Question

what do all vertebrates and invertebrates have in common?\
\bigcirc they are prokaryotic.\
\bigcirc they are covered by an outer skeleton.\
\bigcirc they are multicellular.\
\bigcirc they are bilaterally symmetrical.

Explanation:

1. Vertebrates and invertebrates are all animals. Animals are eukaryotic, not prokaryotic, so the first option is incorrect.
2. Only some invertebrates (like arthropods) have an outer skeleton; vertebrates have an internal skeleton, and many invertebrates have no skeleton at all, so the second option is wrong.
3. All animals, whether vertebrate or invertebrate, are multicellular organisms. This is a shared characteristic.
4. Not all animals are bilaterally symmetrical; some invertebrates (like jellyfish, sponges) have radial symmetry or no symmetry, so the fourth option is incorrect.

Answer:

They are multicellular.