What are the two major types of animals

Vertebrates and Invertebrates

The reason why "Vertebrates and Invertebrates" would be the correct answer because these are the major types of animals in this world.

Vertebrates are animals that has a spine (spinal column) or backbone. Vertebrates are animals like reptiles, mammals, fishes, birds, amphibians, and etc. These animals have a spine or backbone because their body structure needs it in order to live their lives. The spine or backbone keeps those animals up and allow them to be functional.

Invertebrates are animals that do not have a spine (spinal column) or backbone. These animals do not have a spine or backbone because their body structure doesn't need it. These animals could be arthropods, worms, insects, and etc.

nucleic acid molecules are incredibly complex, containing the code that guarantees the four different nucleotide units comprise dna, the nucleic acid of interest to the genealogist. and one of four nitrogen-containing molecules called nucleotides

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