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1500 questions
11
votes
1 answer
Are homozygous carriers of the CCR5-Δ32 allele fully immune to all known strains of HIV?
Or is there documented evidence of even one homozygous carrier contracting HIV and staying infected?
mring
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11
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2 answers
Why do cucurbits produce so much fluid when their stems are cut?
When carrying out some germination tests on species in the Cucurbitaceae, I notice that young plants of this family produce a lot of clear fluid when they are dissected. Most plants I dissect do not produce any fluid, even ones which appear to be…
Rik Smith-Unna
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11
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3 answers
Does Human Female Meiosis II occur after fertilization with sperm?
I am reading the answer and I am getting confused by the sentence:
At the end of meiosis I females have two daughter cells and meiosis II
only occurs if and when fertilization occurs by a sperm cell.
The clause suggests me that meiosis II…
Léo Léopold Hertz 준영
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11
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1 answer
Is there any evidence that humans have faced extinction before?
Have we as a species faced extinction in the past? Resulting in a 'population bottleneck'? If so, what genetic evidence is there of this occurring?
user3795
11
votes
2 answers
Is there a bacterium that became a virus?
Is it possible for a virus to be a descendant of a bacterium that was not through horizontal gene transfer?
How I think this could happen:
Suppose a species of bacteria lives in an environment where it gets all the resources it needs to reproduce…
Raphael Augusto
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11
votes
1 answer
Coronavirus capsid missing?
According to several sources, Coronavirus is a helical virus, i.e. it should have a helical capsid. Although most sources did not labelled or pointed any kind of capsid. It was mysterious to watch diagrams of spherical envelops with no underneath…
Always Confused
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11
votes
1 answer
Does photosynthesis occur on cloudy days or does it require direct sunlight?
In my basic science classes in high school, I have learned that during photosynthesis, plants absorb sunlight and produce food by converting carbon dioxide and water into sugar and starch.
To me, this seems similar to the analogy of solar cells…
KharoBangdo
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11
votes
1 answer
Can COVID-19 affect a person a second time?
I keep hearing people are recovering from COVID-19 virus. Is there any chance that same person can become infected with COVID-19 for a second time?
Marie H
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11
votes
1 answer
What are the functions of magnetic bacteria?
I'm trying to understand why are bacteria "equipped" with magnetosomes ("intracellular organelles in magnetotactic bacteria that allow them to sense and align themselves along a magnetic field") and why and for what do they need such organelles.
syntagma
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11
votes
2 answers
How do I clean phenol contaminated RNA without losing any of the sample?
I recently extracted RNA from developing plant leaves for the first time, as part of a very long and intensive experiment. The samples were extremely precious because of the amount of effort that went into obtaining them (harvesting thousands of…
Rik Smith-Unna
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11
votes
2 answers
What is "irrational" drug/molecule design?
Both the papers "Directed evolution: the 'rational' basis for 'irrational' design" by Tobin et al. and "Rational and 'Irrational' Design of Proteins and Their Use in Biotechnology" by Nixon et al. reference the concept of "irrational" drug design,…
Seanny123
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11
votes
1 answer
Why can cats interpret things on a monitor/tv, but dogs cannot?
E.g. you can see a lot of videos where cats are smashing some mouse or spider on an ipad, but I have never seen it with a dog. I have a dog myself and I know that he sometimes responds to the sounds from the TV, but not to the images.
Why is that?
Derfder
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11
votes
1 answer
How fast do we fall asleep?
When looking at the process of sleeping, most research I find point to a group of mutually inhibitory cells which form a sort of biological "flip flop." There's cells that promote awakenness and cells that promote sleeping. The process we…
Cort Ammon
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11
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1 answer
Why is funnel web spider venom so lethal to humans and not so much for other mammals?
According to the information from this article,
People and other primates are exquisitely sensitive to funnel web venom but, intriguingly, other mammals such as mice, rabbits, guineapigs, dogs and cats are relatively immune and often survive 100…
user3795
11
votes
1 answer
What animal has fat with the highest energy density?
Fat is more energy-dense than protein and carbohydrates, it is not only an energy deposit but also an organ with many functions such as cushioning and metabolism regulations. I want to know are animal fats similar across species (composition &…
2ub
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