Question

1. mammals have backbones. which word in the list below is a synonym for backbones?

○ marsupial
○ vertebra
○ endotherm
○ monotreme

Explanation:

• "Marsupial" refers to a type of mammal with a pouch, not a backbone.
• "Vertebra" (plural: vertebrae) are the individual bones that make up the backbone, so it is a synonym in this context.
• "Endotherm" describes organisms that generate their own body heat, not a skeletal structure.
• "Monotreme" is a type of egg-laying mammal, not a backbone.

Answer:

vertebra