According to the cladogram, which group of organisms is the closest relative to chordates?

What molecules will be best used to compare different species with the exact same sequence of amino acids? why would two species have the same protein even if the molecules in question is different? (hint: transcription to translation to protein).

Which macromolecule catalyzes chemical reactions this be considered enzyme chemical reactions thus he considering enzymes

What factors contribute to the effect an environmental toxin has on the human body?