Answer:
5040
Explanation:
"organism" has 8 letters. Since the g is not to be permutated, let's take it out, and we're left with 7 letters.
For the first position we have 7 options. For the second position we have 6 options, etc., so 7*6*5*4*3*2*1 = 7! = 5040.
The "g" we just insert at the 3rd position, it doesn't play any role in the counting.