Which alga is characterized by the following features: has no flagella, is unicellular, has a forage value?

This is Chlorella.
Green unicellular alga without flagella. Inhabits freshwater bodies of water. It is used to obtain oxygen in closed ecosystems. In animal husbandry, it is highly efficiently used as a dietary supplement during the treatment of animals, because the cell wall contains a large number of different proteins and vitamins.