Algae 
A large group of photosynthetic organisms; Green algae are taxonomically known as Eukaryote; by contrast Blue-Green algae are classed as Prokaryote, which are single celled without a nucleus.
Algae
A large group of photosynthetic organisms; Green algae are taxonomically known as Eukaryote; by contrast Blue-Green algae are classed as Prokaryote, which are single celled without a nucleus.