Video Transcript
Which of the following is not a
typical characteristic of a flatworm, or platyhelminth? (A) Having a body divided into
distinct segments. (B) Having a body composed of three
layers. (C) Having a bilaterally
symmetrical body. Or (D) having a flattened body and
a head.
Organisms belonging to the phylum
Platyhelminthes, also known as flatworms, have many characteristics in common. Let’s look through the answer
choices to see which do match typical characteristics of flatworms.
First, as the name suggests,
flatworms are flat, with the anterior and posterior of their bodies being easily
identifiable. So we can eliminate answer (D). Flatworms are triphoblastic. This means that their bodies are
made up of three layers. So, we can also eliminate answer
(B). In addition, flatworms are
bilaterally symmetrical. This means if they were cut in half
lengthwise, both halves would be identical. So we can eliminate answer (C) as
well. Flatworms are not segmented.
So the correct answer to this
question is (A). Flatworms do not typically have
bodies divided into distinct segments.
