Which group of chordates does not possess true backbones?
a. lampreys
b. frogs and toads
c. birds
d. crocodilians

The only group of chordates that does not possess true backbones are

A) Lampreys.

All the other answer choices DO possess backbones, so that would leave A as the answer.

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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