Question

which of the following best matches the cell membrane? *
a library storing books
a security gate controlling entry and exit
a power station providing energy
a trash can for waste

if you had to guess, how many cells are in the human body? *
hundreds
millions
trillions
too few to count

Explanation:

1. The cell membrane regulates what enters and exits the cell, similar to a security gate controlling entry and exit.
2. The human body is composed of trillions of cells which work together to maintain life - functions.

Answer:

1. B. A security gate controlling entry and exit
2. C. Trillions