Heterocyst-forming cyanobacteria differentiate highly specialized cells to provide fixed nitrogen to the vegetative cells in a filament. In the presence of a source of combined nitrogen such as nitrate or ammonium, Anabaena PCC 7120 grows as long filaments containing hundreds of photosynthetic vegetative cells.
The ancient Egyptians used the stars to tell when a flood was going to happen. Every summer a flood would happen but this also happened when the bright star Sirius rose before the sun.
Hope that helped ^^
Inside the chloroplast (a membrane-bound organelle present in plant cells)
Answer:
nitrogen that cannot be used
A decrease in the population of bears
