Question

what is the major characteristic of the phylum platyhelminthes?
they have complex life cycles with many hosts
they are small and round
they are all parasitic
they are dorsoventrally flattened
question 2 (1 point)
what do tapeworms eat?
intestinal contents
red blood cells
intestinal bacteria
host tissues

Explanation:

Question 1

• Option 1: Complex life cycles with many hosts are more characteristic of some parasitic Platyhelminthes (like flukes) but not all, so not a major defining feature of the entire phylum.
• Option 2: Platyhelminthes are flat, not round. Roundworms are in Nematoda.
• Option 3: While many Platyhelminthes are parasitic, there are free - living forms (e.g., planarians), so "all parasitic" is incorrect.
• Option 4: The defining morphological feature of Platyhelminthes (flatworms) is that they are dorsoventrally flattened (flat - bodied).

• Option 1: Tapeworms live in the host's intestine and absorb nutrients from the intestinal contents of the host.
• Option 2: Red blood cells are eaten by blood - feeding parasites like some nematodes or flukes in some cases, not tapeworms.
• Option 3: Tapeworms do not eat intestinal bacteria.
• Option 4: Tapeworms do not typically eat host tissues; they absorb nutrients from the intestinal lumen.

Answer:

they are dorsoventrally flattened

Question 2