What is a prepositional phrase for camels are animals that have humps on their backs?

You can't create a prepositional phrase for the entire sentence "Camels are animals that have humps on their backs." Prepositional phrases modify nouns or verbs, but this sentence is a complete statement.

However, you *can* create a prepositional phrase for part of the sentence:

* "on their backs" is a prepositional phrase that modifies the verb "have."

Here's how you could use it in a sentence:

* Camels are animals that have humps on their backs.