Answer:
Invertebrates have no back bone while vertebrates have well-developed internal skeleton of cartilage and bone and highly developed brain enclosed by a skull. Their nerve cord is enclosed by the vertebrae and have well-developed sensory organs and respiratory system with either gills or lungs. A bilateral symmetry with advanced nervous system also distinguishes them from invertebrates.
answer 2
They are living animal organisms.
answer 3. There are some sea squirts or Tunicates that are primitive chordates, which in developing, abandon their bilateral symmetry and look rather like a wrinkled potato with (generally) a stalk, and they attach themselves to a holding place such as a pile. As 'adults' they do not have bilateral symmetry. There are also cephalochordata.
With such confusing features, (like the Platypus and echidna have in their way) their taxonomy has had a peripatetic history.
But in looking for 'Alike' features, reproductive organs must also be mentioned.
Answer 4;
Both are alike in being Eukaryotic, multicellular, ingestive heterotrophic and motile.