Suggest hypotheses for which lifestyle a plate-shaped thallus is preferable to a filament-shaped body.

If there is a current in the reservoir, then the algae predominantly have a lamellar shape, because breaking a plate is more difficult than a thread. And the plate has more points of support (attachment).

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.