For 17 the answer is d
for 18 the answer is b
Secondary succession is a process started by an event (example forest fire) that reduces an already established ecosystem
Answer:
Well, the primary distinction between these two types of organisms is that eukaryotic cells have a membrane-bound nucleus and prokaryotic cells do not. ... Prokaryotes, on the other hand, have no membrane-bound organelles. Another important difference is the DNA structure.
Answer:
nitrogen fixation, nitrification, denitrification, anammox, and ammonification
Explanation: