Which of the following is a true description of the green alga Spirogyra sp.? Select one:
a. The alga has a branched, multicellular, filamentous habit.
b. The chloroplast with its pyrenoids is arranged spirally throughout each filament.
c. Most of the interior of each cell is occupied by cytoplasm.
d. Gametic meiosis takes place via the process of conjugation between filaments.