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12
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3 answers
Is there any virus that contains both DNA and RNA in its genome?
It is known that viruses contain DNA or RNA- either one and not both.
I came across a question: Which virus contains both DNA and RNA?
rishab bairagi
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Why do animals have more heavy nitrogen and carbon than plants?
There are two stable Isotopes of nitrogen N14 and N15. The ratio of
15N/14N tends to increase with trophic level, such that herbivores
have higher nitrogen isotope values than plants, and carnivores have
higher nitrogen isotope values than…
Marijn
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What biological functions does crying serve?
Tears suddenly start flowing out of our eyes when we find our long lost friend or when someone unexpectedly decides to break up with us. Do tears really save us from harm? Or are they just the reflex shown?
What biological purpose do tears serve for…
علی آفاق
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What is the definition of a mutation?
There are two alleles that determine the sensitivity of a person to Coumadin (a medicine for blood thinners used to treat a stroke etc). Sometimes you encounter the terminology that one has a mutation on both alleles (father's and mother's side).…
Marijn
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12
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3 answers
In a tumor, why hypoxic regions have access to glucose?
The Warburg effect is ubiquitous in cancer. It consists of the upregulation of glucose uptake, glycolysis, and subsequent lactate secretion, sometimes by over 200 times, in cancer cells as compared to normal cells. A common explanation for this…
a06e
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12
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1 answer
Why aren't plants' roots as diverse as leaves?
I have been doing some gardening recently and I suddenly realised that all plants have superficially identical non-woody roots of the same size from gigantic trees to small fruiting plants and vegetables. They are all white, no more than 1 mm…
CJ Dennis
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Why and how is DNA synthesis so much faster then RNA synthesis in bacteria?
DNA synthesis in E. coli is 20x faster than RNA synthesis at 1000nt/s vs 50nt/s. (Mirkin'05)
I find that perplexing since DNA polymerization has better proofreading than the RNA variety, which requires extra time as you need to backtrack, excise,…
SeanJ
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12
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Why is an HIV infection considered "incurable"?
My biology teacher told me that if one caught HIV, they cannot be cured because it was near to impossible to be completely virus-free. She said this was because HIV keeps on changing its glycoprotein coat.
Can someone please explain what she meant…
user18914
12
votes
2 answers
How does life change when you dig deeper?
I've just realized that I have no idea what life / biotopes / soil looks like when you dig deeper than a few meters.
I know that in the first meter of soil you can find all sorts of live animals (like moles and rabbits), insects (like ants, but many…
Martin Thoma
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Do spinal cord reflexes (such as the knee-jerk reflex) continue to function under general anaesthesia?
The knee-jerk reflex (patellar reflex) is an example of a stretch reflex (myotatic reflex). Stretch reflexes are monosynaptic reflexes happening in the spinal cord without involvement of the brain.
Does it mean that this reflex will continue to…
amoeba
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Did I just watch a spider die?
So I'm sitting in my office and all of a sudden a small spider is gliding down on a web string from the ceiling, right in front of my eyes, and down onto my desk. It proceeds to make a few awkward movements which looked like it was having problems…
drmccoy
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Is Batesian Mimicry a form a parasitism? To what extent is the species with real defenses harmed by the defenceless species?
It seems like Müllerian mimicry would be an example of mutualism because both species would end up being eaten less by predators that only have to learn one pattern of warning symbols. But to what extent is Batesian mimicry a form a parasitism? It…
Gordon Gustafson
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12
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3 answers
Why we do not get hurt from HCl secreted in the stomach?
I read in my book that during digestion our stomach secretes hydrochloric acid ($HCl$). Why we do not get hurt from it? It was also said that mucous provides protection, but from where is it coming?
Chloritone_360
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Why do I smell flowers after sneezing?
Often when I sneeze, I smell flowers for a few seconds afterwards.
I've done some searching on the internet, and apparently it's something that is at least not entirely uncommon, although the exact smell description seems to differ. It's sometimes…
Thorarin
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What bacteria do unborn babies contain?
This Scientific American article states that "[human] infestation [by bacteria] begins at birth". This would suggest that unborn babies are free from any bacteria. However, if the mother catches a bacterial infection, her unborn baby risks catching…
James Newton
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