What does totipotent refer to when discussing stem cells?
a. the ability to pass through the plasma membrane
b. the ability to clone oneself
c. having limited mobility
d. the ability to differentiate into multiple cell types
Question 2
The first prokaryotic cells appear in the fossil record ___________ years ago.
a. 3.4 billion
b. 1.5 billion
c. 800 million
d. 100 million