Many Cyanobacteria Carry Out Both Oxygenic Photosynthesis and Nitrogen Fixation

Multiple Choice

Many cyanobacteria carry out both oxygenic photosynthesis and nitrogen fixation, but oxygen inhibits nitrogen fixation. How do these cyanobacteria manage both processes?

A) They trap the oxygen in special cells called heterocysts.
B) They produce cells called akinetes for photosynthesis.
C) The processes are seasonal; photosynthesis occurs in summer and nitrogen fixation takes place in winter.
D) Nitrogen fixation is sequestered in special cells called heterocysts.
E) They have special membranous structures like chloroplasts to separate the processes within the cell.