How Do Some Cyanobacteria Fix Nitrogen While Growing Aerobically

Question

How do some cyanobacteria fix nitrogen while growing aerobically?
A) They do not, because nitrogenase is destroyed by oxygen.
B) They use special cells called heterocysts that protect the enzyme.
C) They use spores that protect the enzyme.
D) They do it using no special structures or mechanisms.
E) They live symbiotically with other organisms that protect the enzyme.

Accepted Answer

Some cyanobacteria have specialized cells called heterocysts that lack oxygen and protect the nitrogenase enzyme from oxygen damage, allowing nitrogen fixation to occur even in the presence of oxygen.