All Questions

1
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1answer
166 views

Raphide toxicity in Pothos plant

Recently I found out that the common houseplant Pothos (Epipremnum aureum) is toxic to cats and dogs due to the presence of "insoluble raphides." I have a lot of these plants around my house and my ...
7
votes
1answer
210 views

What is this crow eating, and is it a common part of the corvid diet?

Here's a picture (by Rob Curtis) of a crow carrying and eating the corpse of what looks a bit like a small hawk or falcon: Other pictures clearly show the crow is eating the dead bird. This image ...
6
votes
1answer
689 views

Why does ostrich meat look and taste more like beef than chicken?

Some time ago I tasted ostrich meat, and what was amazing to me was that the meat very much resembled beef, much more than it resembled chicken, turkey or duck meat. And even more than lamb and pork ...
2
votes
0answers
51 views

What's the Efficacy of Ampakines in the Treatment for ADHD?

What's the Efficacy of Ampakines in the Treatment for ADHD? Ampakines are a class of drugs that serve as potentiators of the AMPA glutamate receptor. By so doing they serve as nootropic, anxiolytics ...
1
vote
1answer
60 views

What is a zygote?

During fertilization, the nuclear membrane of the pro-nucleus of the ovum and sperm degenerate. Is the cell is stage called a zygote? After the dissolution, mitosis occurs and two cells are formed.Or ...
5
votes
1answer
194 views

What evolutionary pressures pushed Galápagos tortoises to mature so slowly and live so long?

I read that they take up to 40 years (in the wild) to reach the age of reproduction and are thought to live over 100 years, with one in captivity reaching over 170 years. Can someone explain in ...
3
votes
2answers
69 views

How common is bacterial mediated transformation? In plants? In animal cells?

The most common method to transform plants is by soaking plant tissue in cultures of agrobacteria (this is not their current classification) which transfer DNA into the plants. Is lateral gene ...
1
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2answers
65 views

Collective term for both exons and introns

Is there a term I can use to refer collectively to both exons and introns? By collectively, I don't mean ligated as with an unprocessed transcription product. I'm just writing about exons and introns ...
5
votes
1answer
782 views

Why don't antibiotics affect mitochondria?

Given that mitochondria are evolutionarily closely related to bacteria, and antibiotics kill bacteria, why don't antibiotics also kill mitochondria?
6
votes
2answers
144 views

Would muscle fatigue still occur if aerobic conditions for a working muscle is maintained?

Put another way if the muscle is given everything it needs to contract and do work will it ever get tired or have a reduction in energy efficiency? As far as I understand muscles depend upon a ...
3
votes
2answers
328 views

Why do plants' leaves become enlarged in low light areas?

Why do almost all plants in shade have a smaller stem structure and larger leaf than that same species grown in a well lit, sunny area?
1
vote
2answers
61 views

The role of antibodies interacting with cancer

I'm learning about antibodies. As I understand it, antibodies detect stranger cells/bacterial/viruses by the molecules present in their membranes. In cancer cells, the cancer cell have produce some ...
1
vote
1answer
132 views

Is it really detrimental to humans as a species to reproduce with one's own first cousin?

Tired of hearing of these urban legends and popular opinions, I ask this question here to see if there really is scientific merit to this belief. My questions is, is it really "harmful" for a person ...
2
votes
3answers
109 views

Is it possible to make humans extinct artificially?

Verging on the realm of science fiction, my question is that is there any theoretically possible way, biologically/chemically, with which the entire human race can be killed without affecting the rest ...
3
votes
3answers
123 views

Are there any methods to quantify H2O2 (hydrogen peroxide) which don't rely on horseradish peroxidase?

I can't use HRP since my substrates interfere with it and I need a real-time method because I want to measure kinetic parameters of some oxidases.
1
vote
1answer
109 views

Is chlorophyll living or non living?

Is chlorophyll living or non living, and after boiling the water out of a chlorophyll extract would it still live, as in would it still maintain its properties after re-adding liquid to the dried ...
1
vote
1answer
67 views

Resource plant anatomy/lifecycle vocabulary

I've been curious about a lot of vocabulary words in the world of botany. I've had quite a bit of trouble finding somewhere online to help me out, but I'm having some trouble finding a resource like ...
1
vote
2answers
277 views

Does osmosis occur when we have two different substances?

Assume that we have a semi-permeable membrane with water on both sides. First, straightforward, case: On the right side, we have a concentration of the substance A, and on the left side, we have pure ...
0
votes
1answer
137 views

Why not produce protein based on condensation reaction?

I'm fairly new learning about protein. As I know protein can be synthesis by condensation reaction. And the current method to produce protein is purify them from an organism. So why not produce ...
1
vote
1answer
119 views

Origin of human intelligence and thought

I've been debating this topic with a friend of mine and we can't get to a common answer. She argues that we don't descend from any Chimpanzee or Orangutan because, if we did, they would also have the ...
2
votes
2answers
576 views

What is a cortical circuit?

I have read about cortical circuits in the context of connectomics (e.g. any example here) and computational neuroscience (e.g. any example here), but a simple Google/Wikipedia does search not show an ...
2
votes
1answer
94 views

Steroid Hormone Signalling

Can the lipid-soluble hormones (like steroid hormones) go inside every cell, as their particular receptors are located in the cytoplasm or nucleus of the target cells? Is there anything special on the ...
2
votes
1answer
450 views

Water potential in plants?

The concept of water potential in plants tries (and succeeds) to explain various movement and transports in plants. I have learnt that it can be though of being composed of various components like the ...
2
votes
1answer
71 views

Are genes associated with obesity selected for?

I've read that there are several SNPs associated with increased risk of clinical or morbid obesity. I was wondering if there is any evidence that these are under positive selection. Would you expect ...
1
vote
3answers
82 views

Would it be possible/plausible for a type of spider to fly by weaving web between it's legs to create bat-like wings?

I've been thinking about this lately. Would it be possible for a type of spider to gain the ability to fly freely by weaving its web between it's legs and creating wings much like those of a bat? Is ...
3
votes
1answer
966 views

What biological constraints are there on how large a spider can grow?

Spiders fascinate me, but what intrigues me the most is just how big some spiders can get, which leads me to my question. What biological constraints (if any) would limit how large a spider could ...
2
votes
3answers
1k views

How did this spider evolve to mimic exactly a human face and arms?

So I came across something terribly amazing today, that is, a video showing this species of peacock-spider, that literally, transforms into a human face waving his arms about. What could have ...
2
votes
0answers
80 views

Can Squirrels Eat Every Mushroom?

Squirrels have the ability to eat toxic mushrooms as described below. Are there any mushrooms that they can't eat without dying? According to Dr. John Rippon, an IMA member and world expert on ...
1
vote
1answer
99 views

Which kind of tick is this and what is that thing around its back?

I was recently bitten by a tick. After having removed it from my body, I put it in a glass. By now, it has stopped moving, so I put it under a microscope and looked at it. I was surprised about being ...
1
vote
1answer
88 views

How potent is the venom from the Australian platypus?

The Australian platypus, is a marsupial with a unique feature - in that the males of the species have venom sacs around their hind-claws. My understanding is that this venom is not lethal to humans, ...
1
vote
2answers
150 views

Why are animal births not taken as seriously as human births?

When humans give birth, more than often medical assistance is needed. Others gather around and frantically look for any way to help. But when an animal gives birth, it is usually seen as a moment ...
3
votes
1answer
109 views

In theory, would it be possible to create an injection of Vitamins, Minerals, sugars etc so that eating was no longer necessary?

I am wondering, out of pure curiosity, whether with current medical & biological science, (or indeed with accepted probable future developments in those areas), in theory, would it be possible to ...
1
vote
2answers
74 views

Why might food spoil faster in Ireland than the US?

An American is staying in my house for the summer and claims that food (specifically, bread and milk) spoils a lot faster here than at home in California. Is there a significant difference in chemical ...
5
votes
1answer
312 views

What causes humans to be sleepy?

Is there a hormone or group of hormones that regulates when we feel sleepy late at night, or in the morning? Or is sleepiness caused by some other non-hormonal mechanism? (e.g. pure psychological, ...
1
vote
1answer
50 views

Systematic difference of diversity between sister taxa?

When looking broadly at the tree of life, my feeling is that, after a divergence there is almost systematically one taxon that speciates way more than the other. (There will have some approximations ...
3
votes
1answer
50 views

Self pairing in DNA

I know that ssRNA molecule can fold over itself (e.g. in t-RNA). Can DNA do the same? Is there any example of this in nature? Why is this phenomenon more common in RNA than in DNA?
1
vote
1answer
80 views

Is Nerve Growth Factor (NGF) commercially available?

I'm curious if NGF, or Neurotrophins in general is available commercially. Can I order it online? If not, what are the medical/biological reasons. Does it breakdown quickly after synthesis/capture? Is ...
2
votes
1answer
105 views

What in the world is this critter?

We spotted this thing crawling around a (thankfully empty) bowl in our apartment in Barcelona, Spain. I have never seen anything like it. It appears to be some kind of caterpillar-like insect, but it ...
0
votes
1answer
24 views

Stopping the effect of hormone

Many hormones released by endocrine organs travel down in the blood and bind to specific receptors on the target cells. What then breaks that binding of the molecule with the receptor ? ( thus ...
1
vote
1answer
58 views

DNA preparation for sequencing

In shotgun sequencing method or some related method that DNA is break up into random fragment. The fragment that have about 3kb in size is inserted into plasmid by enzyme ligase and then plasmid ...
0
votes
0answers
58 views

Freezing collagen aliquots

I'd like to regularly coat some dishes with collagen (Rat Tail, Sigma C7661) for use with PC12 cells. As I only need a small amount each time, I would like to know about any experience in freezing ...
2
votes
2answers
367 views

Do the four cells produced by meiosis each divide into four cells again?

In the beginning of meiosis, there is one cell. During meiosis, 1 cell divides into 4 cells. Does each of these 4 cells divide each into 4 more cells?
6
votes
3answers
752 views

What percentage of protein isoforms have different functions?

I am looking for studies on how many protein isoforms have different functions, preferably in human. We know that a great many, if not most, of human genes are alternatively spliced and that many ...
9
votes
2answers
130 views

What role does a protein's size have on protein-protein interactions?

Protein-protein interactions are when two or more proteins bind together, possibly for some important biological function. Recently, I'm starting to look more into proteins, and in particular, ...
2
votes
1answer
54 views

How do cells figure out the big-picture shape?

I'm wondering what makes cells to divide (and stop) in such a way that they make our hands the shape that our hands are...
2
votes
0answers
41 views

Which mass spectrometry database search algorithms include the fragment mass accuracy in the calculation of protein scores?

E.g. in a MASCOT search, the accuracy of the fragment ions in a ms/ms spectrum does not have any influence on the scores of identified proteins (unless the fragment ions are out of the set ms/ms ...
-1
votes
3answers
74 views

Could sex alone drive complexity?

Imagine that complexity is measured by a positive number $f_n$. If one has no prior knowledge about the positive number $f_n$ then from Bayesian theory one can assign $\log f_n$ an "improper" uniform ...
5
votes
1answer
157 views

What is this insect I found in Russia?

I found this in Russia. It is approximately 2cm long.
4
votes
1answer
47 views

Is there a type of amnesia that seperately affects long-term memory?

Is there a medical condition that affects the long term memory, but leaving the short-term and working memories totally or fairly intact?
16
votes
1answer
283 views

Do marine deep sea life forms exhibit circadian rhythms? If so, what entrains them?

I've been reading a lot about circadian rhythms, when suddenly this question popped into my head: do circadian rhythms exist for deep sea organisms (3000 ft / 1000 meters+)? For land mammals, the ...

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