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, ...
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 ...
What are the atmospheric requirements for large dinosaurs? and are the atmospheric constituents for supporting large dinosaurs any different from the atmosphere today?
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 ...
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 ...
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 ...
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 ...
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?