Have a pseudocoelom and are the simplest animals that have a complete digestive tract.

Nematodes have a pseudocoelom and are the simplest animals that have a complete digestive tract.

Nematodes also known as roundworms are animals well adapted to variety of environments, meaning that are ubiquitous. Nematodes are small, bilaterally symmetric with ornamented ring body structures. Their body is covered with cuticle that works with the muscles beneath it to create a hydroskeleton. There are free-living species and parasitic species of Nematoda.  

label a cell membrane

label b cytoplasm

label c ribosomes

label d dna

the membrane forms the outside of the cell

cytoplasm is the liquid within

ribosomes are the components within that distribute rna

the dna is the genetic make-up

i think this picture will you.