Question

In which phylum do organs and organ systems first appear?

Answer 1

Answer: flatworms

Explanation: Platyhelminthes, flatworms. this tissue covers the whole surface of the body. It is made up of cells closely packed and ranged in one or more layers.

Answer 2

Platyhelminthes

Step-by-step explanation:

Platyhelminthes, flatworms. this tissue covers the whole surface of the body. It is made up of cells closely packed and ranged in one or more layers.