Final answer:
Euglenophyta reproduce asexually by cell division, without observed sexual reproduction.
Step-by-step explanation:
Euglenophyta, commonly known as Euglena, reproduce through a type of asexual reproduction where cells divide. This form of reproduction is common among single-celled organisms, including various types of algae and protozoa. No form of sexual reproduction has been observed in Euglenophyta, making their reproductive process relatively straightforward compared to other organisms that have complex life cycles involving both sexual and asexual stages.