Which characteristic is common to both unicellular and multicellular algae?

Question

anonymous · Answer

Euglenoids, Dinoflagellates, and usually Diatoms are unicellular while Brown algae, red algae and green algae may be multicellular. Photosynthetic pigments are found in all algae like chlrophyll a and yellow or orange carotenoids.
Also, almost all algae is aquatic. 
All algae are eukaryotes and the sex organs are unicellular in all algae.

anonymous · Answer

Algae is a pretty loose term - also important to mention in addition to the above is that they're mostly the producers that support these aquatic ecosystems.

anonymous · Answer

yup that's right

anonymous · Answer

So what's the answer?

anonymous · Answer

The answer, Elvia, is the presence of chlorophyll a because it carries out photosynthesis.