The updatePictureState method of DrawingApp periodically saves a
frame to disc and the frequency with which it does this can be altered by changing the interval number
(each save does cause the animation to pause for a fraction of a second as it isn't run on a separate
Meiosis, the form of cell division unique to egg and sperm production, sets the stage for sex determination by creating sperm that carry either an X or a Y sex chromosome. But what is it about the X or Y that determines sex? Before a meiotic cell divides, its two sets of chromosomes come together and cross over, or swap, segments. The first animation shows normal crossing over, where the X and Y chromosomes exchange pieces only at their tips. The second animation shows a rare mistake in which the Y chromosome transfers a gene called SRY to the X chromosome, resulting in sex-reversed babies. Studies of sex-reversed individuals led researchers to identify the master switch for sex determination, the SRY gene, which tells a fetus to become a boy.
Water Cycle - Earthguide Animated Diagram
Two of the science's most illustrious expounders were Buffon and Oliver Goldsmith, from both of whom we learn (L'Histoire generale des animaux and A History of Animated Nature) that the domestic cow sheds its horn every two years.