When a human embryo is formed which system is created first?
The first organ to develop in the embryo is the heart. In a fetus, there is a brain, but it isn't fully developed and can't understand signals from the nervous system. Therefore the first functional organ would be the heart. But the first thing to start developing in a fetus is the nervous system. ( no that isn't an organ )
First the Big Bang occurred creating the universe. Then the matter formed into the Milky Way. Eventually some spare matter in the Milky Way formed the Solar System. But, the Big bang didn't just create the universe. It also created the matter necessary for the Milky Way, which held the matter for the Solar System.
well first off they start as a sperm and an egg, once the egg is fertilized it grows and starts to form the embryo. when the embryo is fully formed the tadpole emerges. looks pretty much the same just smaller than when it starts to morph. the tadpole then grows legs, loses the tail, and becomes a froglet, leaves the water grows and becomes a frog.
this would depend on your point of view. if you are christian, you would probably believe that the chicken came first because God created all the animals (not their eggs). if you were a scientist you would believe that for an animal to change, its genetics would have to change also and this is impossible. Therefore the change would have to take place as an embryo or egg. So the first chicken was most likely…