Answer:
Explanation:
Placoderms were the first jawed fish; their jaws likely evolved from the first of their gill arches. in spanish
placodermos
your body and nature is about human life
Answer:
protein-coupled receptors.
Answer:toxic
Explanation:
A ureotelic organism excretes excess nitrogen as urea. Urea is less toxic and needs less water in comparison to Ammonia. Ureotelic organisms include cartilaginous fish, few bony fishes, adult amphibians and mammals including humans. The uricotelic organism excretes uric acid or its salts