A tree grows at 0.5 meter per day under optimal tropical conditions. Assuming the stem consists entirely of cellulose fibers, how many D-glucose residues must be added per second to reach the above growth rate? The length of D-glucose in cellulose is about 0.45 nm.

Correct option is B

Given data:

• Tree growth rate: 0.5 meters per day
• Length of one D-glucose residue in cellulose: 0.45 nm = 0.45 × 10⁻⁹ meters

Step 1: Convert growth rate to meters per second

• The tree grows at 0.5 meters per day. First, we need to convert this into meters per second

Step 2: Calculate the number of glucose residues added per second

The length of one D-glucose residue in cellulose is about 0.45 nm, which is:  0.45 nm = 0.45 × 10⁻⁹ meters.
To find how many glucose residues are needed to produce the tree's growth in one second, we divide the growth rate by the length of one D-glucose residue:

 

This value is approximately 12860 glucose residues per second.

Therefore, the correct answer is 12800 - 12900 residues.