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1500 questions
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2 answers
Why do sparrows jump instead of walk when they are not flying?
I want to talk about sparrows, one of the most common birds around the world. I noticed that when one slowly walks into them (so that they are not frightened enough to fly away), these tiny birds would jump away, rather than walk away, as if they…
nalzok
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13
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What is the difference between cytosol and cytoplasm?
I've generally seen cytosol defined as the solution inside cells minus the organelles, cytoskeleton, etc and cytoplasm as the cytosol plus the organelles, cytoskeleton, etc. This naturally leads to the impression that cytosol is the cytoplasm minus…
CircleSquared
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13
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4 answers
Examples of enzymes working in reverse?
I have always been taught that enzymes can catalyze both the forward and reverse reaction, and will increase the reaction rate in both directions. I understand that the thermodynamics of the reaction are not altered by the enzyme, but I have yet to…
Arcadium
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13
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Do colour-blind people see white?
I know that white colour is perceived on excitation of red, blue and green cones simultaneously.
It is also said that a colour-blind person doesn't see a particular colour and just perceives it as a shade of grey.
If their (for example all red)…
JM97
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13
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1 answer
Identification of a purple flower
What is this purple flower? Picture taken from a garden in India.
HPL
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13
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1 answer
Beetle identification - Kakadu NP, NT, Australia
I am trying to ID this beetle;
Size: not too big - approximately 2 cm (3/4 inch)
Where: Litchfield National Park, Northern Territory, Australia;
When: Southern hemisphere's spring, early September; the end of the dry season;
Time of day: night.…
AliceD
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13
votes
2 answers
Why is uracil, rather than thymine, used in RNA?
This question was posed on SE Biology some time ago, but all the answers, including the accepted one, answered a different question instead: “Why is thymine, rather than uracil, used in DNA?”. I therefore changed the title to match the answers,…
David
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13
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1 answer
Plant identification — Phuket, Thailand
Found in Phuket, Thailand. White flower, five petals, 5 stamens. Strings of flowers hanging down from red stems. Buds white, tear-drop shape.
RHA, Here are the leaves. The flowers hang from a bush about 6 foot (2 metres Tall)
Bli, thanks, but not…
Alasdair Forbes
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13
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3 answers
Is vermiform appendix no more a vestigial organ?
The appendix has a role in the immune response.
So is it therefore recently removed from the list of vestigial organs?
Mesentery
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13
votes
4 answers
Why do plants store energy as carbohydrates and not as fats?
In my introductory biology class, we are learning about biomolecules. The textbook says fats are a more efficient energy store than carbohydrates.
So my question is - why would plants store their energy as carbohydrates and not as fats, if fats are…
Sean_J
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13
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3 answers
Is cancer caused by vitamin B17 deficiency?
I have read in an article on the internet that cancer is caused due to deficiency of vitamin B17 which has been removed from our diets long ago in the western food. But some people say that vitamin B17 does not work. So, is it deficiency of vitamin…
Mesentery
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13
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1 answer
Dorsal vs Posterior and Ventral vs Anterior
From prior reading, I thought that Dorsal is the same as Posterior and Ventral is the same as Anterior. However, when I checked in google images for these anatomical terms for a horse (just to strengthen my concept), i found that Dorsal is not the…
MrAP
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13
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1 answer
How much energy does human body fat contain?
I have been reading the Wikipedia article about food energy, but as I'm not a biologist, I don't really understand it properly, so I came here to ask you guys.
My question is: If a human body needs X kcal of energy and it's taking it from the stored…
Frantisek
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13
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3 answers
How do we know Neanderthals DNA?
According to this article, a small amount of Neanderthal DNA was introduced into the modern human gene pool. How do biologists even know what the Neanderthals' DNA look like?
The article doesn't mention how the science recognize what the…
Grasper
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13
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1 answer
Will a bone marrow transplant change one's blood type?
Will a bone marrow transplant change one's blood type?
Or is the donor blood type matched with the person before transplant?
Gabriel Fair
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