Timelapse footage of dividing cells in the fertilised egg of a common frog (Rana temporaria). After fertilisation the egg becomes a zygote, which contains genes from both the mother and father. This cell divides by mitosis, forming a ball of cells called a morula, then developing a central cavity and becoming a blastula. Cells on the outside, inside and middle of this wall take different roles in the developing embryo, ultimately forming the tissues and organs of the organism. Filmed with a frame captured every two minutes over more than 30 hours. Magnification roughly x6 on the camera sensor.