin-myosin coupling should not qualify - the many repetitions of this contractile unit never contract at exactly the same time, and their combined contractile ...
- 7,630
1
vote
Accepted
How does the brain alter/inhibit muscle reflexes?
how exactly the brain interfaces/controls/disables such automatic muscle reflexes when it needs to?
A: At multiple places within a hierarchical system:
In a simplified way, the Motor cortex is the ...
- 220
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