Movement of a Cilium

CONTROLLING THE ANIMATION:
Wait for the animation to load completely and play through once. To stop the animation, click on the "pause" button. To see the frame that precedes the paused frame, press the "previous" button. To see the frame that follows the paused frame, click on the "next" button. To resume the animation, click on the "play" button.

PROCEDURE:
1) Advance the animation to the frame showing the first phase of the cilium's power stroke. NOTE: Power stroke phases for the cilium are shown in green.
2) If the black base to which the cilium is attached was a freely swimming organism, in which direction would the power stroke tend to propel the organism?  [To the left, or to the right?]  In which direction would water tend to be moved by the power stroke of the cilium?
3) Next, advance the animation to view recovery stroke phases, shown in red. What is different about the cilium's orientation during the recovery stroke, as compared to the power stroke. Explain how these differences in configuration contribute to the efficiency of ciliary propulsion..

Click here to see non-interactive GIF animation 
Software for controlling interactive animations was developed by TOM DREWES