BrainPop
This is a website that we use all the time in class. Although you have to pay for a membership, there are lots of free sample videos you can check out.
Cellupedia
Everything you need to know about cells plus a whole lot more... There's even an interactive game to play!
NASA for Students
Tons of information about everything you could possibly want to know about space!
NOVA: Cracking the Code of Life
If you were absent and missed any parts of this video you can watch it online at this website. There is also lots of other information and interactive learning tools available to you.
NOVA: Mars Dead or Alive
If you were absent and missed any parts of this movie, they are available for viewing online at this website.