Give scientific reasons :
Euglena is also called plant animal. 

Explanation

Euglena is a taxonomic puzzle since, it show both plant and animal characters. Absence of cell wall is an animal feature and presence of chloroplast is a plant character of Euglena. They also have mixotrophic nutrition. In the presence of sunlight, they can photosynthesis their food and in absence of sunlight they are heterotrophs by predating other smaller organisms.