The study of the internal structure of organisms.

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Why Is Most Life Symmetrical Externally But Not Internally?

Mammals, reptiles, arachnids, insects, etc are all as far as I am aware symmetrical in appearance. Take a human for instance, make a line from the top of our head right down the middle. However, ...
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1answer
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Evolutionarily, why do male rats and horses lack nipples?

Developmentally male rats don't have nipples because (reddit) Testosterone release in the fetal male rat happens before the stage of mammogenesis where the teat is formed whereas other species ...
7
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1answer
593 views

What are the atmospheric requirements for large dinosaurs?

What are the atmospheric requirements for large dinosaurs? and are the atmospheric constituents for supporting large dinosaurs any different from the atmosphere today?
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2answers
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Why do small organisms make faster movements than big organisms?

I hesitated to ask this question because it seems so obvious and intuitive. However, I am not able to explain this tendency. Background It seems to me that small organisms make faster movements than ...
4
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1answer
127 views

Can defibrillation be done with a car battery?

Can successful defibrillation be done with a car battery? Is it POSSIBLE for this to work? Let's say you are stuck on a very remote place and something happens to someone... Moreover, can you jump ...
3
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1answer
590 views

Is there a difference between pig and cow anatomy that makes religious slaughter of the latter less painful?

This question is not for the squeamish. I was told that non-Kosher animals like pigs have a different anatomy in their neck compared to kosher animals like cows such that the Shechita method of ...
4
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1answer
80 views

What causes the opaque green colour in Lepidoptera?

Link here to what I mean by 'opaque' colouration on the insect, the colour intensity remains constant despite changes in light intensity and angle (not shown by the picture but the moth exhibits this ...
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0answers
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Terrestrial Vertebrate Limbs

This question is regarding the conversation that took place here: Why don't mammals have more than 4 limbs?. I'm not sure if someone mentioned this and I just missed it, but everyone is talking ...
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Why do male rats and horses lack nipples? [duplicate]

I have read many articles about why male rats and horses lack nipples, however, I still don't understand why! Do male rats, mice, and horses have nipples in early embryonic life and then lose them?