Female mammals have two x chromosomes, one from their mother and one from their father. during x inactivation, one x chromosome in each embryonic cell is randomly inactivated; therefore, all of the tissues that arise from that cell have the same inactivated x chromosome. female mammals are therefore considered to be of the maternal and paternal cells.

about 40,000,000 results (0.81 seconds)  

search results

what do the different brain waves do?

explanation:

brainwaves are produced by synchronised electrical pulses from masses of neurons communicating with each other. brainwaves are detected using sensors placed on the scalp. brainwave speed is measured in hertz (cycles per second) and they are divided into bands delineating slow, moderate, and fast waves.