Describe the characteristics of Euglenoids with an example.

(N/A) Euglenoids are a group of freshwater organisms found in stagnant water. Their key characteristics are as follows:
$1$. Pellicle: Instead of a cell wall,they have a protein-rich layer called a $Pellicle$ which makes their body flexible.
$2$. Photosynthetic and Heterotrophic: They possess chlorophyll $a$ and $b$ identical to higher plants,allowing them to perform photosynthesis in the presence of sunlight. However,in the absence of sunlight,they behave like heterotrophs by predating on other smaller organisms.
$3$. Flagella: They typically possess two flagella,one short and one long.
$4$. Mixotrophic Nutrition: Due to their dual mode of nutrition (autotrophic and heterotrophic),they are described as mixotrophic.
Example: $Euglena$.