I think it's electric force. Not 100% sure but I hope it's right.
Translation happens between the two sub units of ribosomes.....as there the RNA converts into amino acid ! because RNA is read by tRNA and only in ribosomes!
It is true that studies of animals show that they play only when the physical survival needs have been met; however, there is growing evidence that for children, play is crucial in terms of biological evolution as well as individual development.